WTNT41 KNHC 042056
TCDAT1
TROPICAL STORM IDA DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
400 PM EST WED NOV 04 2009
 
SATELLITE IMAGES SHOW THAT...ALTHOUGH CONVECTION HAS WEAKENED THIS
AFTERNOON...THE OVERALL CLOUD PATTERN CONTINUES TO BE WELL-ORGANIZED
WITH STRONG BANDS IN THE NORTHERN SEMICIRCLE OF THE SYSTEM.  AN AIR
FORCE RESERVE RECONNAISSANCE PLANE FOUND MAXIMUM FLIGHT-LEVEL WINDS
OF 53 KT...SFMR WINDS OF 48 KT...AND A FALLING MINIMUM CENTRAL
PRESSURE OF 996 MB.  THESE DATA SUPPORT AN INITIAL WIND SPEED OF
ABOUT 50 KT...AND THUS THE SYSTEM HAS BEEN NAMED IDA.
 
THE INITIAL MOTION APPEARS TO HAVE TURNED SLIGHTLY TO THE LEFT...AND
IS NOW 300/5.  IDA IS MOVING THROUGH AN AREA OF LIGHT STEERING
BETWEEN A RIDGE OVER THE NORTH-CENTRAL CARIBBEAN SEA AND A WEAK
TROUGH OVER THE SOUTHWESTERN GULF OF MEXICO. THERE IS BETTER
AGREEMENT IN THE MODELS THIS AFTERNOON ON THE STORM SLOWLY MOVING
TO THE NORTHWEST...THEN TO THE NORTH AROUND THE WESTERN PART OF THE
CARIBBEAN RIDGE.  ONLY THE UKMET MODEL NOW KEEPS THE SYSTEM OVER
WATER WITHOUT SIGNIFICANT LAND INTERACTION.  THE OFFICIAL NHC
FORECAST IS SHIFTED WESTWARD AND IS FASTER THAN THE PREVIOUS ONE.
 
ALTHOUGH ENVIRONMENTAL CONDITIONS FAVOR STRENGTHENING...IDA DOES NOT
HAVE MUCH MORE TIME LEFT BEFORE IT MOVES OVER NICARAGUA.   THE
INTENSITY FORECAST IS CLOSE TO PREVIOUS ONE IN THE SHORT-TERM...
SHOWING SOME STRENGTHENING OF IDA...AND THEN REDUCED THEREAFTER DUE
TO THE EFFECTS OF LAND.  IN A FEW DAYS...THE ATMOSPHERIC ENVIRONMENT
COULD ALLOW FOR SOME REINTENSIFICATION OF THE SYSTEM OVER THE
NORTHWESTERN CARIBBEAN SEA. HOWEVER... IT IS ENTIRELY POSSIBLE THAT
THE TROPICAL CYCLONE COULD DISSIPATE OVER THE HIGHER TERRAIN OF
CENTRAL AMERICA.
 
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES FROM EXTREMELY HEAVY
RAINS ARE EXPECTED TO BE THE BIGGEST THREAT FROM IDA.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/2100Z 12.0N  82.7W    50 KT
 12HR VT     05/0600Z 12.4N  83.3W    55 KT
 24HR VT     05/1800Z 13.0N  84.1W    40 KT...INLAND
 36HR VT     06/0600Z 13.7N  84.6W    30 KT...INLAND
 48HR VT     06/1800Z 14.5N  85.0W    25 KT...INLAND
 72HR VT     07/1800Z 16.0N  85.5W    25 KT...OVER WATER
 96HR VT     08/1800Z 18.0N  86.0W    35 KT
120HR VT     09/1800Z 20.5N  86.5W    40 KT
 
$$
FORECASTER BLAKE/PASCH
 

WTNT41 KNHC 050235
TCDAT1
TROPICAL STORM IDA DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
1000 PM EST WED NOV 04 2009
 
SINCE THE LAST AIRCRAFT PENETRATION OF THE STORM...THE CLOUD PATTERN
OF IDA HAS REMAINED WELL ORGANIZED WITH A PROMINENT COLD-TOPPED CDO
AND SOME BANDING FEATURES OVER THE NORTHERN SEMICIRCLE.  A RECENT
SSMIS OVERPASS REVEALED A BANDING-TYPE EYE IN MICROWAVE IMAGERY. 
DVORAK INTENSITY ESTIMATES WERE 45 KT FROM TAFB AND SAB BUT THESE
ARE CONSTRAINED BY THE RULES OF THE TECHNIQUE.  BASED ON THE
EARLIER AIRCRAFT DATA AND CURRENT ORGANIZATION OF THE SYSTEM...THE
CURRENT INTENSITY IS ESTIMATED TO BE 55 KT.  THE UPPER-LEVEL
OUTFLOW IS WELL DEFINED AND THERE REMAINS A SHORT PERIOD PRIOR TO
LANDFALL FOR IDA TO STRENGTHEN A LITTLE MORE.  RAPID WEAKENING IS
LIKELY WHEN THE CYCLONE INTERACTS WITH THE MOUNTAINOUS TERRAIN OF
CENTRAL AMERICA.  IDA IS PROJECTED TO MOVE BACK OVER THE WATERS OF
THE CARIBBEAN SEA IN ABOUT 3 DAYS.  THE INTENSITY FORECAST IN THE
LATTER PART OF THE PERIOD IS HIGHLY UNCERTAIN...HOWEVER...BECAUSE
IT IS NOT CLEAR WHETHER THE TROPICAL CYCLONE WILL SURVIVE ITS
TRANSIT OVER LAND.

THE ESTIMATED INITIAL MOTION IS NOW NORTHWESTWARD OR 315/6.  IDA IS
BEING STEERED BY THE FLOW BETWEEN A WEAK RIDGE OVER THE
NORTH-CENTRAL CARIBBEAN SEA AND A WEAK TROUGH OVER THE SOUTHWESTERN
GULF OF MEXICO.  AS THE RIDGE BUILDS NORTHWARD OVER THE NEXT FEW
DAYS...THE TROPICAL CYCLONE SHOULD GRADUALLY TURN TOWARD THE
NORTH-NORTHWEST.  MOST OF THE TRACK MODELS ARE IN FAIR AGREEMENT ON
A GENERAL NORTHWARD OR NORTH-NORTHWESTWARD MOTION...BUT VARY
SIGNIFICANTLY IN FORWARD SPEED.  THE OFFICIAL FORECAST IS A BLEND
OF THE MODEL CONSENSUS AND THE PREVIOUS NHC TRACK.

THE BIGGEST IMPACT OF THIS SLOW-MOVING SYSTEM WILL LIKELY BE
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES CAUSED BY EXTREMELY
HEAVY RAINS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/0300Z 12.5N  83.1W    55 KT
 12HR VT     05/1200Z 12.9N  83.6W    60 KT...INLAND
 24HR VT     06/0000Z 13.5N  84.0W    40 KT...INLAND
 36HR VT     06/1200Z 14.3N  84.4W    30 KT...INLAND
 48HR VT     07/0000Z 15.1N  84.6W    25 KT...INLAND
 72HR VT     08/0000Z 17.0N  85.0W    35 KT...OVER WATER
 96HR VT     09/0000Z 19.5N  85.5W    40 KT
120HR VT     10/0000Z 21.5N  86.5W    45 KT
 
$$
FORECASTER PASCH/ROBERTS
 

WTNT41 KNHC 050836
TCDAT1
TROPICAL STORM IDA DISCUSSION NUMBER   4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
400 AM EST THU NOV 05 2009
 
THE SATELLITE PRESENTATION OF IDA HAS CONTINUED TO IMPROVE OVER THE
PAST FEW HOURS. EARLIER THERE WAS A LARGE EXPANSION OF COLD CLOUD
TOPS IN A SYMMETRIC CENTRAL DENSE OVERCAST WHILE IN THE LAST HOUR OR
TWO THE COLDEST TOPS HAVE TAKEN ON A MORE BANDED APPEARANCE. DVORAK
INTENSITY ESTIMATES AT 0600 UTC WERE 55 KT FROM TAFB AND SAB...
HOWEVER AIRCRAFT RECONNAISSANCE FOUND THAT IDA WAS ALREADY THAT
STRONG YESTERDAY WHEN IT HAD A MUCH LESS IMPRESSIVE SATELLITE
APPEARANCE.  THEREFORE...THE INITIAL INTENSITY IS RAISED TO 60 KT
FOR THIS ADVISORY.  WHILE THERE IS ONLY A SMALL WINDOW FOR
ADDITIONAL STRENGTHENING...THE HURRICANE WATCH FOR PORTIONS OF THE
COAST OF NICARAGUA REFLECTS THE SMALL CHANCE THAT IDA COULD REACH
HURRICANE STATUS AS IS MAKES LANDFALL.  AFTER LANDFALL...WEAKENING
IS FORECAST AS THE CENTER IS EXPECTED TO REMAIN OVER LAND FOR THE
NEXT COUPLE OF DAYS.  THE TRACK FORECAST TAKES IDA BACK OVER THE
NORTHWESTERN CARIBBEAN SEA AFTER 48 HOURS...AND THE INTENSITY
FORECAST SHOWS SOME STRENGTHENING AT 72 HOURS AND BEYOND.  HOWEVER
...THERE IS A LARGE DEGREE OF UNCERTAINTY AT THIS TIME RANGE...SINCE
IDA MAY NOT SURVIVE LONG ENOUGH TO REACH WATER AGAIN.
 
THE INITIAL MOTION ESTIMATE IS 310/06. THROUGH 48 HOURS THE
MULTI-MODEL CONSENSUS IS IN GOOD AGREEMENT WITH THE PREVIOUS
FORECAST...AS IDA IS EXPECTED TO TURN NORTHWARD BETWEEN A WEAK
MID-LEVEL RIDGE OVER THE NORTH-CENTRAL CARIBBEAN SEA AND A
WEAK TROUGH OVER THE SOUTHERN GULF OF MEXICO.  BEYOND THAT TIME...
MUCH OF THE GUIDANCE HAS SHIFTED WESTWARD WITH LARGE DIFFERENCES IN 
FORWARD SPEED AS WHATEVER IS LEFT OF IDA INTERACTS WITH A MID-LEVEL
TROUGH DIGGING INTO THE NORTHWESTERN GULF OF MEXICO.  GIVEN THE
LARGE SPREAD IN THE GUIDANCE...A SLOW NORTH-NORTHWESTWARD MOTION IS
SHOWN AT DAYS 3 THROUGH 5.  THIS IS IN GOOD AGREEMENT WITH THE
PREVIOUS FORECAST AND ON THE EASTERN SIDE OF THE GUIDANCE
ENVELOPE...WITH THE EXCEPTION OF THE GFDL WHICH IS A FAR EASTERN
OUTLIER.
 
THE BIGGEST IMPACT OF THIS SLOW-MOVING SYSTEM WILL LIKELY BE
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES CAUSED BY EXTREMELY
HEAVY RAIN OVER PORTIONS OF NICARAGUA AND HONDURAS OVER THE NEXT
COUPLE OF DAYS. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/0900Z 12.8N  83.4W    60 KT
 12HR VT     05/1800Z 13.3N  83.9W    45 KT...INLAND
 24HR VT     06/0600Z 13.9N  84.3W    35 KT...INLAND
 36HR VT     06/1800Z 14.7N  84.6W    30 KT...INLAND
 48HR VT     07/0600Z 15.7N  84.8W    25 KT...INLAND
 72HR VT     08/0600Z 18.0N  85.5W    35 KT...OVER WATER
 96HR VT     09/0600Z 20.0N  86.0W    40 KT
120HR VT     10/0600Z 22.0N  87.0W    45 KT
 
$$
FORECASTER BRENNAN/CANGIALOSI
 

WTNT41 KNHC 051445
TCDAT1
HURRICANE IDA DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
1000 AM EST THU NOV 05 2009
 
THE SATELLITE PRESENTATION OF IDA CONTINUED TO IMPROVE UP UNTIL
LANDFALL...WHICH OCCURRED NEAR TASBAPAUNI NICARAGUA...OR ABOUT
60 MILES NORTH-NORTHEAST OF BLUEFIELDS.  AN 1117 UTC SSMI MICROWAVE
IMAGE SHOWED A WELL-DEFINED EYE THAT WAS LOCATED JUST INLAND AT THAT
TIME.  A BLEND OF SUBJECTIVE AND OBJECTIVE DVORAK CLASSIFICATIONS
AROUND THE TIME OF LANDFALL SUPPORTED AN INTENSITY OF 65 KT.  SINCE
THE SATELLITE PRESENTATION HAS NOT SIGNIFICANTLY DEGRADED...THE
ADVISORY INTENSITY WILL REMAIN 65 KT.  IDA IS EXPECTED TO WEAKEN
AS IT MOVES FARTHER INLAND DURING THE NEXT DAY OR SO.  THE FORECAST
TRACK BRINGS THE CENTER BACK OVER THE NORTHWESTERN CARIBBEAN SEA IN
A COUPLE OF DAYS...AND THE INTENSITY FORECAST SHOWS SOME
STRENGTHENING AFTER THAT TIME.  UPPER-LEVEL SOUTHWESTERLY WINDS ARE
EXPECTED TO PRODUCE MODERATE SHEAR OVER THE SYSTEM AND ONLY MODEST
STRENGTHENING IS FORECAST AFTER IDA EMERGES OVER WATER. THERE
REMAINS A LARGE DEGREE OF UNCERTAINTY IN THE LONGER RANGE
FORECAST...SINCE IDA MAY NOT SURVIVE ITS PASSAGE OVER LAND.
 
THE INITIAL MOTION ESTIMATE IS 315/05. IDA IS EXPECTED TO TURN
NORTHWARD BETWEEN A MID-LEVEL RIDGE OVER THE CENTRAL CARIBBEAN AND
A WEAK TROUGH OVER THE SOUTHWESTERN GULF OF MEXICO.  THE TRACK
GUIDANCE IS IN GOOD AGREEMENT ON THIS SCENARIO...AND THE NEW
OFFICIAL FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY DURING THE
FIRST 36 TO 48 HOUR OF THE FORECAST PERIOD.  THEREAFTER...THE TRACK
MODELS MOVE IDA IN A GENERAL NORTH TO NORTH-NORTHWEST DIRECTION 
INTO THE SOUTHERN GULF OF MEXICO.  THE NEW NHC TRACK IS SLIGHTLY
RIGHT OF...AND A LITTLE FASTER THAN THE PREVIOUS FORECAST.  THE NHC
TRACK IS A LITTLE SLOWER THAN THE MODEL CONSENSUS...IN BEST
AGREEMENT WITH THE ECMWF.
 
THE BIGGEST IMPACT OF THIS SLOW-MOVING SYSTEM DURING THE NEXT FEW
DAYS WILL LIKELY BE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES
CAUSED BY EXTREMELY HEAVY RAIN OVER PORTIONS OF NICARAGUA AND
HONDURAS.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/1500Z 13.1N  83.7W    65 KT
 12HR VT     06/0000Z 13.6N  84.0W    45 KT...INLAND
 24HR VT     06/1200Z 14.3N  84.2W    35 KT...INLAND
 36HR VT     07/0000Z 15.0N  84.4W    30 KT...INLAND
 48HR VT     07/1200Z 16.0N  84.5W    25 KT...OVER WATER
 72HR VT     08/1200Z 18.4N  85.4W    40 KT
 96HR VT     09/1200Z 21.0N  86.5W    45 KT
120HR VT     10/1200Z 23.5N  87.0W    45 KT
 
$$
FORECASTER BROWN/BLAKE
 

WTNT41 KNHC 052038
TCDAT1
TROPICAL STORM IDA DISCUSSION NUMBER   6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
400 PM EST THU NOV 05 2009
 
THE SATELLITE PRESENTATION OF IDA HAS GRADUALLY DEGRADED SINCE IT
MADE LANDFALL THIS MORNING...AND THE INITIAL INTENSITY HAS BEEN
LOWERED TO 50 KT.
 
IDA APPEARS TO HAVE SLOWED AND TURNED MORE NORTH-NORTHWESTWARD WITH
AN INITIAL MOTION ESTIMATE OF 330/3.  THE FORECAST REASONING HAS
NOT CHANGED SINCE THIS MORNING AND THE TRACK GUIDANCE REMAINS IN
REASONABLY GOOD AGREEMENT ON A NORTH-NORTHWESTWARD TO NORTHWARD
MOTION DURING THE NEXT COUPLE DAYS.  THE GUIDANCE HAS SHIFTED A
LITTLE EASTWARD AND IS A LITTLE FASTER DURING THE FIRST 48 HOURS.
AFTER THAT...THE MODELS SHOW A GENERAL NORTH-NORTHWESTWARD TRACK
INTO THE SOUTHERN GULF OF MEXICO.  THERE REMAINS A LARGE SPREAD IN
THE GUIDANCE AFTER 72 HOURS.  THE GFDL AND GFS ARE ALONG THE EASTERN
SIDE OF THE GUIDANCE ENVELOPE...WHILE THE NOGAPS IS ALONG THE
WESTERN EDGE.  THE OFFICIAL FORECAST IS NEAR THE MIDDLE THE
ENVELOPE...BUT REMAINS A LITTLE SLOWER THAN THE MODEL CONSENSUS.
 
IDA SHOULD CONTINUE TO WEAKEN AS IT MOVES OVER NORTHEASTERN
NICARAGUA AND EASTERN HONDURAS DURING THE NEXT DAY OR SO.  SOME
RESTRENGTHENING IS FORECAST AFTER THE CENTER EMERGES INTO THE
NORTHWEST CARIBBEAN SEA. HOWEVER...CONDITIONS DO NOT APPEAR TO BE
EXTREMELY FAVORABLE FOR INTENSIFICATION AS UPPER-LEVEL SOUTHWESTERLY
WINDS ARE EXPECTED TO PRODUCE MODERATE SHEAR OVER THE SYSTEM. 
LATER IN THE PERIOD WESTERLY WINDS BECOME QUITE STRONG AND SHOULD
ARREST FURTHER STRENGTHENING.  THERE REMAINS A LARGE DEGREE OF
UNCERTAINTY IN THE LONGER-RANGE FORECAST...SINCE IDA MAY NOT
SURVIVE ITS PASSAGE OVER LAND.

THE BIGGEST IMPACT OF THIS SLOW-MOVING SYSTEM DURING THE NEXT COUPLE
OF DAYS WILL LIKELY BE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES
CAUSED BY EXTREMELY HEAVY RAIN OVER PORTIONS OF NICARAGUA AND
HONDURAS.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/2100Z 13.3N  83.7W    50 KT
 12HR VT     06/0600Z 13.9N  83.9W    40 KT...INLAND
 24HR VT     06/1800Z 14.9N  84.1W    30 KT...INLAND
 36HR VT     07/0600Z 16.0N  84.3W    35 KT...OVER WATER
 48HR VT     07/1800Z 17.1N  84.6W    40 KT
 72HR VT     08/1800Z 19.6N  85.7W    45 KT
 96HR VT     09/1800Z 22.5N  87.0W    45 KT
120HR VT     10/1800Z 25.0N  87.0W    45 KT
 
$$
FORECASTER BROWN
 

WTNT41 KNHC 060241
TCDAT1
TROPICAL DEPRESSION IDA DISCUSSION NUMBER   7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
1000 PM EST THU NOV 05 2009
 
SURFACE OBSERVATIONS AND CONVENTIONAL SATELLITE IMAGERY INDICATE
THAT IDA HAS WEAKENED TO A TROPICAL DEPRESSION.  WHAT REMAINS OF THE
DIMINISHING DEEP CONVECTION IS CURRENTLY CONFINED TO NORTHWEST AND
NORTHEAST QUADRANTS.  SOME FURTHER WEAKENING IS LIKELY DURING THE
NEXT 12 TO 24 HOURS AS IDA CONTINUES ON A GENERAL NORTHWARD TRACK
OVER NORTHEASTERN NICARAGUA AND EASTERN HONDURAS. AROUND THE 36
HOUR PERIOD...THE CYCLONE SHOULD EMERGE OVER THE NORTHWEST
CARIBBEAN SEA AND...ASSUMING THE CIRCULATION IS NOT TOO SEVERELY
DISRUPTED BY ITS PASSAGE OVER LAND...THE SYSTEM SHOULD RESTRENGTHEN
INTO A TROPICAL STORM.  HOWEVER...THE GLOBAL MODELS INDICATE ONLY A
MARGINALLY FAVORABLE UPPER-LEVEL WIND ENVIRONMENT OVER THE
REGION...WHICH SHOULD CURTAIL SIGNIFICANT INTENSIFICATION AS IDA
HEADS IN THE GENERAL DIRECTION OF THE YUCATAN CHANNEL.  AFTER IDA
ENTERS THE SOUTHERN GULF OF MEXICO....THE INTENSITY FORECAST IS
HIGHLY UNCERTAIN.  THE LARGE-SCALE MODELS ALL AGREE ON AN
INCREASINGLY STRONG VERTICAL SHEAR ENVIRONMENT DEVELOPING OVER THE
GULF OF MEXICO TOWARD THE END OF THE FORECAST PERIOD.  THE GFDL AND
HWRF MODELS...PARTICULARLY THE FORMER...SHOW SIGNIFICANT
INTENSIFICATION OF IDA IN THE LATTER PART OF THE PERIOD.  IT SHOULD
BE RECALLED HOWEVER THAT THESE MODELS HAVE BEEN KNOWN TO HAVE A
HIGH BIAS IN STRONGLY SHEARED ENVIRONMENTS...AS WAS THE CASE WITH
TROPICAL STORMS DANNY...ERIKA...AND HENRI OF THIS YEAR. 
CONSEQUENTLY...THE OFFICIAL WIND SPEED FORECAST LEANS MORE TOWARD
THE WEAKER LGEM AND SHIPS PREDICTIONS.

THE INITIAL MOTION IS ESTIMATED TO BE 330/4...WITHIN THE SOUTHERLY
STEERING FLOW ON THE WEST SIDE OF A WEAK MID-LEVEL RIDGE. WITH THE
EXCEPTION OF FORWARD SPEED DISPARITIES...THE GLOBAL AND REGIONAL
MODELS CONTINUE TO INDICATE A GENERAL NORTH TO NORTH-NORTHWESTWARD
MOTION INTO THE CENTRAL GULF OF MEXICO OVER THE NEXT 4 DAYS. 
AROUND THE END OF THE PERIOD...MOST OF THE TRACK GUIDANCE SHOWS A
TURN TO THE RIGHT AS IDA BEGINS TO INTERACT WITH THE WESTERLIES. 
THE OFFICIAL FORECAST HAS CHANGED LITTLE FROM THE PREVIOUS ONE AND
IS CLOSE TO THE MODEL CONSENSUS.
 
THE BIGGEST IMPACT OF THIS SLOW-MOVING SYSTEM DURING THE NEXT DAY OR
SO WILL LIKELY BE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES
CAUSED BY EXTREMELY HEAVY RAIN OVER PORTIONS OF NICARAGUA AND
HONDURAS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      06/0300Z 13.8N  84.1W    30 KT
 12HR VT     06/1200Z 14.4N  84.1W    25 KT...INLAND
 24HR VT     07/0000Z 15.4N  84.2W    25 KT...INLAND
 36HR VT     07/1200Z 16.6N  84.5W    35 KT...OVER WATER
 48HR VT     08/0000Z 17.7N  85.0W    40 KT
 72HR VT     09/0000Z 20.3N  86.2W    45 KT
 96HR VT     10/0000Z 23.0N  87.5W    45 KT
120HR VT     11/0000Z 26.0N  87.0W    45 KT
 
$$
FORECASTER PASCH/ROBERTS
 

WTNT41 KNHC 060838
TCDAT1
TROPICAL DEPRESSION IDA DISCUSSION NUMBER   8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
400 AM EST FRI NOV 06 2009
 
THE DEEP CONVECTION IS NOW LARGELY CONFINED TO THE NORTHERN
SEMICIRCLE OF THE CIRCULATION...WITH THE COLDEST TOPS FOUND IN A
BAND EXTENDING FROM EASTERN HONDURAS INTO THE NORTHWESTERN
CARIBBEAN. THE INITIAL INTENSITY IS HELD AT 30 KT FOR THIS
ADVISORY...BUT IDA WILL LIKELY WEAKEN A LITTLE MORE TODAY WHILE THE
CENTER REMAINS OVER LAND.  IT NOW APPEARS THAT THE CENTER OF IDA
WILL REMAIN EAST OF THE HIGHEST TERRAIN IN NICARAGUA AND HONDURAS
BEFORE IT EMERGES OVER THE NORTHWEST CARIBBEAN SEA IN ABOUT 24
HOURS.  IF IDA SURVIVES UNTIL THEN IT WILL HAVE AN OPPORTUNITY TO
RESTRENGTHEN.  THERE IS SIGNIFICANT SPREAD IN THE INTENSITY
GUIDANCE...WITH THE GFDL AND HWRF MODELS SHOWING IDA REACHING
HURRICANE INTENSITY AS IT ENTERS THE GULF OF MEXICO IN 3 TO 4 DAYS.
CONVERSELY...THE SHIPS MODEL SHOWS ONLY MODEST STRENGTHENING WHILE
THE LGEM SHOWS GRADUAL WEAKENING.  THE OFFICIAL FORECAST IS CLOSER
TO THE LATTER SCENARIO AS THE UPPER-LEVEL ENVIRONMENT DEPICTED BY
THE GLOBAL MODELS DOES NOT APPEAR CONDUCIVE FOR SIGNIFICANT
INTENSIFICATION ONCE IDA MOVES INTO THE GULF OF MEXICO.
 
THE INITIAL MOTION CONTINUES TO NUDGE TO THE RIGHT AND IS ESTIMATED
TO BE 350/05 AS IDA MOVES AROUND THE WESTERN PERIPHERY OF A WEAK
MID-LEVEL RIDGE OVER THE CARIBBEAN SEA.  A GENERAL NORTHWARD TO
NORTH-NORTHWESTWARD MOTION IS EXPECTED OVER THE NEXT 4 DAYS BRINGING
IDA INTO THE YUCATAN CHANNEL AND THEN INTO THE CENTRAL GULF OF
MEXICO.  BY THE END OF THE FORECAST PERIOD...THE GLOBAL MODELS SHOW
IDA INTERACTING WITH A MID- TO UPPER-LEVEL TROUGH THAT DIGS INTO
THE NORTHERN GULF OF MEXICO...AND MANY OF THE MODELS RESPOND BY
TURNING IDA NORTHEASTWARD.  THE OFFICIAL TRACK FORECAST IS
BASICALLY AN UPDATE OF THE PREVIOUS ONE AND REMAINS NEAR THE MIDDLE
OF THE GUIDANCE ENVELOPE.
 
THE BIGGEST IMPACT OF THIS IDA IN THE NEXT DAY OR SO WILL LIKELY BE
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES CAUSED BY EXTREMELY
HEAVY RAIN OVER PORTIONS OF NICARAGUA AND HONDURAS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      06/0900Z 14.4N  84.1W    30 KT
 12HR VT     06/1800Z 15.2N  84.2W    25 KT...INLAND
 24HR VT     07/0600Z 16.4N  84.4W    30 KT...OVER WATER
 36HR VT     07/1800Z 17.4N  84.8W    35 KT
 48HR VT     08/0600Z 18.7N  85.4W    40 KT
 72HR VT     09/0600Z 21.5N  86.7W    45 KT
 96HR VT     10/0600Z 24.0N  87.5W    45 KT
120HR VT     11/0600Z 27.0N  86.5W    45 KT
 
$$
FORECASTER CANGIALOSI/BRENNAN
 

WTNT41 KNHC 061453
TCDAT1
TROPICAL DEPRESSION IDA DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
1000 AM EST FRI NOV 06 2009
 
SATELLITE IMAGES INDICATE THAT BANDS OF THUNDERSTORMS CONTINUE TO
FORM IN THE NORTHERN SEMICIRCLE OF IDA...THOUGH SOMEWHAT REMOVED
FROM THE CENTER. NOAA BUOY 42057 SHOWED PEAK 1-MINUTE WINDS OF 29
KT EARLIER THIS MORNING...SO THE INITIAL INTENSITY WILL BE HELD AT
30 KT. IDA WILL HAVE AN OPPORTUNITY FOR SOME RESTRENGTHENING
OVERNIGHT AFTER IT EMERGES FROM EASTERN HONDURAS. THERE CONTINUES
TO BE A LARGE DISAGREEMENT AMONG THE MODELS ON HOW MUCH
INTENSIFICATION TO EXPECT WITH IDA. THE STATISTICAL GUIDANCE
GENERALLY SHOWS A RATHER MODEST AMOUNT OF RESTRENGTHENING...WHILE
THE REGIONAL HURRICANE MODELS SUGGEST THAT IDA WILL BECOME A
HURRICANE AGAIN. SINCE SHEAR IS FORECAST TO BE NEAR 20 KT OVER THE
NORTHWESTERN CARIBBEAN BY MOST OF THE GLOBAL MODELS...AND EVEN
HIGHER IN THE GULF OF MEXICO...THE NHC FORECAST WILL STAY MUCH
CLOSER TO THE STATISTICAL GUIDANCE. AT THE END OF PERIOD...SOME
WEAKENING IS SHOWN DUE TO SHEAR BECOMING STRONG AND COOLER WATERS
IN THE NORTHERN GULF OF MEXICO...WHICH WILL LIKELY START THE
EXTRATROPICAL TRANSITION OF IDA.
 
IDA HAS TURNED TOWARD THE NORTH...360/6. A WEAK MID-LEVEL RIDGE OVER
THE CENTRAL CARIBBEAN SEA IS FORECAST TO STEER THE STORM NORTHWARD
FOR THE NEXT DAY OR SO. THEREAFTER... IDA SHOULD TURN TOWARD THE
NORTH-NORTHWEST OR NORTHWEST AS SHORTWAVE RIDGING OVER THE
SOUTHEASTERN UNITED STATES BUILDS. IN THE LONG-RANGE...A TROUGH
OVER THE GULF OF MEXICO COULD FORCE IDA TO TURN TO THE NORTH OR
NORTHEAST. HOWEVER...THE INTERACTION OF IDA WITH THAT TROUGH IS
CAUSING A WIDE VARIETY OF MODEL SOLUTIONS... RANGING FROM A FASTER
CENTRAL GULF OF MEXICO LANDFALL TO IDA REMAINING SEPARATE FROM THE
TROUGH AND STAYING OVER THE CENTRAL GULF WATERS. ALTHOUGH SOME OF
THE MODELS HAVE SHIFTED WESTWARD SINCE THE LAST RUN...CLIMATOLOGY
AND THE FORECAST STRONG UPPER- LEVEL SOUTHWESTERLY WINDS SUGGEST
THE EASTERN SOLUTIONS ARE LIKELY CLOSER TO REALITY. THE NHC
FORECAST REMAINS CLOSE TO THE PREVIOUS ONE...AND ON THE EASTERN
SIDE OF THE GUIDANCE ENVELOPE.
 
THERE IS STILL A THREAT OF LIFE-THREATENING FLASH FLOODS AND MUD
SLIDES CAUSED BY EXTREMELY HEAVY RAIN OVER PORTIONS OF HONDURAS
TODAY.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      06/1500Z 15.0N  84.0W    30 KT
 12HR VT     07/0000Z 15.7N  84.1W    30 KT...OVER WATER
 24HR VT     07/1200Z 16.8N  84.5W    35 KT
 36HR VT     08/0000Z 17.9N  85.1W    40 KT
 48HR VT     08/1200Z 19.1N  85.8W    45 KT
 72HR VT     09/1200Z 22.5N  87.5W    45 KT
 96HR VT     10/1200Z 25.0N  87.5W    45 KT
120HR VT     11/1200Z 27.0N  86.0W    40 KT...EXTRATROPICAL
 
$$
FORECASTER BLAKE/FRANKLIN
 

WTNT41 KNHC 062045
TCDAT1
TROPICAL DEPRESSION IDA DISCUSSION NUMBER  10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
400 PM EST FRI NOV 06 2009
 
THERE HAS BEEN LITTLE CHANGE WITH IDA DURING THE DAY.  SATELLITE
IMAGES STILL SHOW A RATHER ASYMMETRIC SYSTEM...WITH MOST OF THE
SIGNIFICANT BANDING ACTIVITY TO THE NORTH OF THE CENTER.  THE
INITIAL INTENSITY WILL BE MAINTAINED AT 30 KT.  NOW THAT IDA IS
OFFSHORE OVER VERY WARM WATERS...THE SYSTEM HAS A CHANCE TO RE-
INTENSIFY.  THE BEST OPPORTUNITY FOR THE TROPICAL CYCLONE TO
STRENGTHEN IS OVER THE NORTHWESTERN CARIBBEAN SEA...WHERE VERTICAL
WIND SHEAR IS FORECAST TO BE MODERATE BY THE GLOBAL MODELS.  SHEAR
IS LIKELY TO GET RATHER STRONG BY THE TIME THE SYSTEM ENTERS THE
CENTRAL GULF OF MEXICO...WITH COOLER WATERS PRESENT...SO WEAKENING
WILL BE SHOWN AT THAT TIME.  WHILE THE DYNAMICAL GUIDANCE REMAINS
HIGHER THAN THE STATISTICAL GUIDANCE...THERE IS A LITTLE LESS
SPREAD THAN EARLIER.  THE NHC FORECAST SHOWS SLIGHTLY HIGHER WINDS
IN THE CARIBBEAN SEA THAN THE PREVIOUS FORECAST DID...AND REDUCES
THE INTENSITY AT THE END OF THE FORECAST PERIOD. 

IDA CONTINUES MOVING TOWARD THE NORTH...360/7.  THE DEPRESSION
SHOULD MOVE TOWARD THE NORTH-NORTHWEST TOMORROW DUE TO SHORTWAVE
RIDGING OVER THE SOUTHEASTERN UNITED STATES.  MOST OF THE MODELS
ARE IN GOOD AGREEMENT ON THE SYSTEM PASSING OVER OR JUST TO THE
EAST OF THE YUCATAN PENINSULA IN A COUPLE OF DAYS.  AFTER IDA
ENTERS THE GULF OF MEXICO...IT WILL LIKELY TAKE A TRACK TOWARD THE
NORTH OR NORTHEAST AS IT BECOMES STEERED BY AN APPROACHING
MID-LEVEL TROUGH.  THE FORECAST TRACK IS VERY COMPLEX IN THE LONG
RANGE WITH SIGNIFICANT UNCERTAINTY IN HOW IDA WILL INTERACT WITH
THAT TROUGH.  MOST OF THE MODELS ARE SHOWING THE CYCLONE
APPROACHING THE NORTHERN GULF COAST...THEN TURNING EASTWARD OR EVEN
SOUTH OF EAST.  A COMPLICATING FACTOR IS THAT IDA WILL LIKELY BE
TRANSITIONING INTO AN EXTRATROPICAL CYCLONE AT THAT TIME...AND THE
GLOBAL MODELS HAVE QUITE VARYING SOLUTIONS FOR THIS TRANSITION. 
THE NHC FORECAST IS ADJUSTED NORTHWARD AT THE LONG RANGE...BUT
REMAINS SOUTH OF THE MODEL CONSENSUS.  

IT IS OF NOTE THAT MOST OF THE GLOBAL MODELS ARE SHOWING A LARGE
PRESSURE GRADIENT BETWEEN A HIGH OVER THE SOUTHEASTERN UNITED
STATES AND THE TROPICAL CYCLONE.  THIS COULD CONTRIBUTE TO A LARGE
AREA OF STRONG WINDS OVER THE GULF OF MEXICO NOT DIRECTLY
ATTRIBUTABLE TO IDA.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      06/2100Z 15.7N  83.9W    30 KT
 12HR VT     07/0600Z 16.7N  84.1W    30 KT
 24HR VT     07/1800Z 17.9N  84.7W    35 KT
 36HR VT     08/0600Z 19.1N  85.4W    45 KT
 48HR VT     08/1800Z 20.6N  86.3W    50 KT
 72HR VT     09/1800Z 24.5N  88.0W    45 KT
 96HR VT     10/1800Z 27.5N  87.5W    45 KT
120HR VT     11/1800Z 27.5N  85.5W    35 KT...EXTRATROPICAL
 
$$
FORECASTER BLAKE
 

WTNT41 KNHC 070233
TCDAT1
TROPICAL DEPRESSION IDA DISCUSSION NUMBER  11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
1000 PM EST FRI NOV 06 2009
 
A 2302 UTC SSMIS MICROWAVE PASS INDICATED THAT THE LOW-LEVEL CENTER
OF IDA WAS LOCATED JUST OFF THE NORTHEASTERN COAST OF HONDURAS AND
WAS DISPLACED TO THE SOUTH AND SOUTHEAST OF THE DEEP CONVECTION.
NEW CONVECTION IS DEVELOPING CLOSE TO THE CENTER...AND DVORAK
ESTIMATES FROM TAFB AND SAB ARE 25 KT AND 30 KT...RESPECTIVELY.
NOAA BUOY 42057...LOCATED ABOUT 150 N MI EAST-NORTHEAST OF THE
CENTER...RECENTLY REPORTED A 1-MINUTE SUSTAINED WIND OF 35 KT...BUT
IT APPEARS THAT THIS OCCURRED WITH THE PASSAGE OF A SQUALL AND MAY
NOT BE REPRESENTATIVE OF THE OVERALL CIRCULATION.  THEREFORE...IDA
IS KEPT AS A TROPICAL DEPRESSION FOR THIS ADVISORY...BUT IT IS
PROBABLY VERY CLOSE TO REGAINING TROPICAL STORM STATUS.
 
IDA CONTINUES TO MOVE NORTHWARD AT 360/6.  A MID-LEVEL ANTICYCLONE
BETWEEN JAMAICA AND HISPANIOLA AND A DEEP-LAYER TROUGH OVER MEXICO
ARE EXPECTED TO STEER IDA NORTH-NORTHWESTWARD THROUGH THE NEXT 72
HOURS.  THE TRACK GUIDANCE IS IN GOOD AGREEMENT DURING THIS PERIOD
ALTHOUGH THE GFDL AND HWRF MODELS ARE THE EASTERNMOST MODELS AND
HAVE FORCED THE MODEL CONSENSUS A LITTLE MORE TO THE EAST.  THE
FORECAST BEYOND 72 HOURS IS STILL COMPLEX AND IS DEPENDENT ON HOW
IDA INTERACTS WITH THE FRONT AND SHORTWAVE TROUGH OVER THE GULF OF
MEXICO.  MOST OF THE GUIDANCE SHOWS IDA BECOMING EXTRATROPICAL BY
96 HOURS ONCE IT MERGES WITH THE FRONT...BUT THE SOLUTIONS VARY ON
WHERE THE LOW GOES NEXT.  ONLY THE 1200 UTC ECMWF AND UKMET SHOW
IDA BECOMING PICKED UP BY A SHORTWAVE TROUGH AND MOVING
NORTHEASTWARD OVER THE NORTHERN GULF.  THE OTHER MODELS INDICATE A
MORE PRONOUNCED SOUTHWARD MOTION AFTER 96 HOURS...AND THE OFFICIAL
FORECAST NOW SHOWS A SLOW SOUTHEASTWARD TURN AT 120 HOURS.
 
ALTHOUGH WATERS ARE WARM OVER THE NORTHWESTERN CARIBBEAN...VERTICAL
SHEAR IS EXPECTED TO HAMPER MUCH INTENSIFICATION OVER THE NEXT FEW
DAYS.  THE GFDL AND HWRF MAKE IDA A HURRICANE OVER THE CENTRAL GULF
OF MEXICO...A SCENARIO THAT DOES NOT SEEM PLAUSIBLE IN THE FACE OF
WESTERLY SHEAR THAT IS EXPECTED TO INCREASE TO 50 OR 60 KT BY DAY
4.  THE OFFICIAL FORECAST INDICATES SOME SLOW STRENGTHENING OVER
THE NEXT SEVERAL DAYS BUT PEAKS THE INTENSITY AT 45 KT...WHICH IS
JUST BELOW THE INTENSITY CONSENSUS.
 
IT IS OF NOTE THAT MOST OF THE GLOBAL MODELS ARE SHOWING A LARGE
PRESSURE GRADIENT BETWEEN A HIGH OVER THE SOUTHEASTERN UNITED
STATES AND THE TROPICAL CYCLONE.  THIS COULD CONTRIBUTE TO A LARGE
AREA OF STRONG WINDS OVER THE GULF OF MEXICO NOT DIRECTLY
ATTRIBUTABLE TO IDA.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      07/0300Z 16.2N  84.0W    30 KT
 12HR VT     07/1200Z 17.1N  84.2W    35 KT
 24HR VT     08/0000Z 18.4N  84.8W    35 KT
 36HR VT     08/1200Z 19.7N  85.5W    40 KT
 48HR VT     09/0000Z 21.4N  86.5W    45 KT
 72HR VT     10/0000Z 25.5N  88.0W    45 KT
 96HR VT     11/0000Z 27.5N  87.0W    45 KT...EXTRATROPICAL
120HR VT     12/0000Z 26.5N  85.6W    35 KT...EXTRATROPICAL
 
$$
FORECASTER BERG
 

WTNT41 KNHC 070857
TCDAT1
TROPICAL STORM IDA DISCUSSION NUMBER  12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
400 AM EST SAT NOV 07 2009
 
THE SATELLITE PRESENTATION OF IDA HAS IMPROVED OVER THE PAST SEVERAL
HOURS...WITH AN INCREASE IN DEEP CONVECTION NEAR THE ESTIMATED
LOCATION OF THE LOW LEVEL CENTER.  THE INITIAL INTENSITY IS RAISED
TO 40 KT BASED ON A BLEND OF DVORAK ESTIMATES OF 35 KT FROM SAB AND
45 KT FROM TAFB.  
 
THE INITIAL MOTION ESTIMATE IS 350/07...A LITTLE FASTER THAN BEFORE.
IDA IS MOVING NORTHWARD BETWEEN A MID-LEVEL ANTICYCLONE OVER THE
NORTH-CENTRAL CARIBBEAN SEA AND A DEEP-LAYER TROUGH OVER SOUTHERN
MEXICO. MOST OF THE TRACK GUIDANCE IS TIGHTLY CLUSTERED THROUGH 48
HOURS...AND THE OFFICIAL FORECAST THROUGH THAT TIME IS CLOSE TO THE
MODEL CONSENSUS BUT A LITTLE FASTER THAN THE PREVIOUS PACKAGE.
BEYOND 48 HOURS...THE GLOBAL MODELS SHOW A MID- TO UPPER-LEVEL
SHORTWAVE TROUGH DIGGING INTO THE NORTHERN GULF OF MEXICO. WHILE
THE DETAILS ON THE TIMING AND DEGREE OF THE INTERACTION BETWEEN IDA
AND THE TROUGH DIFFER...MOST OF THE MODELS...WITH THE EXCEPTION OF
THE NOGAPS AND GFDN...SHOW IDA TURNING NORTHWARD AND THEN
NORTHEASTWARD IN 3 OR 4 DAYS.  IDA IS EXPECTED TO BECOME
EXTRATROPICAL DURING THIS TIME AS IT BECOMES INVOLVED WITH A
LOW-LEVEL FRONTAL ZONE ALONG THE NORTHERN GULF COAST.  BY DAY 5
MOST OF THE GUIDANCE SHOWS THE FRONT...AND WHAT IS LEFT OF IDA...
TURNING SOUTHWARD OR SOUTHEASTWARD IN RESPONSE TO A LARGE SCALE MID-
TO UPPER-LEVEL TROUGH AMPLIFYING OVER EASTERN NORTH AMERICA.  AT
DAYS 3 THROUGH 5 THE NEW OFFICIAL THE FORECAST IS ADJUSTED A LITTLE
NORTHWARD TOWARD THE MODEL CONSENSUS.
 
WHILE IDA WILL BE MOVING OVER VERY WARM WATERS FOR THE NEXT COUPLE
OF DAYS THE ENVIRONMENT WILL NOT BE IDEAL FOR STRENGTHENING...AS
THE SHIPS MODEL SHOWS ABOUT 20 KT OF VERTICAL SHEAR OVER THE
CYCLONE. BEYOND THAT TIME...THE SHEAR IS FORECAST TO INCREASE
FURTHER AS IDA BEGINS TO INTERACT WITH THE MID- TO UPPER-LEVEL
SHORTWAVE.  THE OFFICIAL FORECAST IS ADJUSTED UPWARD A LITTLE GIVEN
THE OBSERVED INTENSITY TRENDS...AND SHOWS A PEAK OF 50 KT IN 36
HOURS. THIS IS IN BEST AGREEMENT WITH THE SHIPS MODEL AND CLOSE TO
THE ICON INTENSITY CONSENSUS.  GRADUAL WEAKENING IS EXPECTED TO
BEGIN ON DAY 2 AS IDA ENCOUNTERS THE STRONGER SHEAR AND BEGINS TO
UNDERGO EXTRATROPICAL TRANSITION.

MOST OF THE GLOBAL MODELS SHOW A LARGE PRESSURE GRADIENT DEVELOPING
BETWEEN A HIGH PRESSURE RIDGE OVER THE SOUTHEASTERN UNITED STATES
AND THE TROPICAL CYCLONE.  THIS WILL CONTRIBUTE TO A LARGE AREA OF
STRONG WINDS OVER THE GULF OF MEXICO NOT DIRECTLY ATTRIBUTABLE TO
IDA.
 
THE ISSUANCE OF A TROPICAL STORM WATCH IS REQUIRED AT THIS TIME FOR
PORTIONS OF THE YUCATAN PENINSULA AND WESTERN CUBA.  

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      07/0900Z 17.1N  84.1W    40 KT
 12HR VT     07/1800Z 18.1N  84.4W    45 KT
 24HR VT     08/0600Z 19.5N  85.0W    45 KT
 36HR VT     08/1800Z 21.0N  86.0W    50 KT
 48HR VT     09/0600Z 23.0N  87.1W    45 KT
 72HR VT     10/0600Z 26.5N  88.0W    45 KT
 96HR VT     11/0600Z 28.0N  86.5W    40 KT...EXTRATROPICAL
120HR VT     12/0600Z 27.0N  85.0W    35 KT...EXTRATROPICAL
 
$$
FORECASTER BRENNAN
 

WTNT41 KNHC 071500
TCDAT1
TROPICAL STORM IDA DISCUSSION NUMBER  13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
1000 AM EST SAT NOV 07 2009
 
RECENT MICROWAVE IMAGERY SUGGESTS THAT THE STRUCTURE OF
IDA HAS CONTINUED TO IMPROVE THIS MORNING...WITH A COUPLE OF
HOOKING BANDS NEAR THE CENTER.  VISIBLE IMAGERY SHOWS AN EXPANDING
CENTRAL DENSE OVERCAST FEATURE AND NO OBVIOUS SIGNS OF SIGNIFICANT
SHEAR.  THE LATEST DVORAK INTENSITY ESTIMATES ARE 45 KT FROM BOTH
AGENCIES...BUT GIVEN THE INCREASE IN ORGANIZATION SINCE THAT TIME
THE INITIAL INTENSITY HAS BEEN RAISED TO 50 KT.  AN AIR FORCE
RESERVE HURRICANE HUNTER AIRCRAFT IS CURRENTLY EN ROUTE TO
INVESTIGATE THE STORM.
 
IDA IS MOVING NORTHWARD OR 355/8.  IDA IS EXPECTED TO MOVE
NORTH-NORTHWESTWARD BETWEEN A MID-LEVEL ANTICYCLONE OVER THE
NORTH-CENTRAL CARIBBEAN SEA AND A DEEP-LAYER TROUGH OVER SOUTHERN
MEXICO. THE TRACK GUIDANCE IS IN GOOD AGREEMENT THROUGH 36 TO 48
HOURS AND THE NHC FORECAST REMAINS IN LINE WITH THE MODEL CONSENSUS
DURING THAT TIME.  THEREAFTER...THERE IS A LARGE SPREAD AMONG THE
MODELS AS TO HOW IDA INTERACTS WITH A MID- TO UPPER-LEVEL TROUGH
DIGGING INTO THE NORTHERN GULF OF MEXICO.  THE GFS...ECMWF...AND
HWRF ALL MOVE THE CYCLONE QUICKLY NORTHWARD AND SHOW IT REACHING
THE NORTHERN GULF COAST IN ABOUT 3 DAYS AS IT BECOMES AN
EXTRATROPICAL CYCLONE.  THE REMAINDER OF THE GUIDANCE HAS TRENDED
NORTHWARD...BUT TURNS THE SYSTEM GENERALLY EASTWARD BEFORE REACHING
THE NORTHERN GULF COAST.  FOR NOW...THE OFFICIAL FORECAST IS
BETWEEN THESE TWO SCENARIOS...BUT HAS BEEN ADJUSTED NORTHWARD TO
ACCOUNT FOR THE LATEST TRENDS.
 
ENVIRONMENTAL CONDITIONS...WHILE NOT IDEAL...APPEAR CONDUCIVE ENOUGH
FOR STRENGTHENING DURING THE NEXT DAY OR SO AS THE CYCLONE
TRAVERSES THE NORTHWEST CARIBBEAN SEA.  THE OFFICIAL FORECAST HAS
BEEN ADJUSTED UPWARD FROM THE PREVIOUS ONE BASED ON RECENT TRENDS. 
ONCE IDA REACHES THE GULF OF MEXICO...SHEAR IS FORECAST TO INCREASE
AND WATERS BEGIN TO COOL. THESE FACTORS SHOULD CONTRIBUTE TO
WEAKENING...HOWEVER THE INTERACTION WITH THE UPPER-TROUGH AND AN
EXPECTED EXTRATROPICAL TRANSITION WILL LIKELY RESULT IN LESS
WEAKENING THAN TYPICAL...GIVEN THE STRONG SHEAR.
 
MOST OF THE GLOBAL MODELS SHOW A LARGE PRESSURE GRADIENT BETWEEN
A HIGH PRESSURE RIDGE OVER THE SOUTHEASTERN UNITED STATES AND THE
TROPICAL CYCLONE.  THIS IS ALREADY CONTRIBUTING TO A LARGE AREA OF
STRONG WINDS OVER THE SOUTHERN GULF OF MEXICO WHICH IS NOT DIRECTLY
ATTRIBUTABLE TO IDA.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      07/1500Z 17.9N  84.1W    50 KT
 12HR VT     08/0000Z 18.9N  84.6W    55 KT
 24HR VT     08/1200Z 20.3N  85.5W    60 KT
 36HR VT     09/0000Z 22.2N  86.8W    55 KT
 48HR VT     09/1200Z 24.6N  88.0W    45 KT
 72HR VT     10/1200Z 28.5N  88.0W    45 KT...EXTRATROPICAL
 96HR VT     11/1200Z 29.0N  86.5W    40 KT...EXTRATROPICAL
120HR VT     12/1200Z 28.0N  85.0W    35 KT...EXTRATROPICAL
 
$$
FORECASTER BROWN/CANGIALOSI/BLAKE
 

WTNT41 KNHC 072056
TCDAT1
TROPICAL STORM IDA DISCUSSION NUMBER  14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
400 PM EST SAT NOV 07 2009
 
THE SATELLITE APPEARANCE OF IDA HAS NOT CHANGED SIGNIFICANTLY THIS
AFTERNOON.  THE AIRCRAFT FOUND THE CENTER A LITTLE NORTH OF THE
EARLIER ESTIMATES...WELL EMBEDDED WITHIN THE CENTRAL DENSE
OVERCAST.  THE PLANE MEASURED A PEAK 850 MB FLIGHT-LEVEL WIND OF 68
KT AND A SFMR SURFACE WIND OF 60 KT. THESE DATA SUPPORT AN INITIAL
INTENSITY OF 60 KT.  CIRRUS ELEMENTS ARE MOVING NORTHEASTWARD...
SUGGESTING MODERATE SOUTHWESTERLY UPPER-LEVEL FLOW OVER THE
CYCLONE.  HOWEVER IT DOES NOT APPEAR THAT SHEAR WILL BE STRONG
ENOUGH IN THE SHORT-TERM TO INHIBIT SOME ADDITIONAL
INTENSIFICATION.  IDA WILL BE TRAVERSING THE VERY WARM WATER OF THE
NORTHWESTERN CARIBBEAN SEA AND THE INTENSITY GUIDANCE NOW
UNANIMOUSLY PREDICTS IDA TO BECOME A HURRICANE WITHIN 12
HOURS...AND THE OFFICIAL FORECAST FOLLOWS SUIT.  AFTER IDA REACHES
THE GULF OF MEXICO...THE SHEAR IS FORECAST TO INCREASE AND WATERS
BEGIN TO COOL. THESE FACTORS SHOULD CONTRIBUTE TO MORE STEADY
WEAKENING.
 
IDA HAS BEEN MOVING NORTHWARD AT A SLIGHTLY FASTER FORWARD SPEED
TODAY.  THE TRACK GUIDANCE IS TIGHTLY CLUSTERED ON A NORTH-
NORTHWESTWARD MOTION DURING THE NEXT 24 TO 36 HOURS.  THE OFFICIAL
FORECAST DURING THIS PERIOD REMAINS NEAR THE MODEL CONSENSUS BUT HAS
BEEN ADJUSTED A LITTLE EASTWARD PRIMARILY DUE TO THE MORE NORTHWARD
INITIAL POSITION AND HEADING.  THEREAFTER...THERE REMAINS
SIGNIFICANT DIFFERENCES IN THE GUIDANCE AS TO HOW IDA INTERACTS
WITH A MID- TO UPPER-LEVEL TROUGH THAT MOVES INTO THE NORTHWESTERN
GULF OF MEXICO IN A COUPLE OF DAYS.  THE 12Z GFS...ECMWF...AND HWRF
CONTINUE TO SHOW THE CYCLONE REACHING THE NORTHERN GULF COAST IN
ABOUT 72 HOURS AS IT BECOMES AN EXTRATROPICAL CYCLONE.  THE
OFFICIAL FORECAST IS A LITTLE FASTER THAN THE PREVIOUS ONE...AND
HAS ONCE AGAIN BEEN SHIFTED NORTHWARD.  THE NEW TRACK NOW SHOWS A
POSITION JUST SOUTH OF THE NORTHERN GULF COAST IN 3 DAYS.
THEREAFTER...MOST OF THE GUIDANCE TURNS THE CYCLONE EASTWARD...AND
SO DOES THE OFFICIAL FORECAST.  BY 120 HOURS...SOME OF THE GUIDANCE
SUGGEST THAT THE LOW WILL BE ABSORBED BY A FRONTAL BOUNDARY...AND
THE OFFICIAL FORECAST DOES NOT PROVIDE A 5-DAY POSITION FOR THIS
REASON.
 
MOST OF THE GLOBAL MODELS SHOW A LARGE PRESSURE GRADIENT BETWEEN
A HIGH PRESSURE RIDGE OVER THE SOUTHEASTERN UNITED STATES AND THE
TROPICAL CYCLONE.  THIS IS ALREADY CONTRIBUTING TO A LARGE AREA OF
STRONG WINDS OVER THE SOUTHERN GULF OF MEXICO WHICH IS NOT DIRECTLY
ATTRIBUTABLE TO IDA.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      07/2100Z 18.9N  84.3W    60 KT
 12HR VT     08/0600Z 20.1N  84.8W    75 KT
 24HR VT     08/1800Z 21.6N  85.8W    70 KT
 36HR VT     09/0600Z 23.8N  87.2W    60 KT
 48HR VT     09/1800Z 26.3N  88.0W    50 KT
 72HR VT     10/1800Z 29.5N  87.3W    45 KT...EXTRATROPICAL
 96HR VT     11/1800Z 29.5N  86.0W    40 KT...EXTRATROPICAL
120HR VT     12/1800Z...DISSIPATED
 
$$
FORECASTER BROWN
 

WTNT41 KNHC 080246
TCDAT1
TROPICAL STORM IDA DISCUSSION NUMBER  15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
1000 PM EST SAT NOV 07 2009
 
THERE HAS BEEN LITTLE CHANGE TO THE SATELLITE APPEARANCE OF IDA
SINCE THE AIR FORCE PLANE LEFT EARLIER THIS AFTERNOON.  THE
LOW-LEVEL CENTER IS STILL EMBEDDED WITHIN A LARGE CENTRAL DENSE
OVERCAST ALTHOUGH RECENT MICROWAVE DATA SUGGEST THAT THE SYSTEM IS
BEING IMPACTED BY SOME SOUTHERLY SHEAR.  THE INTENSITY WILL BE HELD
AT 60 KT FOR THIS ADVISORY...WHICH IS SUPPORTED BY DVORAK ESTIMATES
OF 55 KT FROM BOTH TAFB AND SAB AND AN OBJECTIVE ADT ESTIMATE OF 61
KT.  ANOTHER AIR FORCE RECONNAISSANCE AIRCRAFT IS SCHEDULED TO
INVESTIGATE IDA IN A FEW HOURS TO PROVIDE UPDATED INFORMATION.

IDA HAS TURNED TO THE NORTH-NORTHWEST WITH AN INITIAL MOTION OF 340
DEGREES AT 10 KT AS IT IS STEERED BETWEEN AN AMPLIFIED TROUGH OVER
MEXICO AND A MID-LEVEL RIDGE THAT EXTENDS FROM THE SOUTHEASTERN
U.S. TO HISPANIOLA.  THE TRACK GUIDANCE IS IN EXCELLENT AGREEMENT
THROUGH 48 HOURS ON A CONTINUED NORTH-NORTHWESTWARD MOTION...AND
THE NEW OFFICIAL FORECAST IS ONLY SLIGHTLY TO THE EAST OF THE
PREVIOUS FORECAST.  THEREAFTER...ALL THE MODELS BRING IDA TO THE
COAST NEAR THE FLORIDA PANHANDLE AS AN EXTRATROPICAL CYCLONE BUT
QUICKLY TURN IT TO THE SOUTHEAST AS THE ABSORBING COLD FRONT
PUSHES SOUTHWARD OVER THE GULF.

ALTHOUGH SOME SHEAR IS AFFECTING IDA...IT IS NOT PROHIBITIVELY
STRONG.  STRONG UPPER-LEVEL WINDS NORTH OF THE SYSTEM ARE PROVIDING
SOME DIFFLUENCE ALOFT...AND THIS WILL CONTINUE TO GIVE IDA A 24-36
HOUR WINDOW TO STRENGTHEN TO A HURRICANE.  THE SHEAR IS EXPECTED TO
INCREASE AFTER 36 HOURS AND SHOULD LEAD TO SOME WEAKENING...BUT THE
NEW INTENSITY GUIDANCE INDICATES THAT THIS WEAKENING COULD BE
SLOWER TO OCCUR THAN PREVIOUSLY FORECAST.  IDA SHOULD BEGIN THE
EXTRATROPICAL TRANSITION PROCESS AROUND 48 HOURS AND BE FULLY
EXTRATROPICAL BY 72 HOURS.
 
A TIGHT PRESSURE GRADIENT BETWEEN IDA AND HIGH PRESSURE LOCATED OVER
THE SOUTHEASTERN UNITED STATES IS ALREADY PRODUCING STRONG WINDS
OVER THE SOUTHEASTERN GULF OF MEXICO...BUT THESE WINDS ARE NOT
DIRECTLY ATTRIBUTABLE TO THE CIRCULATION OF IDA. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      08/0300Z 20.1N  84.6W    60 KT
 12HR VT     08/1200Z 21.2N  85.3W    70 KT
 24HR VT     09/0000Z 23.0N  86.5W    70 KT
 36HR VT     09/1200Z 25.4N  87.6W    65 KT
 48HR VT     10/0000Z 27.7N  87.9W    60 KT
 72HR VT     11/0000Z 30.0N  86.5W    45 KT...EXTRATROPICAL
 96HR VT     12/0000Z 29.0N  85.5W    35 KT...EXTRATROPICAL
120HR VT     13/0000Z...ABSORBED BY FRONT
 
$$
FORECASTER BERG/FRANKLIN
 

WTNT41 KNHC 080713
TCDAT1
HURRICANE IDA SPECIAL DISCUSSION NUMBER  16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
115 AM CST SUN NOV 08 2009
 
THIS SPECIAL ADVISORY IS BEING ISSUED TO ADJUST THE SHORT-TERM
INTENSITY AND TRACK FORECAST OF IDA. BASED ON THE OBSERVED 
INTENSIFICATION OF THE SYSTEM IN THE LAST FEW HOURS...THE INTENSITY
FORECAST IS RAISED TO 85 KT AT 12 AND 24 HOURS...WITH THE
POSSIBILITY THAT IDA COULD GET A LITTLE STRONGER THAN THAT SOMETIME
TODAY.  BEYOND 36 HOURS...THE INTENSITY FORECAST IS UNCHANGED FROM
THE PREVIOUS ADVISORY. 

BASED ON THE AIRCRAFT RECONNAISSANCE FIX AROUND 0600 UTC...WHICH WAS
ABOUT A HALF A DEGREE TO THE WEST OF THE FORECAST TRACK...THE TRACK
FORECAST HAS BEEN ADJUSTED WESTWARD THROUGH 24 HOURS...INCREASING
THE LIKELIHOOD THAT HURRICANE-FORCE WINDS COULD IMPACT THE
NORTHEASTERN YUCATAN PENINSULA.  THIS NECESSITATES THE ISSUANCE OF
A HURRICANE WARNING FOR A PORTION OF THE YUCATAN PENINSULA AT THIS
TIME. 

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      08/0715Z 20.2N  85.4W    80 KT
 12HR VT     08/1200Z 21.1N  85.7W    85 KT
 24HR VT     09/0000Z 22.8N  87.1W    85 KT
 36HR VT     09/1200Z 25.4N  87.6W    75 KT
 48HR VT     10/0000Z 27.7N  87.9W    60 KT
 72HR VT     11/0000Z 30.0N  86.5W    45 KT...EXTRATROPICAL
 96HR VT     12/0000Z 29.0N  85.5W    35 KT...EXTRATROPICAL
120HR VT     13/0000Z...DISSIPATED
 
$$
FORECASTER BRENNAN/KIMBERLAIN
 

WTNT41 KNHC 080900
TCDAT1
HURRICANE IDA DISCUSSION NUMBER  17
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
300 AM CST SUN NOV 08 2009
 
DATA FROM THE AIR FORCE HURRICANE HUNTER AIRCRAFT SUGGEST THAT THE
INTENSIFICATION OF IDA HAS HALTED...AT LEAST TEMPORARILY. THE
LATEST PRESSURE MEASURED ON A PASS THROUGH THE CENTER WAS 984
MB...AND THE INITIAL INTENSITY IS HELD AT 80 KT FOR THIS ADVISORY.
THE INTENSITY FORECAST SHOWS SOME STRENGTHENING IN THE SHORT
TERM...AS IDA WILL REMAIN OVER VERY WARM WATERS THROUGH THE NEXT 24
HOURS. BEYOND THAT TIME...IDA WILL BEGIN TO MOVE OVER MUCH COOLER
WATERS...BELOW 26C AFTER 48 HOURS...AND VERTICAL SHEAR WILL
INCREASE MARKEDLY AS STRONG UPPER-LEVEL SOUTHWESTERLY FLOW AHEAD OF
A MID- TO UPPER-LEVEL TROUGH IMPINGES ON IDA. GLOBAL MODEL GUIDANCE
SHOWS IDA UNDERGOING EXTRATROPICAL TRANSITION IN THE 48 TO 72 HOUR
TIME FRAME AS IT INTERACTS WITH THE TROUGH AND A SURFACE FRONT
ALONG THE NORTHERN GULF COAST. THE OFFICIAL FORECAST SHOWS GRADUAL
WEAKENING FROM 24 TO 48 HOURS...AND MORE RAPID WEAKENING AS IDA
BECOMES EXTRATROPICAL.
 
THE INITIAL MOTION ESTIMATE IS NORTHWEST...OR 325/10. THIS IS TO THE
LEFT OF THE PREVIOUS PACKAGE...AS THE FLOW AROUND A MID- TO
UPPER-LEVEL TROUGH OVER SOUTHERN MEXICO AND GUATEMALA MAY BE
TUGGING IDA A LITTLE MORE TOWARD THE WEST. THE TRACK GUIDANCE IS IN
GOOD AGREEMENT ON A TURN TOWARD THE NORTH-NORTHWEST AND THE NORTH
OVER THE NEXT 48 HOURS AS IDA ACCELERATES AHEAD OF THE TROUGH THAT
MOVES INTO THE NORTHERN GULF. GIVEN THE MORE WESTERLY COMPONENT OF
THE INITIAL MOTION...THE TRACK GUIDANCE HAS SHIFTED WESTWARD
COMPARED TO THE LAST PACKAGE...AND SO HAS THE OFFICIAL FORECAST...
WHICH NOW TAKES THE CENTER OF IDA VERY CLOSE TO THE NORTHEASTERN TIP
OF THE YUCATAN PENINSULA TODAY. IDA WILL THEN MOVE INTO THE GULF OF
MEXICO AND APPROACH THE EAST-CENTRAL GULF COAST IN 48 TO 72 HOURS.
MOST OF THE TRACK GUIDANCE SHOWS A TURN TOWARD THE EAST AND
SOUTHEAST AT DAYS 3 AND 4 AS IDA BECOMES EXTRATROPICAL. HOWEVER...
THERE IS LARGE SPREAD IN THE GUIDANCE WITH REGARD TO THE ULTIMATE
FATE OF IDA. FOR EXAMPLE...THE ECMWF SHOWS THE EXTRATROPICAL
REMNANTS OF IDA CONTINUING ACROSS THE SOUTHEASTERN UNITED
STATES...WHILE THE GFS LEAVES THE REMNANTS OF IDA BEHIND A STRONGER
BAROCLINIC LOW THAT FORMS OVER THE SOUTHEASTERN UNITED STATES.  
GIVEN THE LARGE RANGE OF POSSIBLE SOLUTIONS...THE OFFICIAL FORECAST
SHOWS A SLOW SOUTHEASTWARD MOTION AT DAY 4...AND HAS IDA
DISSIPATING AS IT IS ABSORBED INTO A FRONTAL ZONE BY DAY 5. THERE
IS A HIGH DEGREE OF UNCERTAINTY IN THIS PART OF THE FORECAST
SCENARIO.

THE OFFICIAL FORECAST SHOWS TROPICAL STORM FORCE WINDS REACHING
PORTIONS OF THE U.S. GULF COAST IN A COUPLE OF DAYS.  HOWEVER...
SINCE IDA IS EXPECTED TO BEGIN UNDERGOING EXTRATROPICAL TRANSITION
AROUND THAT TIME...THESE HAZARDS ARE BEING HANDLED BY LOCAL
NATIONAL WEATHER SERVICE OFFICES ALONG THE GULF COAST IN THEIR
PRODUCT SUITE WITH MARINE AND COASTAL FLOOD WATCHES... WARNINGS
...AND ADVISORIES.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      08/0900Z 20.5N  85.6W    80 KT
 12HR VT     08/1800Z 21.8N  86.7W    85 KT
 24HR VT     09/0600Z 24.0N  87.8W    85 KT
 36HR VT     09/1800Z 26.7N  88.5W    80 KT
 48HR VT     10/0600Z 28.5N  88.2W    65 KT
 72HR VT     11/0600Z 29.8N  86.1W    45 KT...EXTRATROPICAL
 96HR VT     12/0600Z 28.0N  84.0W    30 KT...EXTRATROPICAL
120HR VT     13/0600Z...DISSIPATED
 
$$
FORECASTER BRENNAN/KIMBERLAIN
 

WTNT41 KNHC 081516
TCDAT1
HURRICANE IDA DISCUSSION NUMBER  18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
900 AM CST SUN NOV 08 2009

THE LAST PASS OF AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT NEAR
1100 UTC SHOWED A CENTRAL PRESSURE OF 983 MB AND AN ELLIPTICAL EYE. 
SATELLITE IMAGERY AND RADAR DATA FROM CUBA AND MEXICO SINCE THAT
TIME SUGGEST LITTLE CHANGE HAS OCCURRED IN THE STRUCTURE.  BASED ON
THIS AND SATELLITE INTENSITY ESTIMATES OF 90 AND 77 KT FROM TAFB
AND SAB...THE INITIAL INTENSITY REMAINS 80 KT.  ANALYSES FROM CIMSS
AT THE UNIVERSITY OF WISCONSIN INDICATE THAT THE HURRICANE IS
CURRENTLY EXPERIENCING ABOUT 20 KT OF SOUTHWESTERLY VERTICAL WIND
SHEAR.

THE INITIAL MOTION IS 325/9.  IDA REMAINS BETWEEN A MID/UPPER-LEVEL
TROUGH OVER THE WESTERN GULF MEXICO AND ADJACENT LAND AREAS AND AN
MID/UPPER-LEVEL RIDGE OVER THE EASTERN GULF OF MEXICO AND THE
NORTHERN CARIBBEAN SEA.  IN ADDITION...A STRONG LOW-LEVEL RIDGE
COVERS THE NORTHERN GULF OF MEXICO.  THE DYNAMICAL MODELS FORECAST
THE TROUGH AND RIDGE TO MOVE EASTWARD...ALLOWING IDA TO TURN TOWARD
THE NORTH DURING THE NEXT 36 HR OR SO.  THE GFDL...HWRF...GFS...
ECMWF...AND CANADIAN MODELS ARE NOW FORECASTING A FASTER NORTHWARD
MOTION...WITH THE CENTER OF IDA REACHING THE NORTHERN GULF COAST IN
36-48 HR.  THE UKMET AND NOGAPS MODELS CONTINUE TO SHOW A SLOWER
FORWARD SPEED.  THE NEW FORECAST TRACK IS FASTER THAN THE PREVIOUS
TRACK THROUGH 48 HR...ALTHOUGH IT IS SLOWER THAN THE GFDL AND ITS
COLLEAGUES.  THE FASTER NORTHWARD MOTION ALSO RESULTS IN A MORE
NORTHERLY POSITION FOR THE LATER PART OF THE FORECAST TRACK...SO
THE 72-96 HR POSITIONS HAVE BEEN ADJUSTED NORTHWARD AS WELL.

SOME STRENGTHENING IS POSSIBLE TODAY.  AFTER THAT...IDA WILL BE
MOVING OVER COOLER SEA SURFACE TEMPERATURES...INTO A COOLER AIR
MASS...AND INTO STRONGER SHEAR.  THE DYNAMICAL MODELS AGREE THAT
EXTRATROPICAL TRANSITION SHOULD BEGIN BY ABOUT 24 HOURS AND IS
LIKELY TO BE COMPLETE IN ABOUT 48 HR.  HOWEVER...THE INTENSITY
GUIDANCE FORECASTS HURRICANE-FORCE WINDS THROUGH 48 HR...SO THE
INTENSITY FORECAST MAINTAINS HURRICANE STRENGTH THROUGH THAT TIME.
IN THE 72-120 HR TIME FRAME...THE GFS...ECMWF...AND CANADIAN MODELS
FORECAST A LARGE BAROCLINIC LOW OFF THE U. S. EAST COAST.  IT IS
NOT CLEAR WHETHER THIS IS THE REMAINS OF IDA OR A SECOND LOW THAT
ABSORBS IDA.  AT THIS TIME...THE FORECAST USES THE SCENARIO THAT
THIS IS A SECOND LOW THAT ABSORBS THE REMAINS OF IDA.
 
WHILE IT IS LIKELY THAT IDA WILL LOSE TROPICAL CYCLONE
CHARACTERISTICS BEFORE REACHING THE NORTHERN GULF COAST...IT IS
POSSIBLE THAT TROPICAL STORM- OR HURRICANE-FORCE WINDS COULD REACH
PORTIONS OF THE COAST BEFORE EXTRATROPICAL TRANSITION IS COMPLETE. 
THUS...A HURRICANE WATCH HAS BEEN ISSUED FOR PORTIONS OF THE
NORTHERN GULF COAST AT THIS TIME.  OTHER POTENTIAL HAZARDS
ASSOCIATED WITH IDA ARE...FOR NOW...BEING HANDLED BY LOCAL NATIONAL
WEATHER SERVICE OFFICES ALONG THE GULF COAST IN THEIR PRODUCT SUITE
WITH MARINE AND COASTAL FLOOD WATCHES...WARNINGS...AND ADVISORIES.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      08/1500Z 21.2N  86.0W    80 KT
 12HR VT     09/0000Z 22.8N  87.1W    85 KT
 24HR VT     09/1200Z 25.6N  88.4W    85 KT
 36HR VT     10/0000Z 28.2N  88.6W    75 KT
 48HR VT     10/1200Z 30.0N  87.8W    65 KT...EXTRATROPICAL
 72HR VT     11/1200Z 30.5N  84.5W    40 KT...EXTRATROPICAL INLAND
 96HR VT     12/1200Z 30.0N  81.0W    30 KT...EXTRATROPICAL 
120HR VT     13/1200Z...ABSORBED BY EXTRATROPICAL LOW
 
$$
FORECASTER BEVEN
 

WTNT41 KNHC 081758
TCDAT1
HURRICANE IDA SPECIAL DISCUSSION NUMBER  19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
1200 PM CST SUN NOV 08 2009

THIS SPECIAL ADVISORY IS BEING ISSUED TO EXTEND THE HURRICANE WATCH
EASTWARD ALONG THE NORTHERN GULF COAST TO MEXICO BEACH FLORIDA. 
THERE ARE NO CHANGES TO THE TRACK FORECAST FROM THE PREVIOUS
REGULAR ADVISORY.  THE INITIAL INTENSITY IS SET TO 85 KT BASED ON
FLIGHT-LEVEL AND SFMR WIND DATA FROM AN AIR FORCE RESERVE HURRICANE
HUNTER AIRCRAFT THAT JUST PENETRATED THE CENTER.

THIS ADVISORY REPLACES THE SCHEDULED INTERMEDIATE ADVISORY AT
1800 UTC.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      08/1800Z 21.7N  86.1W    85 KT
 12HR VT     09/0000Z 22.8N  87.1W    85 KT
 24HR VT     09/1200Z 25.6N  88.4W    85 KT
 36HR VT     10/0000Z 28.2N  88.6W    75 KT
 48HR VT     10/1200Z 30.0N  87.8W    65 KT...EXTRATROPICAL
 72HR VT     11/1200Z 30.5N  84.5W    40 KT...EXTRATROPICAL INLAND
 96HR VT     12/1200Z 30.0N  81.0W    30 KT...EXTRATROPICAL
120HR VT     13/1200Z...ABSORBED BY EXTRATROPICAL LOW
 
$$
FORECASTER BEVEN
 

WTNT41 KNHC 082048
TCDAT1
HURRICANE IDA DISCUSSION NUMBER  20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
300 PM CST SUN NOV 08 2009
 
REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE
THAT THE CENTRAL PRESSURE OF IDA HAS FALLEN TO 976 MB.  THE
AIRCRAFT REPORTED MAXIMUM 700 MB FLIGHT-LEVEL WINDS OF 94 KT...WITH
SFMR ESTIMATES OF 80-85 KT.  BASED ON THIS...THE INITIAL INTENSITY
IS 85 KT.  SATELLITE IMAGERY AND RADAR DATA FROM MEXICO AND CUBA
SUGGEST THAT THE EYEWALL HAS BECOME LESS ORGANIZED DURING THE PAST
FEW HOURS...WHICH MAY BE A SIGN THAT IDA IS BEING AFFECTED BY
ONGOING SOUTHWESTERLY VERTICAL WIND SHEAR.
 
THE INITIAL MOTION IS 330/9.  IDA REMAINS BETWEEN A MID/UPPER-LEVEL
TROUGH OVER THE WESTERN GULF MEXICO AND ADJACENT LAND AREAS AND AN
MID/UPPER-LEVEL RIDGE OVER THE EASTERN GULF OF MEXICO AND THE
NORTHERN CARIBBEAN SEA.  IN ADDITION...A STRONG LOW-LEVEL RIDGE
COVERS THE NORTHERN GULF OF MEXICO.  THE DYNAMICAL MODELS FORECAST
THE TROUGH AND RIDGE TO MOVE EASTWARD...ALLOWING IDA TO TURN TOWARD
THE NORTH DURING THE NEXT 36 HR OR SO.  ALTHOUGH THE TRACK GUIDANCE
AGREES WITH THIS SCENARIO...THERE IS CONSIDERABLE SPREAD IN BOTH
THE LOCATION AND TIMING OF THE MODELS FORECAST LANDFALLS ON THE
NORTHERN GULF COAST.  THE ECMWF AND CANADIAN MODELS ARE ON THE
WESTERN EDGE OF THE ENVELOPE WITH A SOUTHEASTERN LOUISIANA
LANDFALL.  THE HWRF IS ON THE EASTERN EDGE WITH A LANDFALL IN THE
WESTERN FLORIDA PANHANDLE.  THE UKMET IS NOTABLE SLOWER THAN THE
OTHER GUIDANCE...CALLING FOR A LANDFALL AFTER 48 HR.  THE NEW
FORECAST TRACK COMPROMISES BETWEEN THESE EXTREMES AND LIES NEAR THE
VARIOUS CONSENSUS MODELS.  AFTER LANDFALL...THE MODEL SPREAD GETS
VERY LARGE DUE TO MAJOR MODEL DIFFERENCES ON THE EVOLUTION OF THE
WESTERLIES OVER THE SOUTHEASTERN UNITED STATES.  THE NEW TRACK
CALLS FOR A SLOW EASTWARD MOTION...BUT THIS PART OF THE TRACK IS
LOW CONFIDENCE.
 
THE HURRICANE MAY BE ABLE TO STRENGTHEN A LITTLE MORE IN THE NEXT
6-12 HR.  AFTER THAT...IDA WILL BE MOVING OVER COOLER SEA SURFACE
TEMPERATURES...INTO A COOLER AIR MASS...AND INTO STRONGER SHEAR.
WHILE EXTRATROPICAL TRANSITION SHOULD BEGIN BEFORE IDA MAKES
LANDFALL...IT IS UNCERTAIN IF THE CYCLONE WILL COMPLETELY LOSE ITS
TROPICAL CHARACTERISTICS BEFORE LANDFALL.  IN ADDITION...MOST OF
THE INTENSITY GUIDANCE FORECAST IDA TO MAINTAIN HURRICANE STRENGTH
UNTIL LANDFALL ON THE NORTHERN GULF COAST.  BASED ON THIS...THE NEW
INTENSITY FORECAST MAINTAINS IDA AS A WEAKENING HURRICANE THROUGH
LANDFALL...THEN FORECASTS EXTRATROPICAL TO FINISH AFTER LANDFALL.
IN THE 72-120 HR TIME FRAME...THE GFS...ECMWF...AND CANADIAN MODELS
FORECAST A LARGE BAROCLINIC LOW OFF THE U. S. EAST COAST.  IT IS
NOT CLEAR WHETHER THIS IS THE REMAINS OF IDA OR A SECOND LOW THAT
ABSORBS IDA.  THE FORECAST CONTINUES TO USE THE SCENARIO THAT
THIS IS A SECOND LOW THAT ABSORBS THE REMAINS OF IDA.
 
THE UNCERTAINTY OVER THE TIMING OF EXTRATROPICAL TRANSITION REQUIRES
A HURRICANE WATCH FOR PORTIONS OF THE NORTHERN GULF COAST.
REGARDLESS OF WHETHER IDA LOSES ITS TROPICAL CHARACTERISTICS BEFORE
LANDFALL...THE CYCLONE IS EXPECTED TO BRING STRONG WINDS...HEAVY
RAINS...AND STORM SURGES TO THAT AREA.  OUTSIDE OF THE HURRICANE
WATCH AREA....POTENTIAL HAZARDS ASSOCIATED WITH IDA ARE BEING
HANDLED BY LOCAL NATIONAL WEATHER SERVICE OFFICES ALONG THE GULF
COAST IN THEIR PRODUCT SUITE WITH MARINE AND COASTAL FLOOD
WATCHES...WARNINGS...AND ADVISORIES.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      08/2100Z 22.2N  86.3W    85 KT
 12HR VT     09/0600Z 23.9N  87.4W    85 KT
 24HR VT     09/1800Z 26.7N  88.0W    85 KT
 36HR VT     10/0600Z 29.2N  87.9W    75 KT
 48HR VT     10/1800Z 30.7N  86.7W    55 KT...EXTRATROPICAL INLAND
 72HR VT     11/1800Z 31.0N  83.0W    40 KT...EXTRATROPICAL INLAND
 96HR VT     12/1800Z 30.0N  79.5W    40 KT...EXTRATROPICAL
120HR VT     13/1800Z...ABSORBED BY EXTRATROPICAL LOW
 
$$
FORECASTER BEVEN
 

WTNT41 KNHC 090301
TCDAT1
HURRICANE IDA DISCUSSION NUMBER  21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
900 PM CST SUN NOV 08 2009
 
THE SATELLITE APPEARANCE OF IDA HAS CHANGED VERY LITTLE SINCE THE
AIRCRAFT DEPARTED THE HURRICANE JUST BEFORE 0000 UTC.  DURING THE
LAST COUPLE OF PASSES THROUGH THE CENTER THE AIRCRAFT MEASURED A
MAXIMUM 700 MB FLIGHT-LEVEL WIND OF 108 KT AND A SFMR SURFACE WIND
OF 84 KT. THESE DATA SUPPORT AN INTENSITY OF 90 KT.  ANOTHER AIR
FORCE PLANE IS SCHEDULED TO REACH IDA AROUND 0600 UTC. 

THE LAST FEW AIRCRAFT FIXES PROVIDE A FAIRLY CONFIDENT INITIAL
MOTION OF 345/12...A LITTLE FASTER THAN BEFORE.  IDA IS FORECAST TO
CONTINUE MOVING NORTHWARD BETWEEN A MID/UPPER-LEVEL TROUGH OVER THE
WESTERN GULF MEXICO AND A MID/UPPER-LEVEL RIDGE OVER THE EASTERN
GULF OF MEXICO AND THE NORTHERN CARIBBEAN SEA.  THE TRACK MODELS
APPEAR TO BE IN A LITTLE BETTER AGREEMENT ON A NORTH-NORTHWESTWARD
TO NORTHWARD TRACK DURING THE NEXT 24-36 HOURS.  THE 12Z RUNS OF
THE ECMWF AND UKMET ARE A LITTLE WEST OF THE REMAINDER OF THE
GUIDANCE AND SHOW A TRACK NEAR EXTREME SOUTHEASTERN LOUISIANA.
DURING THE FIRST 24-36 HOURS...THE NEW OFFICIAL FORECAST IS NEAR
THE MODEL CONSENSUS AND THE PREVIOUS TRACK...BUT IS A LITTLE
FASTER.  AFTER LANDFALL ALONG THE NORTHERN GULF COAST...THE MODELS
TURN IDA EASTWARD THEN SOUTHEASTWARD AND THE NHC FORECAST FOLLOWS
SUIT...BUT DOES NOT SHOW AS SHARP A SOUTHEASTWARD TURN AS SOME OF
THE GUIDANCE INDICATES.  THE AIR FORCE ALSO FLEW A SURVEILLANCE
MISSION AROUND AND NORTH OF THE HURRICANE THIS AFTERNOON AND THAT
DATA SHOULD BE ASSIMILATED INTO THE 0000 UTC MODELS.

IDA IS FORECAST TO TRAVERSE COOLER WATERS...AND MOVE INTO A
COOLER AIRMASS AND INCREASING SHEAR DURING THE NEXT 24-36 HOURS. 
AS THE CYCLONE APPROACHES THE NORTHERN GULF COAST IT WILL ALSO
LIKELY BEGIN EXTRATROPICAL TRANSITION.  HOWEVER...IT IS BECOMING
MORE LIKELY THAT IDA WILL RETAIN ITS TROPICAL CHARACTERISTICS
THROUGH LANDFALL.  THE INTENSITY GUIDANCE FORECASTS GRADUAL
WEAKENING AND ALL SHOW IDA AROUND HURRICANE STRENGTH AT LANDFALL. 
THE OFFICIAL FORECAST IS IN LINE WITH THE GUIDANCE AND KEEPS THE
CYCLONE A HURRICANE WHEN IT REACHES THE COAST.  THIS HAS REQUIRED
THE ISSUANCE OF A HURRICANE WARNING FOR A PORTION OF THE NORTHERN
GULF COAST. 
   
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      09/0300Z 23.7N  86.7W    90 KT
 12HR VT     09/1200Z 25.8N  87.5W    85 KT
 24HR VT     10/0000Z 28.5N  87.7W    75 KT
 36HR VT     10/1200Z 30.5N  87.1W    65 KT...INLAND
 48HR VT     11/0000Z 31.2N  85.8W    40 KT...EXTRATROPICAL
 72HR VT     12/0000Z 30.5N  82.0W    30 KT...EXTRATROPICAL
 96HR VT     13/0000Z...DISSIPATED
 
$$
FORECASTER BROWN
 

WTNT41 KNHC 090841
TCDAT1
HURRICANE IDA DISCUSSION NUMBER  22
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
300 AM CST MON NOV 09 2009
 
DATA FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT SHOW THAT
VERTICAL SHEAR IS BEGINNING TO TAKE A TOLL ON IDA.  THE MINIMUM
PRESSURE IS ESTIMATED TO HAVE RISEN TO 988 MB BASED ON A DROPSONDE
MEASUREMENT OF 991 WITH ABOUT 30 KT OF WIND.  ALSO...THE FLIGHT-
LEVEL AND SFMR WIND DATA SUGGEST THAT THE LOW-LEVEL CENTER IS
BECOMING INCREASINGLY DISPLACED TO THE SOUTH OF THE FLIGHT-LEVEL
CENTER.  THIS IS CONSISTENT WITH TRENDS SEEN IN RECENT
GEOSTATIONARY AND MICROWAVE SATELLITE IMAGERY...AS THE COLDEST CLOUD
TOPS HAVE BEEN DISPLACED TO THE NORTH OF THE AIRCRAFT FIXES. THE
MAXIMUM 700-MB FLIGHT LEVEL WIND MEASURED BY THE AIRCRAFT SO FAR
WAS 74 KT.  BASED ON THESE DATA...THE INITIAL INTENSITY IS LOWERED
TO 80 KT FOR THIS ADVISORY...AND THIS COULD BE A LITTLE GENEROUS.
 
THE SHEAR OVER IDA IS CURRENTLY ANALYZED AT MORE THAN 30 KT BY
UW-CIMSS...AND IS FORECAST TO INCREASE MARKEDLY OVER THE NEXT 24
HOURS. THIS...IN COMBINATION WITH COOLER WATERS ALONG THE TRACK OF
IDA OVER THE NORTHERN GULF SHOULD RESULT IN A CONTINUED WEAKENING
TREND. THE OFFICIAL INTENSITY FORECAST HAS BEEN ADJUSTED DOWNWARD
...AND IS CLOSE TO OR A LITTLE ABOVE THE ICON CONSENSUS THROUGH 36
HOURS. AT 48 HOURS...THE OFFICIAL FORECAST LEANS TOWARD THE DECAY
SHIPS AND LGEM SINCE THE SYSTEM WILL BE WELL INLAND BY THAT TIME.
AS IDA MOVES INTO COOLER WATERS AND A MORE BAROCLINIC ENVIRONMENT
...EXTRATROPICAL TRANSITION WILL LIKELY BEGIN IN THE NEXT 24 HOURS.  
MOST OF THE GUIDANCE SUGGESTS IDA WILL BE EXTRATROPICAL IN 48 HOURS
AND THIS IS REFLECTED IN THE OFFICIAL FORECAST.
 
THE LATEST FIXES FROM THE AIRCRAFT SUGGEST THAT IDA IS MOVING ALONG
A HEADING OF 335/14...FASTER AND A LITTLE TO THE LEFT OF THE
PREVIOUS TRACK. IDA IS EXPECTED TO ACCELERATE NORTHWARD TODAY AHEAD
OF A MID- TO UPPER-LEVEL TROUGH MOVING EASTWARD ACROSS THE
SOUTH-CENTRAL UNITED STATES AND NORTHERN GULF OF MEXICO. THE TRACK
MODEL GUIDANCE CONTINUES TO BE IN GENERALLY GOOD AGREEMENT ON THIS
SCENARIO...HOWEVER...THE UKMET AND ECMWF REMAIN WESTERN OUTLIERS
WITH A TRACK CLOSER TO THE COAST OF SOUTHEASTERN LOUISIANA. THE
OFFICIAL FORECAST HAS BEEN ADJUSTED WESTWARD FROM THE PREVIOUS
PACKAGE THROUGH 24 HOURS TOWARD THE MULTI-MODEL CONSENSUS. AFTER
LANDFALL...IDA IS EXPECTED TO SLOW AND TURN SHARPLY TOWARD THE
EAST...AND THE NHC FORECAST CONTINUES TO FOLLOW THIS SCENARIO. MOST
OF THE GLOBAL MODEL GUIDANCE...ALONG WITH THE GFDL...SHOW WHAT IS
LEFT OF IDA DISSIPATING BY 72 HOURS AS IT IS ABSORBED INTO A FRONT
THAT IS MOVING THROUGH THE SOUTHEASTERN U.S. BEHIND A DEVELOPING
BAROCLINIC LOW OFF OF THE CAROLINAS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      09/0900Z 25.1N  87.9W    80 KT
 12HR VT     09/1800Z 27.2N  88.2W    75 KT
 24HR VT     10/0600Z 29.6N  87.8W    70 KT
 36HR VT     10/1800Z 30.9N  86.7W    45 KT...INLAND
 48HR VT     11/0600Z 31.0N  85.0W    35 KT...EXTRATROPICAL INLAND
 72HR VT     12/0600Z...ABSORBED BY FRONT
 
$$
FORECASTER BRENNAN
 

WTNT41 KNHC 091454
TCDAT1
TROPICAL STORM IDA DISCUSSION NUMBER  23
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
900 AM CST MON NOV 09 2009
 
THE LAST RECONNAISSANCE DATA THAT SUPPORTED HURRICANE INTENSITY WERE
OBTAINED AROUND 07Z...AND THE SATELLITE PRESENTATION OF IDA HAS
BEEN STEADILY DETERIORATING DURING THE MORNING.  MOST OF THE DEEP
CONVECTION HAS BEEN SHEARED OFF WELL TO THE NORTHEAST OF THE CENTER
AND WILL BE MOVING ONSHORE SHORTLY...LEAVING ONLY A SMALL AREA OF
CONVECTION NEAR THE CENTER.  A QUIKSCAT PASS AROUND 12Z SHOWED
WINDS OF 50-55 KT IN THE CORE...AND ASSUMING THAT THE INSTRUMENT
DID NOT QUITE RESOLVE THE MAXIMUM WIND SPEED...THE ADVISORY
INTENSITY WILL BE SET TO 60 KT.  ANOTHER AIRCRAFT WILL BE IN THE
CYCLONE AROUND 18Z.

WITH IDA MOVING THROUGH AN ENVIRONMENT OF COOLER WATERS AND
INCREASING SHEAR...CONTINUED WEAKENING IS EXPECTED.  THE GLOBAL
MODELS DO NOT SHOW MUCH IN THE WAY OF BAROCLINIC RE-INTENSIFICATION
PRIOR TO LANDFALL...SO THE HURRICANE WARNINGS AND WATCHES ARE BEING
DISCONTINUED...LEAVING ONLY TROPICAL STORM WARNINGS IN PLACE.  THE
OFFICIAL FORECAST IS STILL ABOVE THE ICON CONSENSUS.   

THE LAST AIRCRAFT CENTER FIX SHOWED THE 700 MB- AND SURFACE CENTERS
DECOUPLING...AND SINCE THEN THE SURFACE CENTER HAS BEEN DIFFICULT
TO LOCATE IN SATELLITE IMAGERY. THE INITIAL MOTION IS ESTIMATED AT
340/15. THE FORECAST PHILOSOPHY IS UNCHANGED. IDA IS EXPECTED TO
MOVE GENERALLY NORTHWARD TODAY AHEAD OF A MID- TO UPPER-LEVEL
TROUGH MOVING EASTWARD ACROSS THE NORTHERN GULF OF MEXICO...AND
THEN TURN EASTWARD AS IT BECOMES EMBEDDED WITHIN THIS MID-LATITUDE
SYSTEM.

THE TRACK OF THE SURFACE CENTER OF IDA IS LOSING SIGNIFICANCE IN
TERMS OF THE EFFECTS OF THIS STORM.  STRONG WINDS COVER A LARGE
AREA OF THE GULF OF MEXICO AND THE ASSOCIATED RAINS ARE MOVING WELL
AHEAD OF THE CENTER.  THIS SHOULD CONTINUE TO BE THE CASE AS IDA
WEAKENS AND BEGINS TO LOSE TROPICAL CHARACTERISTICS. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      09/1500Z 26.5N  88.3W    60 KT
 12HR VT     10/0000Z 28.6N  88.7W    55 KT
 24HR VT     10/1200Z 30.4N  88.2W    50 KT...INLAND
 36HR VT     11/0000Z 31.2N  86.6W    40 KT...EXTRATROPICAL
 48HR VT     11/1200Z 30.5N  84.5W    30 KT...EXTRATROPICAL
 72HR VT     12/1200Z...DISSIPATED
 
$$
FORECASTER FRANKLIN
 

WTNT41 KNHC 092056
TCDAT1
TROPICAL STORM IDA DISCUSSION NUMBER  24
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
300 PM CST MON NOV 09 2009
 
WITH ONE INTERESTING EXCEPTION...THE LATEST REPORTS FROM AN AIR
FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT INDICATE THAT IDA
REMAINS JUST BELOW HURRICANE STRENGTH. A CONVECTIVE BURST THAT
BEGAN A FEW HOURS AGO HAS TEMPORARILY HALTED THE WEAKENING TREND.
PEAK 850 MB FLIGHT-LEVEL WINDS OF 75 KT AND PEAK SFMR WINDS OF 58
KT SUPPORT MAINTAINING THE ADVISORY INTENSITY AT 60 KT. ON THE MOST
RECENT OUTBOUND PASS...HOWEVER...THE SFMR DID REPORT A VERY SMALL
AREA OF 70-75 KT SURFACE WINDS SOUTHWEST OF THE CENTER JUST
DOWNWIND OF THE CONVECTIVE BURST. GIVEN THAT THE CONCURRENT
FLIGHT-LEVEL WINDS WERE ONLY 45 TO 55 KT...THIS APPEARS TO BE A
LOCAL CONVECTIVE-SCALE PEAK UNREPRESENTATIVE OF THE CIRCULATION.

SSTS BELOW THE CENTER ARE NOW ABOUT 26C...AND GET PROGRESSIVELY
COOLER ALONG THE PROJECTED TRACK. VERTICAL WIND SHEAR WILL ALSO BE
INCREASING OVER THE NEXT 12 HOURS OR SO. THE 12Z GLOBAL MODELS
STILL DO NOT SHOW MUCH IN THE WAY OF BAROCLINIC RE-INTENSIFICATION
PRIOR TO LANDFALL...AND SO A RESUMPTION OF THE EARLIER WEAKENING
TREND IS EXPECTED TO COMMENCE SOON.

IDA IS NOW MOVING NORTHWARD...355/16. THE DYNAMICAL GUIDANCE
INDICATES THAT THE FORWARD MOTION SHOULD SLOW APPRECIABLY OVER THE
NEXT 12 HOURS...BUT IF THE CONVECTION PERSISTS MUCH LONGER IDA WILL
LIKELY MOVE ON SHORE SOONER THAN FORECAST. MY OFFICIAL 12 HOUR
FORECAST POINT IS ALREADY AHEAD OF MOST OF THE GUIDANCE. THE
REMAINDER OF THE FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY
TRACK...AND CALLS FOR IDA TO TURN EASTWARD AFTER LANDFALL AS IT
BECOMES EMBEDDED WITHIN A MID-LATITUDE TROUGH MOVING EASTWARD FROM
THE WESTERN GULF.
 
STRONG WINDS COVER A LARGE AREA OF THE GULF OF MEXICO AND RAINBANDS
ARE ALREADY MOVING ONSHORE WELL AHEAD OF THE CENTER.  GIVEN THE
CURRENT MOTION AND CONVECTIVE VIGOR...IDA SHOULD MAINTAIN TROPICAL
CHARACTERISTICS THROUGH LANDFALL. 
 

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      09/2100Z 28.4N  88.5W    60 KT
 12HR VT     10/0600Z 30.2N  88.1W    50 KT
 24HR VT     10/1800Z 31.0N  87.1W    40 KT...INLAND
 36HR VT     11/0600Z 31.0N  85.5W    30 KT...EXTRATROPICAL
 48HR VT     11/1800Z 30.0N  83.5W    25 KT...EXTRATROPICAL
 72HR VT     12/1800Z...DISSIPATED
 
$$
FORECASTER FRANKLIN
 

WTNT41 KNHC 100300
TCDAT1
TROPICAL STORM IDA DISCUSSION NUMBER  25
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
900 PM CST MON NOV 09 2009
 
RADAR AND SATELLITE IMAGES SHOW THE CONVECTION THAT WAS NEAR THE
CENTER DURING THE AFTERNOON HAS WEAKENED AND SHEARED OFF TOWARD THE
NORTH.  THIS WAS CONFIRMED BY A RECENT AIRCRAFT FIX THAT POSITIONED
THE CENTER EAST OF SOUTHEASTERN LOUISIANA WELL SOUTH OF THE
REMAINING DEEP CONVECTION.  THE FORWARD SPEED OF IDA HAS SLOWED TO
ABOUT 11 KT.  THE DYNAMICAL MODEL GUIDANCE FORECASTS A CONTINUED
REDUCTION IN THE FORWARD MOTION OF THE STORM AND A TURN TOWARD THE
EAST AFTER LANDFALL.  THE NHC FORECAST IS CLOSE TO THE PREVIOUS
ADVISORY THROUGH 12 HOURS AND IS THEN ADJUSTED A LITTLE NORTHWARD
CLOSER TO THE MODEL CONSENSUS.

THE AIRCRAFT HAS RECENTLY MEASURED A PEAK 850 MB FLIGHT-LEVEL WIND
OF 71 KT AND A SMFR SURFACE WIND OF 51 KT.  THIS SUPPORTS AN
INITIAL INTENSITY OF 55 KT.  IDA SHOULD GRADUALLY WEAKEN THROUGH
LANDFALL DUE TO INCREASING SHEAR AND COOLER SSTS.  ONCE INLAND THE
CYCLONE WILL WEAKEN AT A FASTER RATE AND BECOME EXTRATROPICAL
SHORTLY THEREAFTER.  MOST OF THE GLOBAL MODELS SHOW THE CYCLONE
BEING ABSORBED BY A FRONTAL BOUNDARY IN 36-48 HOURS AND SO DOES THE
OFFICIAL FORECAST. 
   
THE LOCATION AND TIMING OF IDA'S LANDFALL WILL HAVE LITTLE
SIGNIFICANCE SINCE THE TROPICAL STORM FORCE WINDS COVER A LARGE
AREA AND MOST OF THE HEAVIER RAINFALL IS ALREADY SPREADING ONSHORE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      10/0300Z 29.3N  88.6W    55 KT
 12HR VT     10/1200Z 30.8N  87.9W    40 KT...EXTRATROPICAL
 24HR VT     11/0000Z 31.5N  86.5W    30 KT...EXTRATROPICAL
 36HR VT     11/1200Z 31.3N  84.8W    25 KT...EXTRATROPICAL
 48HR VT     12/0000Z...DISSIPATED
 
$$
FORECASTER BROWN/BERG
 

WTNT41 KNHC 100842
TCDAT1
TROPICAL STORM IDA DISCUSSION NUMBER  26
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
300 AM CST TUE NOV 10 2009
 
THE CENTER OF IDA IS NOW DEVOID OF DEEP CONVECTION...AS THE COLDEST
CLOUD TOPS HAVE CONTINUED TO SHEAR OFF TOWARD THE NORTH AND EAST
OVER THE PAST SEVERAL HOURS. DATA FROM AIRCRAFT RECONNAISSANCE SHOW
THAT THE CENTRAL PRESSURE HAS SLOWLY RISEN TO 999 MB.  THE HIGHEST
850-MB FLIGHT LEVEL WIND REPORTED BY THE HURRICANE HUNTER AIRCRAFT
WAS 53 KT AT 0733 UTC...AND THE HIGHEST RELIABLE SFMR WINDS WERE
AROUND 40 KT.  WINDS AT THE NUMEROUS MARINE PLATFORMS ALONG THE
GULF COAST HAVE ALSO BEEN SLOWLY DECREASING OVER THE PAST FEW HOURS.
BASED ON ALL THIS...THE INITIAL INTENSITY IS LOWERED TO 45 KT FOR
THIS ADVISORY. A GRADUAL SPIN DOWN OF THE SYSTEM IS FORECAST...
ALTHOUGH IDA IS STILL EXPECTED TO BE AT TROPICAL STORM INTENSITY
WHEN IT COMPLETES EXTRATROPICAL TRANSITION LATER TODAY. MOST OF THE
GUIDANCE SHOWS THE LOW-LEVEL CIRCULATION OF IDA BEING ABSORBED INTO
A FRONTAL ZONE ASSOCIATED WITH A BAROCLINIC LOW THAT DEVELOPS OFF
THE SOUTHEAST U.S. COAST IN ABOUT 48 HOURS.
 
AIRCRAFT FIXES AND SATELLITE IMAGERY OVERNIGHT INDICATED THAT IDA
WAS MOVING ONLY VERY SLOWLY NORTHWARD FOR SEVERAL HOURS. HOWEVER
THE LAST COUPLE OF AIRCRAFT FIXES AND MULTI-CHANNEL SATELLITE
IMAGERY SUGGEST THAT A FASTER MOTION JUST EAST OF DUE NORTH MAY
HAVE BEGUN...AND THE INITIAL MOTION ESTIMATE IS 005/08. DATA FROM
THE AIRCRAFT AND SATELLITE IMAGERY ALSO SUGGEST THAT THE LOW-LEVEL
CENTER IS BECOMING ELONGATED AND LESS WELL-DEFINED. THE DYNAMICAL
GUIDANCE IS INSISTENT ON A TURN TOWARD THE NORTHEAST WHICH COULD BE
BEGINNING NOW AND FINALLY WOULD BRING THE CENTER INLAND LATER
TODAY. THE OFFICIAL FORECAST IS SLOWER AND FARTHER SOUTH THAN THE
PREVIOUS PACKAGE DUE TO THE SLOWER INITIAL MOTION AND MORE WESTERLY
INITIAL POSITION AND A SOUTHWARD TREND IN THE MODEL GUIDANCE. 
 
THE FACT THAT THE LANDFALL OF IDA HAS BEEN DELAYED HAS LITTLE
SIGNIFICANCE SINCE THE TROPICAL STORM FORCE WINDS COVER A LARGE
AREA AWAY FROM THE CENTER AND MOST OF THE HEAVY RAINFALL HAS
ALREADY SPREAD ONSHORE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      10/0900Z 29.9N  88.5W    45 KT
 12HR VT     10/1800Z 30.8N  88.0W    35 KT...EXTRATROPICAL
 24HR VT     11/0600Z 31.0N  86.4W    30 KT...EXTRATROPICAL
 36HR VT     11/1800Z 30.4N  84.4W    25 KT...EXTRATROPICAL
 48HR VT     12/0600Z...DISSIPATED
 
$$
FORECASTER BRENNAN
 

WTNT41 KNHC 101435
TCDAT1
TROPICAL DEPRESSION IDA DISCUSSION NUMBER  27
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
900 AM CST TUE NOV 10 2009
 
SATELLITE AND SURFACE OBSERVATIONS INDICATE THAT IDA HAS BECOME
EXTRATROPICAL.  THE LATEST SATELLITE IMAGERY SHOWS A COMMA-LIKE
APPEARANCE AND TEMPERATURE DATA FROM DAUPHIN ISLAND SHOWED A 5F
TEMPERATURE DECREASE AFTER THE CENTER PASSED THIS MORNING.  ALTHOUGH
THERE HAVE BEEN A COUPLE OF ELEVATED MARINE STATIONS REPORTING
SUSTAINED WINDS OVER 34 KT...THERE ARE NO INDICATIONS THAT THESE
WINDS ARE SURFACE-BASED...SO THE INITIAL INTENSITY IS SET TO 30 KT. 
ALTHOUGH THE NHC INTENSITY FORECAST SHOWS LITTLE CHANGE WITH IDA
DURING THE NEXT DAY OR SO...THESE WINDS SHOULD BE MOSTLY CONFINED
OVER WATER.  

THE INITIAL MOTION IS 045/8.  GUIDANCE IS IN FAIR AGREEMENT ON IDA
TURNING EASTWARD AS IT BECOMES ENTRAINED INTO A DEVELOPING FRONTAL
SYSTEM AND THE NHC FORECAST IS BASICALLY AN UPDATE OF THE PREVIOUS
FORECAST.  ALTHOUGH THE NEW FORECAST WILL SHOW ABSORPTION OF IDA BY
A NEW MID-LATITUDE LOW...IT IS POSSIBLE THAT IDA WILL BECOME THE
DOMINANT BAROCLINIC LOW.  

THIS IS THE LAST ADVISORY ON THIS SYSTEM ISSUED BY THE NATIONAL
HURRICANE CENTER. FUTURE INFORMATION ON THIS SYSTEM CAN BE FOUND IN
PUBLIC ADVISORIES ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION 
CENTER...UNDER AWIPS HEADER TCPAT1 AND WMO HEADER WTNT31
KWNH...BEGINNING AT 3 PM CST.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      10/1500Z 30.6N  87.6W    30 KT...EXTRATROPICAL
 12HR VT     11/0000Z 30.9N  86.5W    30 KT...EXTRATROPICAL
 24HR VT     11/1200Z 30.7N  84.9W    30 KT...EXTRATROPICAL
 36HR VT     12/0000Z 30.0N  82.5W    25 KT...EXTRATROPICAL
 48HR VT     12/1200Z...ABSORBED 
 
$$
FORECASTER BLAKE/CANGIALOSI
 

