WTNT42 KNHC 250843
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
500 AM EDT TUE SEP 25 2007
 
SATELLITE IMAGERY INDICATES THAT TROPICAL DEPRESSION TWELVE HAS
CONTINUED TO GRADUALLY ORGANIZE...WITH INCREASED CONVECTIVE BANDING
OVER A LARGE AREA SURROUNDING THE CENTER.  SATELLITE INTENSITY
ESTIMATES FROM TAFB AND SAB ARE AGAIN 35 KT...SO THE DEPRESSION IS
UPGRADED TO TROPICAL STORM KAREN.

THE INITIAL MOTION REMAINS 285/14.  KAREN IS ON THE SOUTH SIDE OF A
LOW/MID-LEVEL RIDGE...WHICH SHOULD STEER THE CYCLONE FOR THE NEXT
36-48 HR.  AFTER THAT...THE LARGE-SCALE MODELS AGREE ON THE
DEVELOPMENT OF A MID/UPPER-LEVEL TROUGH TO THE NORTHEAST OF THE
LESSER ANTILLES...WHICH WOULD TURN KAREN NORTHWESTWARD OR
NORTHWARD.  THERE IS SOME SPREAD IN THE GUIDANCE...WITH THE
GFDL...HWRF...ANND ECMWF SHOWING A NORTHWARD MOTION BETWEEN
50W-53W...WHILE THE UKMET AND GFS ENSEMBLE MEAN SHOW A
NORTHWESTWARD MOTION TO WEST OF 56W BY 120 HR.  SINCE THERE IS
OFTEN A TENDENCY FOR THE DYNAMICAL MODELS TO HAVE A NORTHWARD BIAS
IN THE TROPICAL ATLANTIC...THE NEW FORECAST TRACK IS ALONG THE
SOUTH EDGE OF THE MODEL GUIDANCE FOR THE FIRST 72 HR...AND THEN TO
THE LEFT OF CENTER OF THE GUIDANCE ENVELOPE THEREAFTER.

THE INTENSITY FORECAST...IF ANYTHING...HAS BECOME MORE PROBLEMATIC. 
KAREN IS CURRENTLY IN AN ENVIRONMENT OF LIGHT NORTHWESTERLY VERTICAL
WIND SHEAR...WHICH SHOULD CONTINUE FOR 24-36 HR.  AFTER THAT...AN
UPPER-LEVEL TROUGH IS FORECAST TO DEVELOP VERY CLOSE TO THE STORM
TRACK...FOLLOWED BY THE DEVELOPMENT OF THE MID/UPPER-LEVEL TROUGH
MENTIONED ABOVE.  THE LARGE-SCALE MODELS FORECAST THE FIRST TROUGH
TO CAUSE BOTH STRONG UPPER-LEVEL DIFLUENCE AND SHEAR OVER KAREN...
AND IT IS UNCLEAR AT THIS TIME WHETHER THIS SYSTEM WOULD CAUSE THE
STORM TO INTENSIFY OR WEAKEN.  THE SECOND TROUGH IS FORECAST TO
CAUSE SIGNIFICANT SHEAR WITHOUT STRONG DIFLUENCE...WHICH SHOULD
CAUSE WEAKENING.  THE SHIPS...GFDL...AND HWRF MODELS ALL FORECAST
KAREN TO BECOME A HURRICANE BY 60-72 HR.  GIVEN THE UNCERTAINTY IN
THE STRENGTH OF THE SHEAR...THE INTENSITY FORECAST CALLS FOR KAREN
TO PEAK JUST BELOW HURRICANE STRENGTH...FOLLOWED BY WEAKENING DUE
TO SHEAR FROM THE SECOND TROUGH.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      25/0900Z 10.4N  38.0W    35 KT
 12HR VT     25/1800Z 10.8N  40.0W    40 KT
 24HR VT     26/0600Z 11.3N  43.0W    45 KT
 36HR VT     26/1800Z 11.8N  45.7W    55 KT
 48HR VT     27/0600Z 12.9N  47.9W    60 KT
 72HR VT     28/0600Z 16.0N  51.0W    60 KT
 96HR VT     29/0600Z 19.0N  53.0W    55 KT
120HR VT     30/0600Z 22.0N  54.5W    55 KT
 
$$
FORECASTER BEVEN
 

WTNT42 KNHC 251433
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
1100 AM EDT TUE SEP 25 2007

KAREN IS EXHIBITING SOME BANDING FEATURES ON VISIBLE SATELLITE
IMAGERY BUT THE DEEP CONVECTION IS NOT THAT STRONG OR CONCENTRATED
NEAR THE CENTER AT THIS TIME.  DVORAK INTENSITY ESTIMATES FROM TAFB
AND SAB REMAIN AT 35 KT SO THE CURRENT INTENSITY IS UNCHANGED FROM
THE PREVIOUS ADVISORY.  THE ENVIRONMENT AHEAD OF THE STORM IS
QUESTIONABLE FOR STRENGTHENING.  KAREN'S UPPER-LEVEL OUTFLOW IS
BEING RESTRICTED OVER THE NORTHWEST QUADRANT DUE TO A NEARBY
UPPER-LEVEL CYCLONIC SHEAR AXIS.  WITHIN THE NEXT FEW DAYS...
GLOBAL MODELS DEPICT A COUPLE OF UPPER-LEVEL TROUGHS OVER THE
CENTRAL SUBTROPICAL ATLANTIC THAT SHOULD CAUSE INCREASING
SOUTHWESTERLY VERTICAL SHEAR OVER THE TROPICAL CYCLONE.  THE SHIPS
MODEL...USING THE GFS FORECAST...SHOWS THE SHEAR INCREASING TO 20 KT
BY 60 HOURS AND MORE THAN 30 KT NEAR THE END OF THE PERIOD.  IN
SPITE OF THIS SEEMINGLY HOSTILE ENVIRONMENT...SHIPS PREDICTS KAREN
TO BECOME A HURRICANE BY 48 HOURS AND TO MAINTAIN HURRICANE
STRENGTH ALMOST TO THE END OF THE FORECAST PERIOD.  THE LATEST RUN
OF THE GFDL MODEL ALSO INTENSIFIES THE TROPICAL STORM INTO A
HURRICANE AFTER 72 HOURS.  IT IS DIFFICULT TO ACCEPT THIS GUIDANCE
IN THE FACE OF SUCH STRONG PREDICTED SHEAR.  THEREFORE THE OFFICIAL
FORECAST...AS IN THE PREVIOUS PACKAGE...STRENGTHENS KAREN TO JUST
BELOW HURRICANE STATUS AND THEN INDICATES WEAKENING AFTER DAY 3.

INITIAL MOTION...290/13 THE SAME AS IN THE PREVIOUS ADVISORY.  KAREN
CONTINUES ON THE SOUTH SIDE OF A LOW- TO MID-LEVEL SUBTROPICAL
RIDGE.  THIS SCENARIO SHOULD PERSIST FOR THE NEXT DAY OR SO. 
AFTERWARDS...A MID- TO UPPER-TROPOSPHERIC CYCLONE SHOULD CREATE A
WEAKNESS IN THE RIDGE.  IF THIS OCCURS...KAREN SHOULD GRADUALLY
TURN NORTHWESTWARD AND THEN NORTH-NORTHWESTWARD.  THERE CONTINUES
TO BE A FAIR AMOUNT OF SPREAD IN THE TRACK GUIDANCE MODELS.  THE
HWRF AND GFS TRACKS ARE NEAR THE RIGHT SIDE OF THE GUIDANCE
ENVELOPE AND THE U.K. MET MODEL TRACK IS NEAR THE LEFT SIDE.  THE
OFFICIAL FORECAST IS CLOSE TO THE DYNAMICAL CONSENSUS...NOT FAR
FROM THE GFDL TRACK...AND FAIRLY SIMILAR TO THE PREVIOUS NHC TRACK.

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      25/1500Z 10.8N  38.7W    35 KT
 12HR VT     26/0000Z 11.2N  40.7W    40 KT
 24HR VT     26/1200Z 11.8N  43.5W    45 KT
 36HR VT     27/0000Z 12.5N  46.1W    55 KT
 48HR VT     27/1200Z 13.9N  48.3W    60 KT
 72HR VT     28/1200Z 17.2N  51.2W    60 KT
 96HR VT     29/1200Z 20.0N  53.0W    55 KT
120HR VT     30/1200Z 22.5N  54.0W    55 KT
 
$$
FORECASTER PASCH
 

WTNT42 KNHC 252033
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER   4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
500 PM EDT TUE SEP 25 2007
 
KAREN CONTINUES TO SHOW SOME BANDING FEATURES AND A WELL-DEFINED
CIRCULATION ON VISIBLE IMAGES...BUT ITS PRESENTATION ON INFRARED
IMAGERY IS NOT VERY IMPRESSIVE.  THE SYSTEM CONTINUES TO LACK MUCH
IN THE WAY OF CENTRAL DEEP CONVECTION AND...IN FACT...THE OVERALL
AMOUNT OF DEEP CONVECTION IS MINIMAL.  DVORAK SATELLITE
CLASSIFICATIONS ARE HOLDING AT 35 KT FROM BOTH TAFB AND SAB...SO
THE ADVISORY INTENSITY IS UNCHANGED.  THE UPPER-LEVEL OUTFLOW OVER
THE NORTHERN SEMICIRCLE HAS BECOME A LITTLE BETTER ESTABLISHED
AND...IF KAREN DEVELOPS SOME MORE CENTRAL CONVECTION...IT COULD
STRENGTHEN SOME DURING THE NEXT COUPLE OF DAYS.  HOWEVER...AN
UPPER-TROPOSPHERIC TROUGH THAT THE GFS DEPICTS DEVELOPING IN THE
VICINITY OF 55 W IN 2-3 DAYS SHOULD EVENTUALLY PRODUCE STRONG
SOUTH-SOUTHWESTERLY SHEAR OVER KAREN.  THEREFORE THE OFFICIAL
INTENSITY FORECAST DOES NOT INDICATE THAT KAREN WILL BECOME A
HURRICANE...AND SHOWS WEAKENING BEYOND DAY 3.  THIS IS GENERALLY
BELOW THE GFDL AND HWRF GUIDANCE BUT IN REASONABLE AGREEMENT WITH
THE LATEST SHIPS OUTPUT.  THE LGEM VERSION OF SHIPS...WHICH IS MORE
RESPONSIVE TO CHANGES IN SHEAR OVER THE FORECAST PERIOD...SHOWS
LESS INTENSIFICATION.

INITIAL MOTION CONTINUES AT 285/13.  A DEEP-LAYERED SUBTROPICAL
RIDGE SITUATED TO THE NORTH OF THE CYCLONE SHOULD INDUCE A GENERAL
WEST-NORTHWESTWARD MOTION DURING THE NEXT 24 TO 36 HOURS.  BY MID-
PERIOD...AN AMPLIFYING MID- TO UPPER-LEVEL TROUGH IS EXPECTED TO
CREATE A PRONOUNCED WEAKNESS IN THE AFOREMENTIONED RIDGE.  THIS
FEATURE SHOULD CAUSE KAREN TO GRADUALLY TURN NORTHWESTWARD...AND BY
THE END OF THE FORECAST PERIOD...NORTH-NORTHWESTWARD.  THIS NHC
FORECAST TRACK IS ESSENTIALLY A BLEND OF THE GFDL...GFS...AND U.K.
MET OFFICE SOLUTIONS. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      25/2100Z 11.1N  39.9W    35 KT
 12HR VT     26/0600Z 11.5N  41.9W    40 KT
 24HR VT     26/1800Z 12.3N  44.6W    45 KT
 36HR VT     27/0600Z 13.3N  47.1W    55 KT
 48HR VT     27/1800Z 14.7N  48.8W    60 KT
 72HR VT     28/1800Z 17.5N  51.0W    60 KT
 96HR VT     29/1800Z 20.0N  52.5W    55 KT
120HR VT     30/1800Z 22.5N  53.5W    55 KT
 
$$
FORECASTER ROBERTS/PASCH
 

WTNT42 KNHC 260245
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
1100 PM EDT TUE SEP 25 2007

AFTER LOOKING RATHER UNIMPRESSIVE IN INFRARED SATELLITE IMAGERY
DURING THE AFTERNOON...DEEP CONVECTION HAS REDEVELOPED NEAR
THE CENTER OF KAREN AND BANDING FEATURES HAVE BECOME A LITTLE
BETTER DEFINED WITHIN THE PAST COUPLE OF HOURS.  HOWEVER...
SATELLITE INTENSITY ESTIMATES AND QUIKSCAT DATA SUGGEST THAT THE
MAXIMUM WINDS REMAIN 35 KT.  

THE INITIAL MOTION IS 285/12.  THE TRACK FORECAST SCENARIO REMAINS
THE SAME WITH KAREN MOVING WEST-NORTHWESTWARD SOUTH OF A DEEP-LAYER
RIDGE DURING THE NEXT COUPLE OF DAYS.  THEREAFTER...A WEAKNESS IN
THE RIDGE IS EXPECTED TO DEVELOP OVER THE CENTRAL ATLANTIC...
ALLOWING A TURN TOWARD THE NORTHWEST.  THE GFS AND UKMET
MODELS...WHICH HAVE PERFORMED WELL IN THE ATLANTIC SO FAR THIS
YEAR...ARE ALONG THE SOUTHERN EDGE OF THE GUIDANCE ENVELOPE AND THE
OFFICIAL FORECAST LEANS TOWARDS THESE SOLUTIONS.

THE LARGE AND BROAD CIRCULATION OF KAREN HAS LIKELY INHIBITED
STRENGTHENING DURING THE PAST 24 HOURS.  WITH THE RECENT
DEVELOPMENT OF CONVECTION NEAR THE CENTER AND THE FACT THAT
THE UPPER-LEVEL OUTFLOW HAS CONTINUED TO BECOME BETTER
ESTABLISHED...IT APPEARS THAT KAREN SHOULD STRENGTHEN DURING
THE NEXT DAY OR TWO.  THEREAFTER...IT REMAINS UNCLEAR AS TO EXACTLY
WHAT ROLE A DEVELOPING UPPER-LEVEL TROUGH NORTHEAST OF THE LEEWARD
ISLANDS WILL HAVE ON THE CYCLONE.  THE GFS DEVELOPS THIS TROUGH A
LITTLE FARTHER WEST THAN THE REMAINDER OF THE DYNAMICAL MODELS AND
KEEPS A MORE FAVORABLE OUTFLOW PATTERN OVER KAREN FOR A LITTLE
LONGER.  HOWEVER...BY DAYS 4-5...KAREN IS FORECAST TO MOVE CLOSE
ENOUGH TO THE UPPER-LEVEL TROUGH THAT SOUTHWESTERLY SHEAR WOULD
INCREASE.  DESPITE THIS SEEMINGLY UNFAVORABLE ENVIRONMENT LATE IN
THE FORECAST PERIOD...THE GFDL AND HWRF MODELS CONTINUE TO
STRENGTHEN KAREN TO A HURRICANE.  THE SHIPS AND LGEM MODELS SHOW
LITTLE CHANGE IN STRENGTH AFTER 48-72 HOURS.  THE OFFICIAL
INTENSITY FORECAST BLENDS THE STATISTICAL MODELS AND SHOWS A 
LITTLE LESS INTENSIFICATION THAN IN THE PREVIOUS ADVISORY.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      26/0300Z 11.1N  41.0W    35 KT
 12HR VT     26/1200Z 11.6N  43.0W    40 KT
 24HR VT     27/0000Z 12.6N  45.5W    45 KT
 36HR VT     27/1200Z 13.8N  47.6W    50 KT
 48HR VT     28/0000Z 15.3N  49.4W    55 KT
 72HR VT     29/0000Z 17.7N  51.4W    55 KT
 96HR VT     30/0000Z 20.0N  53.0W    50 KT
120HR VT     01/0000Z 22.5N  54.5W    50 KT
 
$$
FORECASTER BROWN
 

WTNT42 KNHC 260838
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER   6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
500 AM EDT WED SEP 26 2007
 
AFTER LOOKING RATHER ANEMIC YESTERDAY...KAREN IS FINALLY STARTING TO
PRODUCE PRODUCE DEEP CONVECTION NEAR THE CENTER AND MICROWAVE DATA
SUGGEST THE EARLY STAGES OF AN INNER CORE.  SATELLITE INTENSITY
ESTIMATES HAVE RISEN AND THE INITIAL INTENSITY IS INCREASED TO 45
KT.
 
KAREN IS MOVING RIGHT ALONG THE PREVIOUS FORECAST TRACK WITH AN
INITIAL MOTION OF 280/11.  THE CYCLONE IS EXPECTED TO GRADUALLY
TURN NORTHWESTWARD OVER THE NEXT COUPLE OF DAYS AS A SMALL WEAKNESS
DEVELOPS IN THE DEEP-LAYER SUBTROPICAL RIDGE OVER THE CENTRAL
ATLANTIC.  THEREAFTER...THE GLOBAL MODELS DIFFER IN THEIR FORECAST
OF A LARGE MIDDLE-UPPER LEVEL TROUGH EXPECTED TO DEVELOP OVER THE
WESTERN ATLANTIC.  THE NOGAPS...GFDN...AND HWRF MODEL SHOW THIS
TROUGH REMAINING IN PLACE LONG ENOUGH TO KEEP THE CYCLONE MOVING
NORTHWESTWARD THROUGHOUT THE ENTIRE FORECAST PERIOD.  CONVERSELY...
THE UKMET QUICKLY LIFTS THE SAME TROUGH NORTHWARD BEYOND 72 HOURS
ALLOWING THE CYCLONE TO TURN WESTWARD UNDER THE INFLUENCE OF A
DEVELOPING WEST ATLANTIC RIDGE.  THE GFS IS BETWEEN THESE TWO
SOLUTIONS AS IT SHOWS THE TROUGH SIMILARLY LIFTING NORTHWARD BUT
WITH A MUCH WEAKER RIDGE IN ITS WAKE.  THIS PATTERN WOULD KEEP THE
CYCLONE MOVING GENERALLY NORTHWESTWARD...ALBEIT VERY SLOWLY.  THE
OFFICIAL FORECAST LEANS TOWARD THE GFS SOLUTION BASED ITS PAST
PERFORMANCE AND IS A LITTLE TO THE LEFT OF THE DYNAMICAL MODEL
CONSENSUS.  THIS FORECAST IS ALSO CLOSE TO THE FSU SUPERENSEMBLE.
 
WITH THE RECENT DEVELOPMENT OF CONVECTION NEAR THE CENTER AND
GENERALLY FAVORABLE ENVIRONMENTAL CONDITIONS...KAREN SHOULD
STRENGTHEN DURING THE NEXT DAY OR TWO.  THEREAFTER...THE INTENSITY
FORECAST BECOMES HIGHLY PROBLEMATIC DUE TO THE POSSIBLE DEVELOPMENT
OF UNFAVORABLE UPPER-LEVEL WINDS.  THE GLOBAL MODELS SHOW STRONG
WESTERLY FLOW IMPINGING UPON THE CYCLONE IN A DAY OR TWO.
HOWEVER...NEITHER THE GFDL NOR THE HWRF MODELS RESPOND TO THE SHEAR
AND CONTINUE TO STRENGTHEN KAREN THROUGHOUT THE FORECAST.  IN
FACT...THE HWRF MODEL MAKES KAREN A CATEGORY 2 HURRICANE BY DAY 5.
SINCE SUCH ROBUST DEVELOPMENT SEEMS QUESTIONABLE GIVEN THE EXPECTED
INCREASE IN VERTICAL SHEAR...THE OFFICIAL FORECAST IS BASED MORE ON
THE SHIPS AND LGEM MODELS WHICH SHOW KAREN REACHING MINIMAL
HURRICANE STRENGTH IN A DAY OR TWO FOLLOWED BY SLIGHT WEAKENING.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      26/0900Z 11.2N  42.1W    45 KT
 12HR VT     26/1800Z 11.9N  43.9W    55 KT
 24HR VT     27/0600Z 13.0N  46.1W    60 KT
 36HR VT     27/1800Z 14.3N  48.0W    65 KT
 48HR VT     28/0600Z 15.6N  49.4W    65 KT
 72HR VT     29/0600Z 18.0N  51.5W    60 KT
 96HR VT     30/0600Z 20.0N  53.0W    55 KT
120HR VT     01/0600Z 22.5N  55.0W    55 KT
 
$$
FORECASTER RHOME
 

WTNT42 KNHC 261454
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER   7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
1100 AM EDT WED SEP 26 2007
 
KAREN CONTINUES TO SPIN UP AS A RAGGED EYE HAS BEEN SEEN
INTERMEDITENTLY THIS MORNING IN VISIBLE AND INFRARED IMAGERY. 
SUBJECTIVE DVORAK CLASSIFICATIONS AT 12Z ARE AT 4.0 AND 3.5 FROM
TAFB AND SAB...RESPECTIVELY.  AN AMSU PASS AT 08Z SUGGESTED AROUND
60 KT FROM THE CIMSS TECHNIQUE.  THE ADT...HOWEVER...ANALYSES KAREN
A BIT WEAKER AT ABOUT 50 KT.  GIVEN THE IMPROVED PRESENTATION SINCE
SYNOPTIC TIME...THE INITIAL INTENSITY OF KAREN IS SET AT 60 KT.

THE TROPICAL STORM IS MOVING AT 285/11 SOUTH OF A WEAK DEEP LEVEL
RIDGE.  AN UPPER TROUGH NORTHWEST OF KAREN IS FORECAST BY ALL
MODELS TO SLOWLY RETROGRADE AND PRODUCE ENOUGH OF A WEAKNESS IN THE
RIDGE TO ALLOW THE CYCLONE TO TURN TO THE NORTHWEST.  THE MODEL
GUIDANCE IS TIGHTLY CLUSTERED FOR THE FIRST 48 HOURS.  AT DAYS 3 TO
5...MOST MODELS SLOW KAREN'S PROGRESSION AS THE STEERING FLOW
SLACKENS.  THE MODELS DIFFER AT THE LONG RANGE ON BOTH THE STRENGTH
OF THE CYCLONE'S VORTEX AS WELL AS THE AMPLITUDE OF A SHORTWAVE
TROUGH NEAR BERMUDA.  THE TRACK FORECAST IS CLOSE TO THE CONSENSUS
OF DYNAMICAL MODELS WITH LESS WEIGHT BEING PLACED ON THE NORTHERN
OUTLYING NOGAPS MODEL.

GIVEN THAT THE CYCLONE IS INTENSIFYING...IT APPEARS THAT IT MAY
REACH HURRICANE INTENSITY SOON.  ENVIRONMENTAL CONDITIONS ARE
MIXED.  SSTS ARE A WARM 28C THOUGH THE SHEAR IS ANALYZED TO BE
ABOUT 15 KT OUT OF THE WEST.  THIS SHEAR DOES APPEAR TO BE
RESTRICTING THE WESTERN OUTFLOW OF KAREN.  THE SHEAR IS PREDICTED
BY ALL MODELS TO BE MAINTAINED OR EVEN GET STRONGER AT DAYS 3 TO 5
DUE TO THE INFLUENCE OF THE EARLIER MENTIONED UPPER LEVEL TROUGH. 
THE INTENSITY FORECAST BRINGS KAREN TO A HURRICANE SHORTLY...
LEVELING OFF IN A DAY OR TWO...AND THEN WEAKENING AT DAYS 4 AND 5. 
THIS IS IN AGREEMENT WITH SHIPS AND LGEM BUT STRONGER THAN HWRF AND
GFDL WHICH DO NOT BRING KAREN TO HURRICANE INTENSITY.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      26/1500Z 11.9N  42.9W    60 KT
 12HR VT     27/0000Z 12.6N  44.5W    65 KT
 24HR VT     27/1200Z 14.0N  46.8W    75 KT
 36HR VT     28/0000Z 15.5N  48.5W    75 KT
 48HR VT     28/1200Z 16.8N  50.0W    70 KT
 72HR VT     29/1200Z 19.0N  52.0W    65 KT
 96HR VT     30/1200Z 21.0N  54.0W    60 KT
120HR VT     01/1200Z 23.0N  55.5W    55 KT
 
$$
FORECASTER LANDSEA/PASCH
 

WTNT42 KNHC 262049
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER   8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
500 PM EDT WED SEP 26 2007
 
KAREN'S INTENSIFICATION...AT LEAST FOR THE TIME BEING...HAS
HALTED.  THE INTERMITTENT EYE IS NO LONGER PRESENT AND DEEP
CONVECTION IS MAINLY OCCURRING IN THE NORTHEASTERN SEMICIRCLE. 
SUBJECTIVE DVORAK ESTIMATES REMAIN AT 4.0 AND 3.5 FROM TAFB AND
SAB...THOUGH THE ADVANCED DVORAK TECHNIQUE CONTINUES TO SUGGEST AN
INTENSITY A BIT LOWER AT 50-55 KT.  AN 1835Z AMSU CIMSS ESTIMATE
ALSO GIVES A WIND OF 57 KT FOR KAREN. INITIAL INTENSITY IS KEPT AT
60 KT... THOUGH THIS MAY BE SOMEWHAT GENEROUS.

KAREN IS MOVING AT 295/10 UNDER THE INFLUENCE OF A LOW- TO MID-LEVEL
RIDGE TO ITS NORTH.  A TROUGH IN THE UPPER TROPOSPHERE LOCATED WEST
OF KAREN IS PREDICTED TO RETROGRADE WESTWARD AND INDUCE ENOUGH OF A
WEAKNESS IN THE RIDGE TO TURN KAREN TOWARD THE NORTHWEST BETWEEN
DAYS 3 AND 5.  THE MODEL CONSENSUS HAS SHIFTED SLIGHTLY TO THE WEST
IN THE 12Z RUNS.  THE TRACK FORECAST IS CONSISTENT WITH THAT
GUIDANCE EXCEPT TO PUT LESS WEIGHT ON THE GFS EARLY ON...DUE TO ITS
TOO RAPID INITIAL MOTION...AND THE NOGAPS AT DAYS 4 AND 5...DUE TO
ITS UNREALISTICALLY LARGE VORTEX AND NORTHWARD MOTION.

AS IN MANY CASES...THE INTENSITY FORECAST IS NOT CLEAR CUT.  KAREN
REMAINS OVER WARM 28C WATER AND HAS ABUNDANT MOISTURE NEARBY BUT IS
BEING IMPACTED BY MODERATE 15-20 KT WESTERLY SHEAR.  THE SHEAR
SHOULD CONTINUE AND PERHAPS BE ENHANCED DURING THE NEXT THREE DAYS. 
THE SHIPS AND LGM STATISTICAL GUIDANCE SUGGEST MODEST
INTENSIFICATION DURING THE NEXT DAY...BUT THIS MAY BE OVERLY
INFLUENCED BY THEIR PERSISTENCE PREDICTOR.  THE GFDL AND HWRF
DYNAMICAL GUIDANCE ARE LESS IMPRESSED WITH THE POTENTIAL FOR
INTENSIFICATION.  THE OFFICIAL INTENSITY FORECAST BRINGS KAREN TO A
HURRICANE...BUT JUST BARELY...IN A DAY BEFORE A GRADUAL WEAKENING
THEREAFTER.  HOWEVER...IF THE SHEAR CONTINUES TO ADVERSELY IMPACT
KAREN'S ABILITY TO MAINTAIN SYMMETRIC CONVECTION...THEN THE CYCLONE
MAY BE SIGNIFICANTLY WEAKER THAN PREDICTED HERE.

THE 12 FOOT SEAS RADII WERE ADJUSTED OUTWARD BASED UPON OBSERVATIONS
FROM NOAA BUOY 41041.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      26/2100Z 12.4N  43.6W    60 KT
 12HR VT     27/0600Z 13.2N  45.1W    60 KT
 24HR VT     27/1800Z 14.6N  47.2W    65 KT
 36HR VT     28/0600Z 15.9N  48.8W    65 KT
 48HR VT     28/1800Z 17.0N  50.1W    60 KT
 72HR VT     29/1800Z 19.0N  52.5W    55 KT
 96HR VT     30/1800Z 21.0N  55.0W    55 KT
120HR VT     01/1800Z 23.0N  57.0W    55 KT
 
$$
FORECASTER LANDSEA/PASCH
 

WTNT42 KNHC 270250
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
1100 PM EDT WED SEP 26 2007
 
A NOAA HURRICANE HUNTER PLANE HAS BEEN CONDUCTING A RESEARCH MISSION
THIS EVENING AND HAS FOUND AN UNUSUAL WIND STRUCTURE WITH KAREN.
SFMR DATA SHOW THAT THE STORM HAS A VERY LARGE WIND FIELD...WITH
ONE PEAK IN SURFACE WINDS ABOUT 105 NM AWAY FROM THE CENTER AND
ANOTHER ONE AT A MORE TYPICAL DISTANCE. IN ADDITION...DROPSONDE AND
SFMR DATA SUGGEST THAT THE FLIGHT LEVEL CENTER IS DISPLACED TO THE
NORTH AND EAST OF THE SURFACE CENTER...LIKELY DUE TO SOUTHWESTERLY
WIND SHEAR. THE MAXIMUM FLIGHT LEVEL WIND REPORTED WAS 69 KT...WITH
A PEAK SURFACE VALUE OF 62 KT REPORTED TWICE...NOT QUITE HURRICANE
STRENGTH. HOWEVER...GIVEN THE DEGRADED SATELLITE APPEARANCE FROM
EARLIER TODAY...KAREN WAS ALMOST CERTAINLY A HURRICANE THEN...AND
THIS LIKELIHOOD MAY BE REFLECTED IN THE FINAL BEST TRACK FOR THE
SYSTEM. AT THIS TIME...THE INITIAL INTENSITY IS HELD AT 60 KT FOR
THIS ADVISORY.

MODERATE TO STRONG SOUTHWESTERLY SHEAR FROM THE MID-OCEANIC TROUGH
IS AFFECTING KAREN AND THIS SHEAR IS FORECAST TO PERSIST OR EVEN
INTENSIFY OVER THE NEXT SEVERAL DAYS. IT IS HARD TO FORECAST
ANYTHING BUT SLOW WEAKENING GIVEN SUCH AN UNFAVORABLE ENVIRONMENT
AHEAD OF THE STORM...AND KAREN'S CHANCE TO INTENSIFY HAS PROBABLY
ENDED.  INITIALLY...MOST MODELS DO NOT WEAKEN THE SYSTEM VERY
MUCH...PERHAPS DUE TO THE LARGE STORM BEING ABLE TO MAINTAIN ITSELF
DESPITE THE SHEAR.  EVENTUALLY...MOST INTENSITY GUIDANCE WEAKEN THE
SYSTEM...AND THE OFFICIAL FORECAST IS CLOSER TO THE HWRF/GFDL
MODELS THAN THE SHIPS MODEL.  IT IS OF NOTE THAT THE GFDL EVEN
MAKES THIS SYSTEM A TROPICAL DEPRESSION BY THE END OF THE FORECAST.

MICROWAVE AND AIRCRAFT DATA HAVE PROVIDED A GOOD ESTIMATE OF THE
INITIAL MOTION...ABOUT 300/12.  THIS GENERAL MOTION SHOULD CONTINUE
FOR THE NEXT DAY OR SO AS WEAK RIDGING PERSISTS TO THE NORTH OF THE
STORM.  STEERING CURRENTS THEN WEAKEN AS A MIDDLE TO UPPER-LEVEL
TROUGH CREATES A WEAKNESS IN THE RIDGE.  THE MODELS THAT HAVE A
STRONG...VERTICALLY-STACKED REPRESENTATION OF KAREN...E.G. THE
ECMWF/GFDN/HWRF/NOGAPS SOLUTIONS..SHOW THE STORM MOVING MORE TO THE
NORTHWEST OR NORTH-NORTHWEST IN RESPONSE TO THE TROUGH.  HOWEVER
THE GFDL/GFS/UKMET MODELS GENERALLY HAVE A WEAKER STORM AT THAT
TIME...AND SHOW LITTLE REACTION TO THE TROUGH AND JUST SLOW THE
STORM AS IT ENTERS THE AREA OF LIGHTER STEERING CURRENTS.  THE
OFFICIAL FORECAST FAVORS THE LEFTWARD SOLUTION AT THIS TIME AND IS
ADJUSTED WESTWARD OF THE PREVIOUS FORECAST.  
 
THE WIND RADII WERE EXPANDED THANKS TO SFMR DATA...QUIKSCAT...AND
NOAA BUOY 41041.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      27/0300Z 13.0N  45.1W    60 KT
 12HR VT     27/1200Z 13.9N  46.7W    60 KT
 24HR VT     28/0000Z 15.2N  48.7W    60 KT
 36HR VT     28/1200Z 16.5N  50.5W    55 KT
 48HR VT     29/0000Z 17.5N  51.9W    50 KT
 72HR VT     30/0000Z 19.4N  54.7W    45 KT
 96HR VT     01/0000Z 21.0N  57.0W    45 KT
120HR VT     02/0000Z 22.5N  58.5W    45 KT
 
$$
FORECASTER BLAKE
 

WTNT42 KNHC 270841
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER  10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
500 AM EDT THU SEP 27 2007
 
THE STRONG SOUTHWESTERLY SHEAR HAS TAKEN A TOLL ON KAREN THIS
MORNING.  RECENT TRMM AND AMSU-B MICROWAVE PASSES SUGGEST THAT THE
LOW-LEVEL CIRCULATION CENTER HAS CONTINUED TO BECOME DECOUPLED FROM
THE MID- AND UPPER-LEVELS.  CONVENTIONAL SATELLITE IMAGERY INDICATE
AN ELONGATED AREA OF DEEP CONVECTION ABOUT 60 N MI NORTHEAST OF THE
CENTER...EXTENDING NORTHEASTWARD FOR A COUPLE OF HUNDRED MILES. 
DVORAK SATELLITE INTENSITY CLASSIFICATIONS ARE 3.0/4.0 FROM TAFB AND
3.0/3.5 FROM SAB.  TAKING A BLEND OF THE INTENSITY ESTIMATES ALONG
WITH THE CURRENT SATELLITE APPEARANCE...THE INITIAL INTENSITY HAS
BEEN LOWERED TO 55 KT.  

THE INITIAL MOTION IS SLIGHTLY FASTER...ABOUT 300/13.  A WEAK RIDGE
NORTH OF THE CYCLONE IS EXPECTED TO PERSIST FOR THE NEXT DAY OR SO
WHICH SHOULD RESULT IN A GENERAL WEST-NORTHWESTWARD MOTION.  AFTER
24- TO 36-HOURS...LARGE DIVERGENCE IN MODEL GUIDANCE EXISTS WHEN A
DEEP MID- TO UPPER-LEVEL TROUGH APPROACHES FROM THE WEST.  ONE
GROUP OF MODELS MAINTAINS KAREN AS A STRONGER CYCLONE AND TAKES THE
SYSTEM TOWARD THE NORTHWEST IN RESPONSE TO THE TROUGH.  THE SECOND
GROUP FORECAST KAREN AS A MUCH WEAKER SYSTEM AND STEER IT WITH THE
LOW-LEVEL FLOW.  THE OFFICIAL TRACK FORECAST FOLLOWS THE LATTER
SOLUTION...WHICH IS CLOSE WITH THE GFS AS WELL AS THE PREVIOUS
ADVISORY PACKAGE. 

THE SHEAR IS EXPECTED TO REMAIN STRONG FOR THE NEXT 72 HOURS OR
SO...WHICH WOULD LEAD TO A CONTINUED WEAKENING TREND OF THE
CYCLONE.  BY DAYS 4 AND 5...MOST OF THE MODEL GUIDANCE FORECASTS
THE SHEAR TO DECREASE.  HOWEVER...THE DECREASED SHEAR APPEARS TO BE
RESULTANT OF KAREN APPROACHING THE AXIS OF THE AFOREMENTIONED
TROUGH...WHICH WOULD NOT BE CONDUCIVE FOR MUCH STRENGTHENING
EITHER.  SIMILAR TO THE PREVIOUS FORECAST...THE OFFICIAL INTENSITY
FORECAST CALLS FOR GRADUAL WEAKENING THROUGH FIVE DAYS.  BUT...IF
THE LOW-LEVEL CIRCULATION CENTER BECOMES FURTHER SEPARATED FROM THE
DEEP CONVECTION...THE CYCLONE COULD WEAKER FASTER THAN INDICATED. 

NOAA BUOY 41041 REPORTED A MAXIMUM 1-MINUTE WIND OF 43 KT AROUND
0700 UTC...ABOUT 75 N MI NORTH OF THE ESTIMATED CENTER LOCATION.  

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      27/0900Z 13.6N  46.6W    55 KT
 12HR VT     27/1800Z 14.6N  48.3W    50 KT
 24HR VT     28/0600Z 15.8N  50.2W    50 KT
 36HR VT     28/1800Z 16.9N  51.9W    45 KT
 48HR VT     29/0600Z 18.1N  53.7W    45 KT
 72HR VT     30/0600Z 20.0N  56.0W    40 KT
 96HR VT     01/0600Z 21.5N  57.5W    40 KT
120HR VT     02/0600Z 23.0N  59.0W    40 KT
 
$$
FORECASTER MAINELLI
 

WTNT42 KNHC 271434
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER  11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
1100 AM EDT THU SEP 27 2007
 
THIS MORNING'S NOAA P-3 HURRICANE HUNTER EXPERIMENTAL MISSION
REVEALED AN SFMR MAXIMUM SURFACE WIND OF 56 KT...A MAXIMUM FLIGHT
LEVEL WIND OF 57 KT ABOUT 120 NM EAST OF THE EXPOSED SURFACE
CIRCULATION...AND ANOTHER PEAK WIND ABOUT 20 NM NORTHWEST OF THE
CENTER.  THE WIND PROFILE RESEMBLES LAST NIGHT'S MISSION WHICH ALSO
INDICATED AN UNUSUAL HORIZONTAL WIND PROFILE.  BASED ON THE SFMR
DATA...THE INITIAL INTENSITY REMAINS AT 55 KT.
 
THE 20 TO 30 KT SOUTHWESTERLY SHEAR IS EXPECTED TO PERSIST DURING
THE NEXT 3 DAYS...WITH ONLY A SLIGHT DECREASE THROUGH THE REMAINING
PORTION OF THE FORECAST.  THIS IS IN AGREEMENT WITH THE GLOBAL
MODELS...SHIPS...AND THE LOGISTICAL GROWTH EQUATION MODEL.  THE
OFFICIAL FORECAST CALLS FOR GRADUAL WEAKENING THROUGH THE ENTIRE
PERIOD...BUT MAINTAINING TROPICAL STORM STRENGTH.
 
THE INITIAL MOTION IS 295/10.  A DEEP-LAYERED SUBTROPICAL RIDGE
NORTH OF THE CYCLONE SHOULD INDUCE A WEST-NORTHWESTWARD MOTION
DURING THE NEXT DAY OR SO.  AFTERWARD...THERE ARE GENERALLY TWO
DYNAMICAL MODEL CLUSTERS INDICATING TWO POSSIBLE SOLUTIONS.  THE
ECMWF AND THE GFS SHOW MOTION INDICATIVE OF THE LOW- TO MID-LEVEL
STEERING FLOW...WHILE THE REMAINING MODELS REFLECT A STRONGER
TROPICAL CYCLONE AND SUGGEST A MORE NORTHWESTWARD MOTION INFLUENCED
BY AN AMPLIFYING MID- TO UPPER TROUGH.  THE OFFICIAL FORECAST IS
BASED ON THE GFS AND ECMWF SOLUTION AND IS VERY CLOSE TO THE
PREVIOUS ADVISORY.
 
NOAA BUOY 41041 REPORTED A MAXIMUM 1-MINUTE WIND OF 37 KT AROUND
1300 UTC...ABOUT 80 N MI EAST-NORTHEAST OF THE ESTIMATED CENTER
LOCATION.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      27/1500Z 13.7N  47.3W    55 KT
 12HR VT     28/0000Z 14.7N  48.7W    50 KT
 24HR VT     28/1200Z 16.0N  50.6W    45 KT
 36HR VT     29/0000Z 17.0N  52.0W    45 KT
 48HR VT     29/1200Z 18.0N  53.3W    45 KT
 72HR VT     30/1200Z 19.5N  55.5W    40 KT
 96HR VT     01/1200Z 21.0N  57.0W    40 KT
120HR VT     02/1200Z 23.0N  58.5W    40 KT
 
$$
FORECASTER ROBERTS/AVILA
 

WTNT42 KNHC 272035
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER  12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
500 PM EDT THU SEP 27 2007
 
PERSISTENTLY STRONG SOUTHWESTERLY SHEAR CONTINUES TO AFFECT THE
TROPICAL CYCLONE...DISPLACING THE DEEP CONVECTION FROM THE
CIRCULATION CENTER.  ALTHOUGH DVORAK SATELLITE INTENSITY ESTIMATES
FROM TAFB AND SAB HAVE DECREASED TO 45 KT...SOME RECENT DEEP
CONVECTIVE BURSTS NEAR THE CENTER SUGGEST A SLIGHTLY HIGHER
INTENSITY.  THEREFORE...THE INITIAL WIND SPEED IS SET TO 50 KT.
 
THE INTENSITY FORECAST IS RELATIVELY STRAIGHTFORWARD THROUGH DAY
5...INDICATING GRADUAL WEAKENING.  HOWEVER...LARGE-SCALE DYNAMICAL
MODELS...SHIPS...AND THE LGEM ARE NOW SUGGESTING THAT THE SHEAR
WILL BEGIN TO WEAKEN AROUND THE 96 TO 120 HR PERIOD WHEN THE
TROPICAL CYCLONE REACHES THE UPPER TROUGH AXIS.  CONSEQUENTLY...
SLIGHT INTENSIFICATION IN THE LATTER PART OF THE PERIOD IS
POSSIBLE...ALBEIT NOT INDICATED IN THE OFFICIAL FORECAST AT THIS
TIME.
 
KAREN IS MOVING AT 305/11...WITH THIS GENERAL MOTION CONTINUING
DURING THE NEXT 2 DAYS OR SO AS KAREN PROPAGATES WITHIN THE
DEEP-LAYERED FLOW ASSOCIATED WITH THE SUBTROPICAL RIDGE TO THE
NORTH.  THROUGH THE REMAINING PORTION OF THE FORECAST...THE
DYNAMICAL MODELS ARE AGREEING IN BUILDING THE MID- LEVEL RIDGE MORE
TOWARD THE NORTHWEST OF THE CYCLONE CAUSING KAREN TO TURN MORE
WEST-NORTHWESTWARD.  THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS
PACKAGE AND IS BASED ON A CONSENSUS OF THE MODELS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      27/2100Z 14.3N  48.5W    50 KT
 12HR VT     28/0600Z 15.5N  49.8W    45 KT
 24HR VT     28/1800Z 16.8N  51.5W    45 KT
 36HR VT     29/0600Z 17.8N  52.8W    45 KT
 48HR VT     29/1800Z 18.7N  54.0W    45 KT
 72HR VT     30/1800Z 20.5N  55.5W    40 KT
 96HR VT     01/1800Z 22.5N  56.5W    40 KT
120HR VT     02/1800Z 24.0N  58.5W    40 KT
 
$$
FORECASTER ROBERTS/AVILA
 

WTNT42 KNHC 280249
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER  13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
1100 PM EDT THU SEP 27 2007
 
A LARGE BURST OF DEEP CONVECTION FORMED NEAR THE CENTER OF KAREN
TONIGHT.  HOWEVER...THUNDERSTORMS ARE ALREADY DIMINISHING AND
SOUTHWESTERLY WIND SHEAR CONTINUES TO HINDER ANY DEVELOPMENT.
DVORAK SATELLITE ESTIMATES ARE A LITTLE HIGHER THAN EARLIER...BUT
ARE STILL BELOW THE PREVIOUS INITIAL INTENSITY.  WINDS WILL BE KEPT
AT 50 KT FOR THIS ADVISORY.
 
THE INITIAL MOTION ESTIMATE OF 295/12 IS A BLEND OF THE EXTRAPOLATED
MOVEMENT FROM THE LAST AVAILABLE VISIBLE IMAGES AND A RECENT SSMIS
MICROWAVE PASS.  A SMALL RIGHTWARD BEND TO THE TRACK IS EXPECTED
OVER THE NEXT COUPLE OF DAYS AS LOW TO MID-LEVEL RIDGING TO THE
NORTH OF THE SYSTEM SLOWLY WEAKENS.  THE RIDGE IS EXPECTED TO BE
THE WEAKEST IN ABOUT 48-72 HOURS DUE TO A MIDDLE-LATITUDE TROUGH IN
THE CENTRAL ATLANTIC AND COULD STEER THE STORM MORE TO THE
NORTH-NORTHWEST AT THAT TIME.  HOWEVER...THIS TROUGH IS NOT EXPECTED
TO BE STRONG ENOUGH TO TURN THE STORM OUT TO SEA AND ALL MODELS
BUILD RIDGING TO THE NORTH OF THE STORM...FORCING A WEST-NORTHWEST
TURN AT THE END OF THE FORECAST PERIOD.  THE OFFICIAL FORECAST IS
SHIFTED WESTWARD WITH THIS PACKAGE IN BEST AGREEMENT WITH THE
GFS/ECMWF MODELS AND IS ON THE LEFT SIDE OF THE GUIDANCE ENVELOPE. 
IF THE STORM WEAKENS MORE THAN EXPECTED...THIS FORECAST MAY HAVE TO
BE ADJUSTED FARTHER TO THE WEST..ESPECIALLY IN THE SHORT-TERM.
 
KAREN SHOULD BE IN AN ENVIRONMENT OF STRONG WESTERLY SHEAR CAUSED BY
THE MID-OCEANIC TROUGH FOR AT LEAST THE NEXT 48-72 HOURS. THIS
PATTERN FAVORS AT LEAST SLOW WEAKENING DURING THAT TIME. HOWEVER...
IF THE STORM SURVIVES THE SHEAR...GLOBAL MODELS SUGGEST THAT AN
OPPORTUNITY FOR RESTRENGTHENING COULD OCCUR IN THE LONG-RANGE AS
THE TROUGH WEAKENS AND IS REPLACED BY RIDGING. RELIABLE INTENSITY
GUIDANCE RESPONDS TO THIS CHANGE IN SHEAR AND SHOWS AN INCREASE IN
STRENGTH BEYOND 3 DAYS. IN FACT...THE GFDL/HWRF MODELS ACTUALLY
MAKE KAREN A HURRICANE IN 5 DAYS. DUE TO LARGE UNCERTAINTY AT THE
LONGER-RANGES...THE OFFICIAL FORECAST WILL ONLY BE SLIGHTLY
INCREASED...AND COULD BE CONSERVATIVE IF THE STORM ENDURES THE NEXT
48 HOURS OR SO.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      28/0300Z 14.8N  49.5W    50 KT
 12HR VT     28/1200Z 15.7N  50.9W    45 KT
 24HR VT     29/0000Z 16.9N  52.5W    45 KT
 36HR VT     29/1200Z 18.0N  53.8W    40 KT
 48HR VT     30/0000Z 19.2N  54.8W    40 KT
 72HR VT     01/0000Z 21.0N  56.0W    40 KT
 96HR VT     02/0000Z 22.5N  57.5W    45 KT
120HR VT     03/0000Z 23.5N  59.5W    50 KT
 
$$
FORECASTER BLAKE
 

WTNT42 KNHC 280857
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER  14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
500 AM EDT FRI SEP 28 2007
 
THE SATELLITE PRESENTATION OF KAREN HAS DETERIORATED DURING THE LAST
SIX HOURS...AND THE BURST OF DEEP CONVECTION THAT HAD PREVIOUSLY
OBSCURED THE LOW-LEVEL CENTER HAS WEAKENED.  LATEST CONVENTIONAL
AND MICROWAVE IMAGERY SUGGESTS THAT THE LOW-LEVEL CIRCULATION
CENTER IS TO THE SOUTH OF THE PREVIOUS ADVISORY POSITION...AND THE
INITIAL POSITION HAS BEEN ADJUSTED ACCORDINGLY.  CURRENT DVORAK
INTENSITY CLASSIFICATIONS REMAIN AT 35 KT FROM BOTH TAFB AND
SAB...AND THE INITIAL INTENSITY HAS BEEN LOWERED TO A POSSIBLY
GENEROUS 40 KT.
 
AS A RESULT OF THE RELOCATION OF THE CENTER...THE INITIAL MOTION IS
AN UNCERTAIN 290/9.  KAREN IS EXPECTED TO MOVE ON A GENERAL
WEST-NORTHWESTWARD TO NORTHWESTWARD TRACK FOR THE NEXT TWO TO THREE
DAYS IN RESPONSE TO A LOW- TO MID-LEVEL RIDGE TO THE NORTH OF THE
CYCLONE.  IN 48-72 HOURS...A MID-LATITUDE TROUGH IS EXPECTED TO
APPROACH THE CYCLONE FROM THE WEST...AND IT IS DIFFICULT TO
DETERMINE HOW MUCH OF A NORTHWARD STEERING INFLUENCE THE TROUGH
WILL HAVE ON KAREN.  BY DAY 4...MOST OF THE GUIDANCE AGREES THAT A
MORE WEST-NORTHWESTWARD TO WESTWARD MOTION COULD OCCUR AS THE
TROUGH MOVES EAST AND HIGH PRESSURE BUILDS BACK IN TO THE NORTH OF
THE CYCLONE.  THE OFFICIAL TRACK FORECAST IS TO THE WEST OF THE
PREVIOUS ADVISORY...PRIMARILY DUE TO THE INITIAL RELOCATION...AND
FOLLOWS MOST CLOSELY WITH THE GFDL AND GFS GUIDANCE.
 
THE STRONG WESTERLY SHEAR CURRENTLY AFFECTING THE CYCLONE IS
EXPECTED TO PERSIST FOR THE NEXT 48 HOURS OR SO.  ONCE THE
AFOREMENTIONED MID-LATITUDE TROUGH MOVES EAST OF KAREN... THE SHEAR
IS FORECAST TO RELAX AS RIDGING TO THE NORTH RETURNS.  IF KAREN IS
ABLE TO SURVIVE THE SHEAR FOR THE NEXT 48 HOURS...  RESTRENGTHENING
COULD OCCUR IN THE LATER FORECAST PERIODS.  TAKING A BLEND OF THE
GFDL...HWRF...AND SHIPS INTENSITY GUIDANCE YIELDS THE OFFICIAL
INTENSITY FORECAST FOR THIS ADVISORY.
 
IT SHOULD BE NOTED THAT THERE ARE LARGE UNCERTAINTIES IN BOTH THE
TRACK AND INTENSITY AT THE LONGER FORECAST PERIODS.
 
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      28/0900Z 14.1N  49.8W    40 KT
 12HR VT     28/1800Z 14.8N  50.9W    35 KT
 24HR VT     29/0600Z 16.0N  52.4W    35 KT
 36HR VT     29/1800Z 17.3N  53.8W    35 KT
 48HR VT     30/0600Z 18.5N  55.0W    35 KT
 72HR VT     01/0600Z 20.5N  56.4W    40 KT
 96HR VT     02/0600Z 22.0N  57.5W    45 KT
120HR VT     03/0600Z 22.5N  60.0W    50 KT
 
$$
FORECASTER MAINELLI
 

WTNT42 KNHC 281446
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER  15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
1100 AM EDT FRI SEP 28 2007
 
VISIBLE IMAGERY SUGGESTS THAT THE WEAKENING CIRCULATION OF KAREN HAS
MOVED ERRATICALLY THIS MORNING...BUT NOW APPEARS TO BE RETURNING TO
A PREVIOUS WEST-NORTHWESTWARD MOTION.  AN EARLIER 0910Z QUIKSCAT
OVERPASS INDICATED THAT THERE WAS A SMALL AREA OF BELIEVABLE
FLAGGED 40 KT WINDS IN THE NORTHEAST QUADRANT.  BUT SINCE
THEN...THAT CONVECTIVE AREA CONTAINING THE COLDEST TOPS HAS
DIMINISHED CONSIDERABLY.  BASED ON THE QUIKSCAT INTERPRETATION AND
CURRENT SATELLITE INTENSITY ESTIMATES OF 35 KT...THE INITIAL
INTENSITY IS LOWERED TO 35 KT...AND THIS COULD BE GENEROUS.
 
PERSISTENTLY STRONG SOUTHWESTERLY SHEAR IS EXPECTED TO AFFECT KAREN
DURING THE NEXT 72 HOURS OR SO.  THEREAFTER...THE INTENSITY GUIDANCE
AGREES IN BRINGING UNFAVORABLE UPPER-LEVEL NORTHWESTERLY WINDS OVER
THE SYSTEM.  THE OFFICIAL FORECAST INDICATES WEAKENING TO A
DEPRESSION IN 12 HOURS...FOLLOWING THE SHIPS AND LGEM.
AFTERWARD...BECAUSE OF THE POTENTIAL OF INTERMITTENT BURSTS OF DEEP
CONVECTION NEAR THE CENTER...THE FORECAST SHOWS LITTLE CHANGE IN
STRENGTH.  HOWEVER...KAREN COULD BECOME A REMNANT LOW IN 36
HOURS...AS INDICATED BY BOTH AFOREMENTIONED INTENSITY MODELS.  IN
PREVIOUS RUNS...DESPITE THE OBVIOUS UNFAVORABLE UPPER LEVEL
WIND ENVIRONMENT...SOME DYNAMICAL MODELS SUGGESTED SIGNIFICANT
STRENGTHENING.  HOWEVER...IN THE LATEST RUNS...THE GFS WEAKENS KAREN
AND THIS IS A MORE REALISTIC SCENARIO.  ECMWF AND GFDL INSIST ON
STRENGTHENING.  WE SHALL SEE IN THE NEXT RUN IF THESE MODELS COME TO
AN AGREEMENT WITH THE GFS.
 
INITIAL MOTION IS ESTIMATED AT 295/8.  A LOW- TO MID LEVEL
TROPOSPHERIC SUBTROPICAL RIDGE TO THE NORTH OF KAREN SHOULD
MAINTAIN A WEST-NORTHWESTWARD MOTION DURING THE NEXT 2 DAYS. 
AFTERWARD...A DEVELOPING WEAKNESS IN THE RIDGE NORTHWEST OF THE
CYCLONE SHOULD TEMPORARILY INDUCE A MORE NORTHWESTWARD MOTION.
AROUND THE 96 HOUR PERIOD...ALL OF THE DYNAMICAL MODELS ARE
INDICATING THAT THE TROUGH WILL FILL AND MOVE NORTHEAST ALLOWING A
MID- LEVEL HIGH TO BUILD SOUTHEAST OF BERMUDA.  THIS CHANGE IN THE
STEERING PATTERN SHOULD CAUSE KAREN TO TURN MORE TO THE WEST...IF
THE CYCLONE SURVIVES FOR THAT LONG OF A PERIOD.  THE OFFICIAL TRACK
FORECAST IS CLOSE TO THE PREVIOUS PACKAGE AND IS BASED ON A BLEND OF
THE MODEL CONSENSUS...AND HEDGES TOWARD THE SHALLOW MEAN LAYER
BAM....SINCE THE KAREN IS FORECAST TO WEAKEN.

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      28/1500Z 15.1N  49.2W    35 KT
 12HR VT     29/0000Z 15.5N  50.5W    30 KT
 24HR VT     29/1200Z 16.6N  52.0W    30 KT
 36HR VT     30/0000Z 17.6N  53.3W    30 KT
 48HR VT     30/1200Z 18.5N  54.6W    30 KT
 72HR VT     01/1200Z 20.0N  56.5W    30 KT
 96HR VT     02/1200Z 21.5N  58.0W    30 KT
120HR VT     03/1200Z 22.0N  60.0W    30 KT
 
$$
FORECASTER ROBERTS
 

WTNT42 KNHC 282032
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER  16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
500 PM EDT FRI SEP 28 2007
 
NOT SURPRISINGLY...THIS AFTERNOON...KAREN IS ATTEMPTING TO MAKE A
COMEBACK.  DEEP CONVECTION IS DEVELOPING JUST TO THE NORTHEAST OF
THE CENTER.  A 1328Z ASCAT OVERPASS HAPPENED TO CAPTURE THE
MAJORITY OF THE SYSTEM AND INDICATED 30 KT WINDS OVER THE NORTHEAST
QUADRANT.  HOWEVER...THIS PARTICULAR PASS WAS A FEW HOURS BEFORE
THE CONVECTIVE CANOPY BEGAN TO EXPAND AND INTENSIFY.  THE DVORAK
SATELLITE CURRENT INTENSITY ESTIMATES HAVE INCREASED TO 35 KT AND
THE INITIAL INTENSITY REMAINS AT 35 KT.
 
THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS PACKAGE
AND IS A BLEND OF THE SHIPS AND THE LGEM...INDICATING WEAKENING
UNDER STRONG UPPER LEVEL SOUTHWESTERLY FLOW DURING THE NEXT 24
HOURS...THEN LITTLE CHANGE THROUGH DAY 5...DUE TO AN UNFAVORABLE
UPPER WIND ENVIRONMENT.
 
INITIAL MOTION IS ESTIMATED AT 310/10.  THE UNPREDICTED TEMPORARY
NORTHWARD MOTION COULD BE DUE TO A COMBINATION OF SLIGHT
STRENGTHENING OF THE LOW- LEVEL RIDGE BETWEEN TROPICAL DEPRESSION
14 AND KAREN AND SOUTHERLY FLOW WITH A TROUGH WEST OF THE CYCLONE. 
CONSEQUENTLY...IT IS UNCLEAR IF OR WHEN THE SYSTEM WILL RETURN TO
ITS PREVIOUS NORTHWESTWARD MOTION THAT THE DYNAMICAL MODELS
CONTINUE TO SUGGEST.  THEREFORE...BASED ON A BLEND OF THE
LARGE-SCALE MODELS AND THE GFDL...THE OFFICIAL FORECAST
SHOWS A TURN BACK MORE TO THE NORTHWEST DURING THE NEXT 12
HOURS.  THE MODELS HAVE SPLIT INTO TWO POSSIBLE SCENARIOS
AGAIN...WITH THE GFS AND THE HWRF INDICATING MORE OF A NORTHWARD
MOTION AT THE END OF THE FORECAST PERIOD IN RESPONSE TO AN
APPROACHING MID-LATITUDE TROUGH FROM THE NORTHWEST.  THE OTHER
CLUSTER CONSISTS OF THE UKMET...ECMWF...AND NOGAPS WHICH REFLECTS A
TURN MORE TOWARD THE WEST-NORTHWEST.  BASED ON THE CONSTANT
INCONSISTENCIES FROM ONE MODEL RUN TO THE OTHER...THE OFFICIAL
FORECAST IS BASED ON A DYNAMICAL MODEL CONSENSUS AND IS ADJUSTED TO
THE RIGHT OF THE PREVIOUS FORECAST DUE TO THIS MORNING'S NORTHWARD
JOG.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      28/2100Z 16.4N  49.9W    35 KT
 12HR VT     29/0600Z 17.1N  50.9W    35 KT
 24HR VT     29/1800Z 18.2N  52.4W    30 KT
 36HR VT     30/0600Z 19.2N  53.7W    30 KT
 48HR VT     30/1800Z 20.3N  55.0W    30 KT
 72HR VT     01/1800Z 22.5N  57.5W    30 KT
 96HR VT     02/1800Z 24.0N  59.5W    30 KT
120HR VT     03/1800Z 25.5N  61.5W    30 KT
 
$$
FORECASTER ROBERTS
 

WTNT42 KNHC 290231
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER  17
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
1100 PM EDT FRI SEP 28 2007
 
DETERMINING THE ACTUAL CENTER OF KAREN HAS BEEN A SIGNIFICANT
CHALLENGE THIS EVENING.  IT APPEARS THAT THE EARLIER EXPOSED
CENTER...NOW MOVING NORTHWESTWARD...HAS BECOME JUST ANOTHER SWIRL
AROUND AN ELONGATED LOW-LEVEL CIRCULATION FARTHER TO THE SOUTHWEST. 
A RECENT QUIKSCAT PASS SUPPORTS THIS ASSESSMENT...SHOWING A LARGE
AREA OF LIGHT WINDS SOUTHWEST OF THE OLD CENTER.  THUS...THE CENTER
IS RELOCATED WESTWARD TO THE LIGHTER WIND AREA AS SUGGESTED BY
QUIKSCAT AND NIGHT VISIBLE SATELLITE IMAGES.  OVERALL..THE SYSTEM
REMAINS VERY DISORGANIZED DUE TO FEROCIOUS WESTERLY SHEAR...WITH
THUNDERSTORMS MOSTLY IN THE EASTERN SEMICIRCLE.  EVEN WITH THE
DISHEVELED SATELLITE APPEARANCE...QUIKSCAT SUPPORTS AN INTENSITY OF
AT LEAST 35 KT...AND THE INITIAL INTENSITY WILL BE HELD AT 35 KT.
 
STRONG WESTERLY OR SOUTHWESTERLY SHEAR IS FORECAST TO CONTINUE FOR
ABOUT THE NEXT 48 HOURS AND SHOULD INDUCE WEAKENING OF KAREN. THE
INTENSITY FORECAST FOR THIS TIME SHOWS THE SYSTEM BARELY HANGING ON
AS A TROPICAL CYCLONE....AND DISSIPATION IS POSSIBLE. 
THEREAFTER...THE GFS AND UKMET MODELS CARVE OUT A PIECE OF THE
MID-OCEANIC TROUGH INTO A CUT-OFF LOW THAT MOVES SOUTHWARD NEAR AND
THEN TO THE SOUTH OF WHATEVER REMAINS OF KAREN. THIS EVOLUTION
COULD PLACE THE SYSTEM IN A MORE FAVORABLE LOCATION FOR SOME
STRENGTHENING WITH MORE EASTERLY FLOW ALOFT TO THE NORTH OF THE
CUT-OFF LOW. THE GFDL RESPONDS TO THESE CONDITIONS BY MAKING KAREN
A HURRICANE IN ABOUT 4 DAYS. HOWEVER...OTHER MODELS KEEP MODERATE
TO STRONG SHEAR OVER THE SYSTEM FOR A LONGER PERIOD OF TIME AND
THIS SOLUTION WOULD FAVOR DISSIPATION.  UNTIL THERE IS SOME CLARITY
ON IF THE SYSTEM WILL SURVIVE THE SHEAR...I'M INCLINED TO MAKE
LITTLE CHANGE TO THE LONG-TERM FORECAST AND KEEP THE CYCLONE AS A
TROPICAL DEPRESSION.  OBVIOUSLY...FORECAST CONFIDENCE IS EXTREMELY
LOW TONIGHT.
 
TO SMOOTH OUT THE IRREGULAR MOTION DURING THE PAST 24 HOURS... A
LONG-TERM MOVEMENT WILL BE USED AS THE INITIAL MOTION...ESTIMATED
AT 295/8.  A TRACK BETWEEN WEST-NORTHWEST AND NORTHWEST IS EXPECTED
FOR THE NEXT FEW DAYS AS KAREN MOVES AROUND THE SOUTHWESTERN SIDE
OF A LOW TO MID-LEVEL RIDGE OVER THE CENTRAL ATLANTIC OCEAN. 
THEREAFTER A TURN TO A MORE WESTWARD MOTION IS POSSIBLE DUE TO
RISING HEIGHTS TO THE NORTH OF KAREN.  NUMERICAL GUIDANCE HAS
BEEN MUCH TOO FAR TO THE RIGHT WITH THIS SYSTEM AND...GIVEN THE
CONTINUED WEAK INTENSITY OF THE STORM...THE NHC FORECAST WILL LIE
ON THE LEFT SIDE OF THE GUIDANCE ENVELOPE SIMILAR TO THE 18Z GFS. 
THE LARGE WESTWARD SHIFT AT 4 AND 5 DAYS IS MOSTLY DUE TO THE
CENTER REFORMATION...AND NOT A HUGE CHANGE IN THE MODEL GUIDANCE.  
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/0300Z 16.2N  51.9W    35 KT
 12HR VT     29/1200Z 17.0N  53.2W    35 KT
 24HR VT     30/0000Z 18.2N  54.9W    30 KT
 36HR VT     30/1200Z 19.5N  56.3W    25 KT
 48HR VT     01/0000Z 20.7N  57.6W    25 KT
 72HR VT     02/0000Z 23.0N  60.0W    30 KT
 96HR VT     03/0000Z 24.5N  62.5W    30 KT
120HR VT     04/0000Z 25.5N  64.5W    30 KT
 
$$
FORECASTER BLAKE
 

WTNT42 KNHC 290845
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER  18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
500 AM EDT SAT SEP 29 2007

ONCE AGAIN...LOCATING THE PRIMARY LOW-LEVEL CIRCULATION OF KAREN
CONTINUES TO BE QUITE A CHALLENGE THIS MORNING.  BOTH CONVENTIONAL
AND MICROWAVE IMAGERY SUGGEST THAT THE CIRCULATION HAS BECOME
ELONGATED WITH SEVERAL SMALLER SWIRLS EMBEDDED WITHIN THE LARGER
CIRCULATION.  AS A RESULT...THE INITIAL POSITION IS BASED MOSTLY ON
AN EXTRAPOLATION FROM THE PREVIOUS ADVISORY.  KAREN REMAINS IN AN
EXTREMELY HOSTILE UPPER-LEVEL ENVIRONMENT WITH 40-45 KTS OF
WESTERLY SHEAR...WHICH IS SIGNIFICANTLY DISRUPTING CONVECTIVE
ACTIVITY.  DVORAK DATA T-NUMBERS AND CURRENT INTENSITY ESTIMATES
ARE 30 KT AND 35 KT RESPECTIVELY FROM BOTH TAFB AND SAB...AND THE
INITIAL INTENSITY IS KEPT GENEROUSLY AT 35 KTS. 

THE INTENSITY FORECAST REMAINS PROBLEMATIC.  THE STRONG WESTERLY
SHEAR IS EXPECTED TO PERSIST FOR AT LEAST THE NEXT 24 HOURS...AND
IT IS DIFFICULT TO SAY WHETHER OR NOT KAREN WILL SURVIVE SUCH AN
UNFAVORABLE ENVIRONMENT.  BOTH THE GFDL AND HWRF MODEL GUIDANCE
SUGGEST THAT THE SHEAR WILL LESSEN IN ABOUT 72 HOURS...PROVIDING A
MORE FAVORABLE ENVIRONMENT FOR THE CYCLONE TO STRENGTHEN.  IN
FACT...THE GFDL TAKES KAREN TO 80 KT IN FOUR DAYS AND THE HWRF
MODEL INTENSIFIES KAREN TO AROUND 100 KT BY DAY 5.  SINCE SO MUCH
UNCERTAINTY EXISTS IN KAREN SURVIVING THE NEXT 24 TO 36 HOURS...I
WILL MAINTAIN CONTINUITY AND FORECAST KAREN AS A DEPRESSION THROUGH
FIVE DAYS.  THIS INTENSITY FORECAST IS ALSO ALIGNED WITH THE LGE
MODEL. 

AN 18-24 HOUR MOVEMENT OF THE SYSTEM YIELDS AN ESTIMATED MOTION OF
300/10.  KAREN IS FORECAST TO CONTINUE TO MOVE ON A GENERAL WEST-
NORTHWESTWARD TO NORTHWESTWARD TRACK AROUND THE SOUTHWESTERN
PERIPHERY OF A LOW-MID LEVEL RIDGE.  IT APPEARS FROM THE MODEL
GUIDANCE THAT THE MID-LATITUDE TROUGH CURRENTLY LOCATED JUST OFF
THE EAST COAST OF THE UNITED STATES WILL BYPASS KAREN IN THE NEXT
COUPLE OF DAYS. THEREAFTER...THE RIDGE TRIES TO BUILD BACK IN
STEERING KAREN ON A MORE WEST-NORTHWESTWARD TO WESTWARD TRACK.  THE
OFFICIAL TRACK FORECAST IS ESSENTIALLY AN UPDATE OF THE PREVIOUS
PACKAGE AND REMAINS CLOSE TO THE GFS SOLUTION...BUT SOUTH OF THE
MODEL CONSENSUS.  
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/0900Z 16.6N  52.9W    35 KT
 12HR VT     29/1800Z 17.4N  54.3W    30 KT
 24HR VT     30/0600Z 18.5N  55.7W    25 KT
 36HR VT     30/1800Z 20.0N  57.0W    25 KT
 48HR VT     01/0600Z 21.0N  58.2W    25 KT
 72HR VT     02/0600Z 23.0N  60.5W    30 KT
 96HR VT     03/0600Z 24.5N  63.0W    30 KT
120HR VT     04/0600Z 25.5N  65.0W    30 KT
 
$$
FORECASTER MAINELLI
 

WTNT42 KNHC 291440
TCDAT2
TROPICAL DEPRESSION KAREN DISCUSSION NUMBER  19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
1100 AM EDT SAT SEP 29 2007
 
STRONGER THAN AVERAGE SHEAR NEAR KAREN IS WINNING THE BATTLE. 
KAREN IS BECOMING DISORGANIZED AS THE CENTER IS LOSING
DEFINITION AND THE CONVECTION REMAINS WELL REMOVED FROM THE
AREA OF MINIMUM SURFACE PRESSURE. IT LOOKS LIKE KAREN IS
BECOMING A TROUGH OF LOW PRESSURE. I WAS TEMPTED TO MAKE THIS THE
LAST ADVISORY BUT INSTEAD...AND A BETTER OPTION...IS TO DOWNGRADE
KAREN TO A TROPICAL DEPRESSION AND FORECAST IT TO BE A REMNANT LOW
WITHIN THE NEXT 12 HOURS. THIS WILL GIVE SOME TIME TO MONITOR IF A
NEW CENTER REFORMS NEAR THE CONVECTION. THIS IS BASED ON THE FACT
THAT GLOBAL MODELS INSIST ON KEEPING THE CYCLONE. MOREOVER...THE
GFDL AND HWRF MAKE KAREN A HURRICANE BY 3 TO 4 DAYS. THESE MODELS
ASSUME THAT KAREN WILL SURVIVE THE BAND OF STRONG SHEAR FOR ANOTHER
24 HOURS. ALTHOUGH THIS SOLUTION SEEMS UNLIKELY...I HIGHLY
VALUE THE NUMERICAL MODELS...SO KAREN OR ITS REMNANTS WILL CONTINUE
TO BE CLOSELY MONITORED FOR SIGNS OF REGENERATION DURING THE NEXT
FEW DAYS. 

THE DEPRESSION...OR THE BROAD REMNANT CIRCULATION..IS EXPECTED TO
MOVE TOWARD THE NORTHWEST OR 315 DEGREES AT  8 KNOTS FOR THE NEXT
DAY OR SO UNTIL DISSIPATION.  THERE IS NO REASON TO DISCUSS TRACK
GUIDANCE AT THIS TIME WHICH IN FACT HAS NOT CHANGED.

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/1500Z 16.8N  53.8W    30 KT
 12HR VT     30/0000Z 17.5N  55.0W    25 KT...DISSIPATING
 24HR VT     30/1200Z 19.0N  56.0W    20 KT...REMNANT LOW
 36HR VT     01/0000Z 20.5N  57.0W    20 KT...REMNANT LOW
 
$$
FORECASTER AVILA
 

WTNT42 KNHC 292030
TCDAT2
TROPICAL DEPRESSION KAREN DISCUSSION NUMBER  20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL122007
500 PM EDT SAT SEP 29 2007
 
THE SHEAR HAS BEATEN KAREN. SATELLITE IMAGES INDICATE THAT KAREN NO
LONGER HAS A WELL-DEFINED CENTER AND BASICALLY DOES NOT QUALIFY AS A
TROPICAL DEPRESSION. HOWEVER...THERE IS STILL A BROAD AREA OF LOW
PRESSURE WITH STRONG SQUALLS IN A FEW CONVECTIVE BANDS OVER THE
EASTERN HALF OF THE CIRCULATION. THE BROAD AREA OF LOW PRESSURE...
OR THE REMNANTS OF KAREN...ARE EXPECTED TO CONTINUE MOVING TOWARD
THE NORTHWEST OR 315 DEGREES AT 8 KNOTS.
 
AT THIS POINT...I AM NOT GOING TO SPECULATE IF KAREN IS GOING TO
REGENERATE OR NOT. MODELS HAVE THE LUXURY OF GOING BACK AND FORTH
IN STRENGTHENING OR WEAKENING KAREN IN EACH RUN...BUT I DON'T. THE
BEST WE CAN DO IS TO MONITOR THE SYSTEM CLOSELY...AND IF IT COMES
BACK...WHICH IS NOT OUT OF THE QUESTION...REINITIATE ADVISORIES. 
FOR NOW...THIS IS THE LAST ADVISORY ON KAREN. ADDITIONAL
INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS
FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS
HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/2100Z 17.3N  54.3W    30 KT
 12HR VT     30/0600Z 18.0N  55.5W    25 KT...REMNANT LOW
 24HR VT     30/1800Z...DISSIPATED
 
$$
FORECASTER AVILA
 

