WTNT45 KNHC 250859
TCDAT5
 
TROPICAL DEPRESSION TEN DISCUSSION NUMBER   1
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102011
500 AM EDT THU AUG 25 2011
 
THE AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE SEVERAL
HUNDRED MILES WEST-SOUTHWEST OF THE SOUTHERN CAPE VERDE ISLANDS HAS
ACQUIRED SUFFICIENT ORGANIZATION TO BE DECLARED A TROPICAL
DEPRESSION.  THE CENTER APPEARS TO BE LOCATED NEAR THE NORTHEAST
TIP OF A CURVED BAND WRAPPING AROUND THE WESTERN SEMICIRCLE.
SATELLITE INTENSITY ESTIMATES ARE AT T2.5 FROM TAFB AND SAB WHICH
SUGGEST THAT THE DEPRESSION COULD BE NEAR TROPICAL STORM STRENGTH.
HOWEVER...GIVEN THE UNCERTAINTY REGARDING THE CENTER LOCATION AND
THE RECENT WARMING OF CONVECTIVE TOPS NEAR THE ESTIMATED CENTER...A
MORE CONSERVATIVE ASSESSMENT OF THE INTENSITY SEEMS MOST PRUDENT.
THE INITIAL INTENSITY IS SET AT 30 KT.
 
SINCE THE CENTER HAS NOT BEEN WELL FORMED...THE INITIAL MOTION
ESTIMATE IS A FAIRLY UNCERTAIN 280/10.  THE DEPRESSION SHOULD
DECELERATE ON A WEST-NORTHWESTWARD AND THEN NORTHWESTWARD COURSE
DURING THE NEXT DAY OR TWO AS IT NEARS THE WESTERN EDGE OF A LOW-
TO MID-LEVEL RIDGE OVER THE FAR EASTERN ATLANTIC.  GLOBAL MODELS
SHOW A WEAKNESS IN THE RIDGE ALONG 35W IN 2-3 DAYS WHICH SHOULD
BECOME MORE PRONOUNCED AS A MID- TO UPPER-LEVEL TROUGH BEGINS TO
DIG SOUTHWARD OVER THE NORTHEAST ATLANTIC.  THIS SHOULD CAUSE THE
TRACK OF THE CYCLONE TO TURN TOWARD THE NORTH-NORTHWEST AND
POSSIBLY THE NORTH LATER IN THE FORECAST PERIOD.  THE TRACK AROUND
96-120 HOURS IS HIGHLY DEPENDENT ON THE VERTICAL INTEGRITY OF THE
CYCLONE...WITH A WEAKER/SHALLOWER SYSTEM LIKELY LYING WEST OF THE
FORECAST TRACK.  THE OFFICIAL NHC TRACK IS CLOSE TO THE MULTI-MODEL
CONSENSUS TVCN.
 
EVEN THOUGH THE DEPRESSION SHOULD TRACK OVER WARM ENOUGH WATERS
DURING THE NEXT COUPLE OF DAYS...ANALYSES FROM UW-CIMSS CURRENTLY
SHOW 15-20 KT OF NORTHEASTERLY SHEAR OVER THE DEPRESSION WHICH
IS FORECAST BY THE SHIPS MODEL TO CONTINUE.  ALTHOUGH A TEMPORARY
REDUCTION OF THE SHEAR COULD OCCUR IN ABOUT 48 HOURS...THE ABRUPT
TURN OF THE CYCLONE TOWARD THE NORTH-NORTHWEST BEYOND THIS TIME WILL
BRING IT OVER 25C-26C WATERS AND LATER IN A REGION OF INCREASING
SOUTHWESTERLY SHEAR ASSOCIATED WITH THE SOUTHWARD EXTENSION OF AN
UPPER-LEVEL TROUGH OVER THE NORTHEAST ATLANTIC. THE OFFICIAL NHC
INTENSITY FORECAST IS IN GOOD AGREEMENT WITH THE MULTI-MODEL
CONSENSUS THROUGH 48 HOURS...SHOWING SLOW STRENGTHENING. WEAKENING
IS INDICATED AFTER THAT TIME IN LIGHT OF THE NEGATIVE ENVIRONMENTAL
FACTORS THE CYCLONE IS FORECAST TO ENCOUNTER AND IS BELOW MOST THE
GUIDANCE. 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  25/0900Z 12.4N  30.4W   30 KT  35 MPH
 12H  25/1800Z 12.8N  31.8W   35 KT  40 MPH
 24H  26/0600Z 13.5N  33.4W   40 KT  45 MPH
 36H  26/1800Z 14.5N  34.3W   45 KT  50 MPH
 48H  27/0600Z 15.5N  35.1W   50 KT  60 MPH
 72H  28/0600Z 17.7N  36.1W   45 KT  50 MPH
 96H  29/0600Z 20.0N  37.0W   35 KT  40 MPH
120H  30/0600Z 22.5N  38.5W   30 KT  35 MPH
 
$$
FORECASTER KIMBERLAIN
 

WTNT45 KNHC 251445
TCDAT5
 
TROPICAL DEPRESSION TEN DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102011
1100 AM EDT THU AUG 25 2011

AFTER BEING CLOSE TO A TROPICAL STORM OVERNIGHT...THE CLOUD PATTERN
OF THE DEPRESSION HAS BECOME LESS ORGANIZED WITH A DECREASE IN
CONVECTION AND CURVED BANDING. ALTHOUGH DVORAK ESTIMATES REMAIN AT
STORM STRENGTH...AN ASCAT PASS AT 1126 UTC SUGGESTED MAXIMUM WINDS
OF 25 TO 30 KT...WHICH WAS LESS THAN WHAT WAS MEASURED ON THE LAST
PASS.  THE INITIAL WIND SPEED WILL STAY AT 30 KT FOR THIS ADVISORY.

THE ASCAT DATA SHOWED THAT THE CIRCULATION OF THE DEPRESSION IS
ELONGATED FROM NORTHEAST TO SOUTHWEST...WHICH IS NOT EXACTLY A
FAVORABLE STRUCTURE FOR MUCH NEAR-TERM INTENSIFICATION.  IN
ADDITION...NORTHEASTERLY SHEAR IS FORECAST TO REMAIN MODERATE TO
STRONG TODAY.  THUS THE NHC FORECAST IS REDUCED FROM THE PREVIOUS
ONE IN THE SHORT-TERM.  SOME INTENSIFICATION SEEMS LIKELY ON FRIDAY
WITH LESS SHEAR WHILE THE CYCLONE REMAINS OVER WARM WATERS. 
HOWEVER...THERE IS A BIG SPLIT BETWEEN THE DYNAMICAL AND
STATISTICAL GUIDANCE...WITH THE GFDL/HWRF MODELS SHOWING LITTLE
STRENGTHENING FOR THE NEXT SEVERAL DAYS WHILE THE SHIPS/LGEM MODELS
FORECAST THE DEPRESSION TO BECOME HURRICANE.  WITH SUCH A LARGE
SPREAD IN THE GUIDANCE...NO CHANGE IS MADE TO THE PREVIOUS FORECAST
BEYOND FRIDAY.  WEAKENING SHOULD COMMENCE BY DAY THREE DUE TO AN
INCREASE IN SHEAR AND DECREASE IN SSTS.   

AN UNCERTAIN ESTIMATE OF INITIAL MOTION IS 290/10.  A MID-LEVEL
RIDGE TO THE NORTH OF THE DEPRESSION SHOULD BREAK DOWN AS A TROUGH
FORMS OVER THE EASTERN ATLANTIC OCEAN.  THIS SHOULD CAUSE THE
CYCLONE TO TURN TOWARD THE NORTHWEST AND NORTH-NORTHWEST DURING THE
NEXT FEW DAYS.  ALTHOUGH THE GUIDANCE HAS THIS GENERAL IDEA...THERE
ARE A VARIETY OF SOLUTIONS ON HOW QUICKLY THE MORE NORTHWARD MOTION
STARTS.  PART OF THE PROBLEM IS THAT THE TRACK FORECAST IS RATHER
DEPENDENT ON THE INTENSITY FORECAST WITH A DEEPER SYSTEM MORE
LIKELY TO BE PULLED MORE TO THE NORTH THAN A WEAKER ONE.  THE NHC
FORECAST WILL SHOW A NORTH-NORTHWEST MOTION BY DAY 3 AND ASSUMES
THE CYCLONE GAINS SOME STRENGTH.  THE NEW FORECAST IS TO THE RIGHT
OF THE PREVIOUS ONE DURING THE DAY OR SO...CLOSE TO A BLEND OF THE
ECMWF MODEL AND THE HURRICANE FORECAST IMPROVEMENT PROGRAM
EXPERIMENTAL CONSENSUS.  MOST OF THE MODELS SHOW A SHARPER LEFT
TURN IN THE LONGER-RANGE PERIOD...SO THE TRACK AT THAT TIME IS WEST
OF THE PREVIOUS FORECAST.
  
FORECAST POSITIONS AND MAX WINDS
 
INIT  25/1500Z 13.3N  31.8W   30 KT  35 MPH
 12H  26/0000Z 13.9N  32.9W   30 KT  35 MPH
 24H  26/1200Z 14.7N  34.1W   35 KT  40 MPH
 36H  27/0000Z 15.6N  35.2W   45 KT  50 MPH
 48H  27/1200Z 16.6N  35.9W   50 KT  60 MPH
 72H  28/1200Z 18.7N  37.0W   45 KT  50 MPH
 96H  29/1200Z 20.5N  38.0W   35 KT  40 MPH
120H  30/1200Z 22.0N  40.5W   30 KT  35 MPH
 
$$
FORECASTER BLAKE
 

WTNT45 KNHC 252059
TCDAT5
 
TROPICAL DEPRESSION TEN DISCUSSION NUMBER   3
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102011
500 PM EDT THU AUG 25 2011
 
DEEP CONVECTION HAS REDEVELOPED IN THE WESTERN SEMICIRCLE OF THE
CYCLONE...ALTHOUGH THE CIRCULATION REMAINS ELONGATED.  THE CURVED
BANDS FROM EARLIER TODAY ALSO APPEAR TO HAVE MORPHED INTO A
BURSTING PATTERN...INDICATIVE OF A SHEARED CYCLONE.  THE INITIAL
WINDS WILL REMAIN 30 KT FOR THIS ADVISORY.  NORTHEASTERLY SHEAR
COULD PREVENT STRENGTHENING OF THE DEPRESSION IN THE SHORT-TERM
ALONG WITH THE POOR INITIAL STRUCTURE.  THE BEST CHANCE FOR THIS
SYSTEM TO INTENSIFY IS ON FRIDAY WITH GLOBAL MODELS FORECASTING A
DECREASE IN SHEAR WHILE THE SYSTEM REMAINS OVER WARM WATER. 
HOWEVER...THE FAVORABLE ENVIRONMENTAL CONDITIONS SHOULD BE
SHORT-LIVED AS SHEAR IS FORECAST TO INCREASE MARKEDLY AFTER 48
HOURS IN ADDITION TO THE DEPRESSION ENCOUNTERING COOLER WATERS. 
THE NHC INTENSITY PREDICTION IS REDUCED SLIGHTLY FROM THE PREVIOUS
ONE AND IS CLOSE TO THE MULTI-MODEL CONSENSUS.

THE DEPRESSION APPEARS TO HAVE SLOWED AND TURNED TO THE RIGHT...
WITH AN INITIAL MOTION OF 300/8.  THIS TURN IS DUE TO A MID-LEVEL
RIDGE WEAKENING AS A TROUGH FORMS OVER THE EASTERN ATLANTIC OCEAN. 
THE CYCLONE SHOULD MOVE TOWARD THE NORTHWEST AND NORTH-NORTHWEST
DURING THE NEXT FEW DAYS INTO THIS WEAKNESS.  A LEFTWARD TURN IS
ANTICIPATED AFTER 3 DAYS AS THE CYCLONE DECAYS AND BECOMES MORE
STEERED BY THE LOW-LEVEL RIDGE.  THE MODELS CONTINUE TO HAVE A
LARGE SPREAD BY THE END OF THE FORECAST PERIOD...WHICH SEEMS TO BE
LINKED TO THE DEPTH OF THE TROUGH.  SINCE THE DEPRESSION IS NOT
EXPECTED TO GAIN MUCH STRENGTH...THE FORECAST LIES NEAR OR LEFT OF
THE MODEL CONSENSUS...AND IS SHIFTED WESTWARD FROM THE PREVIOUS ONE
IN THE LONG RANGE. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  25/2100Z 13.8N  32.4W   30 KT  35 MPH
 12H  26/0600Z 14.4N  33.3W   30 KT  35 MPH
 24H  26/1800Z 15.2N  34.4W   35 KT  40 MPH
 36H  27/0600Z 16.0N  35.3W   40 KT  45 MPH
 48H  27/1800Z 16.9N  36.0W   45 KT  50 MPH
 72H  28/1800Z 19.0N  37.5W   40 KT  45 MPH
 96H  29/1800Z 20.5N  39.5W   30 KT  35 MPH
120H  30/1800Z 21.5N  42.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER BLAKE
 

WTNT45 KNHC 260241
TCDAT5
 
TROPICAL DEPRESSION TEN DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102011
1100 PM EDT THU AUG 25 2011
 
DESPITE THE PERSISTENCE OF A LARGE AREA OF DEEP CONVECTION...THE
LOW-LEVEL CENTER STILL APPEARS TO BE DISPLACED ABOUT A DEGREE TO
THE EAST OF THE EDGE OF THE COLDER CLOUD TOPS.  THIS STRUCTURE IS
CONSISTENT WITH THE NORTHEASTERLY SHEAR OF ABOUT 20 KT SHOWN OVER
THE DEPRESSION BY THE SHIPS MODEL AND THE UW-CIMSS SATELLITE
ANALYSES.  GIVEN THE RELATIVELY DISORGANIZED STRUCTURE OF THE
CYCLONE...THE INITIAL INTENSITY IS HELD AT 30 KT FOR THIS ADVISORY
IN AGREEMENT WITH A BLEND OF DVORAK FINAL-T AND CI NUMBERS FROM
TAFB AND SAB.  THE ENVIRONMENTAL CONDITIONS NEVER BECOME ESPECIALLY
CONDUCIVE FOR MUCH INTENSIFICATION...HOWEVER THERE IS A SMALL
WINDOW OF OPPORTUNITY FOR GRADUAL STRENGTHENING AS THE SHEAR
DECREASES OVER THE NEXT DAY OR TWO.  BY 48 HOURS THE CYCLONE WILL
BE MOVING OVER WATERS NEAR OR BELOW 26C...WHICH SHOULD HALT ANY
INTENSIFICATION.  WESTERLY SHEAR IS EXPECTED TO INCREASE BY 72
HOURS...AND SHOULD LEAD TO STEADY WEAKENING TO A REMNANT LOW BY THE
END OF THE PERIOD.  THE NHC INTENSITY FORECAST IS UNCHANGED FROM
THE PREVIOUS ADVISORY AND IS CLOSE TO A BLEND OF THE SHIPS AND LGEM
THROUGH 48 HOURS AND LIES BELOW THE INTENSITY CONSENSUS LATE IN THE
PERIOD.  

GIVEN THE DIFFICULTY IN LOCATING THE CENTER...THE INITIAL MOTION
ESTIMATE IS A RATHER UNCERTAIN 295/8.  THE DEPRESSION IS STILL
MOVING GENERALLY TOWARD THE WEST-NORTHWEST TO THE SOUTH OF A
WEAKENING MID-LEVEL RIDGE.  AS THE RIDGE WEAKENS AND A MID- TO
UPPER-LEVEL TROUGH AMPLIFIES NORTH OF THE CYCLONE...A TURN TOWARD
THE NORTHWEST IS EXPECTED FROM 24 TO 72 HOURS.  BEYOND THAT
TIME...THE CYCLONE SHOULD TURN BACK TOWARD THE WEST-NORTHWEST AS
THE TROUGH LIFTS OUT AND THE WEAKENING CYCLONE COMES UNDER THE
INFLUENCE OF THE LOW-LEVEL SUBTROPICAL RIDGE.  THE NEW NHC TRACK
FORECAST IS CLOSE TO THE PREVIOUS ONE AND THE TVCA MULTI-MODEL
CONSENSUS THROUGH 96 HOURS...AND IS SLOWER THAN MOST OF THE
GUIDANCE AT DAY 5. 
 

FORECAST POSITIONS AND MAX WINDS
 
INIT  26/0300Z 14.1N  33.1W   30 KT  35 MPH
 12H  26/1200Z 14.7N  34.0W   30 KT  35 MPH
 24H  27/0000Z 15.5N  34.9W   35 KT  40 MPH
 36H  27/1200Z 16.4N  35.7W   40 KT  45 MPH
 48H  28/0000Z 17.4N  36.4W   45 KT  50 MPH
 72H  29/0000Z 19.5N  38.0W   40 KT  45 MPH
 96H  30/0000Z 20.5N  40.5W   30 KT  35 MPH
120H  31/0000Z 21.5N  43.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER BRENNAN
 

WTNT45 KNHC 260839
TCDAT5
 
TROPICAL DEPRESSION TEN DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102011
500 AM EDT FRI AUG 26 2011
 
RECENT IR IMAGERY AND AN 0350 UTC AMSR-E PASS SUGGEST THAT THE
DEPRESSION IS NOT WELL ORGANIZED...AND THAT THE CIRCULATION IS
SOMEWHAT ELONGATED TO THE EAST OF THE DEEP CONVECTION. THIS APPEARS
TO BE DUE TO CONTINUED NORTHEASTERLY SHEAR OF 15 TO 20 KNOTS AS
ANALYZED BY UW-CIMMS AND THE GFS FIELDS IN THE SHIPS MODEL OUTPUT.
DVORAK T-NUMBERS FROM TAFB AND SAB SUPPORT HOLDING THE INTENSITY AT
30 KT FOR THIS ADVISORY. GIVEN THE CURRENT STRUCTURE OF THE CYCLONE
AND THE FACT THAT MOST OF THE DYNAMICAL MODELS INCLUDING THE GFDL
AND HWRF SHOW LITTLE INTENSIFICATION...THE OFFICIAL INTENSITY
FORECAST HAS BEEN ADJUSTED DOWNWARD AND SHOWS ONLY A BROAD PEAK AT
MINIMAL TROPICAL STORM INTENSITY. BEYOND 48 HOURS...INCREASING
SHEAR SHOULD RESULT IN WEAKENING TO A REMNANT LOW BY DAY 4 WITH THE
CYCLONE DISSIPATING BY DAY 5. IS IS ALSO POSSIBLE THAT VISIBLE
IMAGERY WILL REVEAL THAT THE CENTER IS NO LONGER WELL DEFINED...AND
IF SO THE CYCLONE COULD DEGENERATE TO A REMNANT LOW LATER TODAY.
 
SINCE A CENTER IS DIFFICULT TO IDENTIFY...UNCERTAINTY IN THE INITIAL
POSITION REMAINS HIGH. BASED ON SATELLITE FIXES AND CONTINUITY...THE
INITIAL MOTION ESTIMATE REMAINS 295/8. WHILE OVERALL THE SYNOPTIC
REASONING REMAINS UNCHANGED...A TREND TOWARD A WEAKER CYCLONE
SUGGESTS THAT LESS OF A POLEWARD TURN INTO THE MID-LEVEL WEAKNESS
WILL OCCUR DURING THE FIRST 2 OR 3 DAYS OF THE PERIOD. THE NHC
FORECAST HAS BEEN ADJUSTED A LITTLE TO THE LEFT OF THE PREVIOUS ONE
TOWARD THE TVCA MULTI-MODEL CONSENSUS THROUGH 72 HOURS AND THE
SHALLOW BAM AT DAY 4.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  26/0900Z 14.5N  33.7W   30 KT  35 MPH
 12H  26/1800Z 15.1N  34.5W   30 KT  35 MPH
 24H  27/0600Z 15.9N  35.5W   35 KT  40 MPH
 36H  27/1800Z 16.8N  36.4W   35 KT  40 MPH
 48H  28/0600Z 17.8N  37.2W   35 KT  40 MPH
 72H  29/0600Z 19.5N  39.0W   30 KT  35 MPH
 96H  30/0600Z 21.0N  41.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  31/0600Z...DISSIPATED
 
$$
FORECASTER BRENNAN
 

WTNT45 KNHC 261437
TCDAT5
 
TROPICAL DEPRESSION TEN DISCUSSION NUMBER   6
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102011
1100 AM EDT FRI AUG 26 2011
 
A DECREASING BURST OF CONVECTION REMAINS ON THE WESTERN SIDE OF THE
DEPRESSION...THOUGH THE CIRCULATION CONTINUES TO BE RATHER
ELONGATED FROM NORTHEAST TO SOUTHWEST. THE DILEMMA WITH THIS SYSTEM
IS THAT WHILE THE CENTER IS STRETCHING THE DEFINITION OF A TROPICAL
CYCLONE...EARLIER ASCAT DATA SUGGESTED THE CYCLONE WAS NEAR STORM
FORCE. GIVEN THE POOR STRUCTURE OF THE SYSTEM...SATELLITE
CLASSIFICATIONS OF 30 KT FROM BOTH TAFB AND SAB...AND THE DECLINING
CONVECTION...IT IS PROBABLY BEST TO LEAVE IT AS A DEPRESSION AT
THIS TIME. IT WOULD NOT BE SURPRISING...HOWEVER...IF THE CYCLONE
WAS A LITTLE STRONGER EARLIER TODAY.

WHILE ANALYSES FROM SHIPS AND UW-CIMSS SUGGEST THE SHEAR IS LOWER
THAN YESTERDAY...THE DEPRESSION HAS NOT BECOME ANY BETTER
ORGANIZED...PROBABLY DUE TO POOR LOW-LEVEL STRUCTURE.  AT THIS
POINT...GIVEN THAT NONE OF THE GLOBAL OR DYNAMICAL MODELS
STRENGTHEN THIS SYSTEM...THE NHC FORECAST WILL SHOW LITTLE CHANGE
IN INTENSITY UNTIL THE CYCLONE DECAYS OVER COOLER WATERS IN A FEW
DAYS.  ANOTHER POSSIBILITY IS THAT THE DEPRESSION COULD DEGENERATE
INTO A TROUGH LATER TODAY...AS IT WOULD NOT TAKE MUCH OF A
DEGRADATION IN STRUCTURE FOR THAT TO OCCUR.

THE INITIAL MOTION IS AN UNCERTAIN 305/7. A MID-TROPOSPHERIC TROUGH
SHOULD CONTINUE TO STEER THE DEPRESSION GENERALLY TOWARD THE
NORTHWEST. HOWEVER...WITH THE SYSTEM NOW EXPECTED TO BE WEAKER...
LESS OF A NORTHWARD TURN IS FORECAST BY MOST OF THE MODELS. THE NHC
FORECAST IS BASICALLY AN UPDATE OF THE PREVIOUS ONE THROUGH 48
HOURS...AND IS SHIFTED LEFTWARD AFTER THAT TIME. THE FORECAST IS
WEST OF THE MODEL CONSENSUS...AND IS CLOSE TO A BLEND OF THE GFS
AND ECMWF MODELS. 

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  26/1500Z 14.9N  34.2W   30 KT  35 MPH
 12H  27/0000Z 15.5N  34.9W   30 KT  35 MPH
 24H  27/1200Z 16.4N  35.8W   30 KT  35 MPH
 36H  28/0000Z 17.4N  36.7W   30 KT  35 MPH
 48H  28/1200Z 18.3N  37.9W   30 KT  35 MPH
 72H  29/1200Z 19.5N  40.0W   25 KT  30 MPH
 96H  30/1200Z 21.0N  42.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  31/1200Z...DISSIPATED
 
$$
FORECASTER BLAKE
 

WTNT45 KNHC 262031
TCDAT5
 
TROPICAL DEPRESSION TEN DISCUSSION NUMBER   7
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102011
500 PM AST FRI AUG 26 2011
 
THE DEPRESSION IS BARELY HOLDING ON TO TROPICAL CYCLONE STATUS.  THE
CIRCULATION OF THE CYCLONE IS QUITE ELONGATED...WITH SEVERAL
SMALLER SWIRLS WITHIN THE CIRCULATION ENVELOPE.  CONVECTION HAS
DIMINISHED AS WELL AND LIES FAR TO THE WEST OF THE CENTER.  THE
INITIAL WINDS ARE KEPT AT 30 KT BASED ON CI NUMBERS FROM
TAFB/SAB...BUT MIGHT BE A LITTLE GENEROUS.  

THE CENTER HAS BEEN SHIFTED A LITTLE BIT TO THE NORTHEAST BASED ON
VISIBLE IMAGES...GIVING A LONGER-TERM MOTION OF ABOUT 315/6.  THIS
GENERAL TRACK AND SPEED IS EXPECTED FOR THE NEXT COUPLE OF DAYS AS
THE DEPRESSION MOVES INTO A WEAKNESS IN THE SUBTROPICAL RIDGE.  A
LEFTWARD TURN IS ANTICIPATED AFTER THE CYCLONE BECOMES A SHALLOW
SYSTEM.  THE NHC FORECAST IS SHIFTED TO THE EAST...MOSTLY BECAUSE
OF THE CENTER RELOCATION...BUT REMAINS WEST OF THE MODEL CONSENSUS.

GIVEN THE SPRAWLING NATURE OF THIS CIRCULATION...ALONG WITH COOLER
SSTS AND INCREASING VERTICAL WIND SHEAR...NO SIGNIFICANT
INTENSIFICATION IS EXPECTED DURING THE NEXT DAY OR SO.  THE CYCLONE
SHOULD WEAKEN OVER THE WEEKEND DUE TO ENVIRONMENTAL CONDITIONS
BECOMING MORE HOSTILE.  THE NHC FORECAST IS LOWERED FROM THE
PREVIOUS ONE...AND IS IN GOOD AGREEMENT WITH GLOBAL AND DYNAMICAL
MODEL FORECAST.  THE DEPRESSION SHOULD BECOME A REMNANT LOW WITHIN
A FEW DAYS...AND IT WOULD NOT BE SURPRISING AT ALL IF IT
DEGENERATED INTO A TROUGH EVEN SOONER THAN THAT.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  26/2100Z 15.6N  34.3W   30 KT  35 MPH
 12H  27/0600Z 16.3N  34.8W   30 KT  35 MPH
 24H  27/1800Z 17.2N  35.7W   30 KT  35 MPH
 36H  28/0600Z 18.1N  36.7W   25 KT  30 MPH
 48H  28/1800Z 18.8N  37.8W   25 KT  30 MPH
 72H  29/1800Z 20.0N  40.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  30/1800Z...DISSIPATED
 
$$
FORECASTER BLAKE
 

