000
WTNT44 KNHC 271438
TCDAT4
 
TROPICAL DEPRESSION DEBBY DISCUSSION NUMBER  17
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL042012
1100 AM EDT WED JUN 27 2012
 
DEBBY IS STRUGGLING TO SURVIVE AS A TROPICAL CYCLONE. OCCASIONAL
BURSTS OF CONVECTION CONTINUE TO FORM NEAR THE CENTER...BUT ARE
IMMEDIATELY BEING PUSHED TO THE EAST BY STRONG WESTERLY SHEAR. IN
FACT...AT 12Z...THE CONVECTION WAS TOO DISORGANIZED TO WARRANT A
DVORAK CLASSIFICATION. THE LOW-LEVEL CENTER HAS BECOME INCREASINGLY
DISTORTED...WITH AN ELONGATED NORTHEAST-TO-SOUTHWEST APPEARANCE. A
LOW-LEVEL BAROCLINIC ZONE IS ALSO IMPINGING ON THE CYCLONE BUT HAS
NOT YET BECOME INVOLVED WITH THE CIRCULATION CENTER. BUOY REPORTS
NEAR THE CENTER SHOW 1-MINUTE WINDS OF AROUND 25 KT. IT IS ASSUMED
THAT STRONGER WINDS ARE OCCURING IN THE CONVECTION TO THE EAST...SO
THE INITIAL INTENSITY IS KEPT AT 30 KT.

SATELLITE...RADAR...AND SYNOPTIC DATA INDICATE THAT THE CENTER OF
DEBBY MOVED INTO THE WESTERN ATLANTIC AROUND 8Z. USING THESE DATA
SOURCES...THE INITIAL MOTION ESTIMATE IS 085/09. ALTHOUGH A DEEP
TROUGH OVER THE WESTERN ATLANTIC WILL BE IN THE PROCESS OF LIFTING
OUT OVER THE NEXT COUPLE OF DAYS...GLOBAL MODELS SHOW IT HAVING
SUFFICIENT AMPLITUDE TO DRAW DEBBY EAST-NORTHEASTWARD. HAVING
GAINED ENOUGH LATITUDE...STRONGER MID-LATITUDE WESTERLY FLOW SHOULD
THEN CAUSE DEBBY TO ACCELERATE NORTHEASTWARD FOR THE REMAINDER OF
THE FORECAST PERIOD. THE ECMWF/GFS/UKMET ARE IN GOOD AGREEMENT ON
THIS SCENARIO...BUT THE REGIONAL DYNAMICAL MODELS SHOW DEBBY BEING
LEFT BEHIND BY THE WESTERN ATLANTIC TROUGH. ASSUMING THAT DEBBY
REMAINS A DISTINCT ENTITY...THE FORMER CAMP OF MODELS FAVORS THIS
SCENARIO AND SO DOES THIS OFFICIAL FORECAST.

ALTHOUGH THERE SHOULD BE A RELATIVE DECREASE IN THE SHEAR OVER THE
CYCLONE AFTER 24 HOURS...DEBBY WILL REMAIN SURROUNDED BY A LARGE
POOL OF VERY DRY AND STABLE AIR OVER THE WESTERN ATLANTIC EVEN
AFTER THE FRONTAL BOUNDARY RETREATS. THESE FACTORS SHOULD TEMPER
ANY SIGNIFICANT RE-INTENSIFICATION. THE SHIPS/LGEM GENERALLY AGREE
WITH THIS IDEA...NO LONGER SHOWING MUCH STRENGTHENING. IT SHOULD BE
NOTED THAT THE GFS SHOWS DEBBY LOSING ORGANIZATION DURING THE NEXT
48 HOURS AND BECOMING AN OPEN WAVE OVER THE CENTRAL ATLANTIC. IN
THE FACE OF THESE NEGATIVE ENVIRONMENTAL FACTORS...THERE IS A
POSSIBILITY THAT DEBBY WILL DISSIPATE SOON.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  27/1500Z 29.7N  79.8W   30 KT  35 MPH
 12H  28/0000Z 30.1N  77.5W   30 KT  35 MPH
 24H  28/1200Z 30.5N  74.8W   30 KT  35 MPH
 36H  29/0000Z 31.3N  71.8W   30 KT  35 MPH
 48H  29/1200Z 32.3N  69.5W   30 KT  35 MPH
 72H  30/1200Z 35.5N  65.3W   30 KT  35 MPH
 96H  01/1200Z 40.0N  60.0W   35 KT  40 MPH
120H  02/1200Z 46.0N  48.0W   35 KT  40 MPH
 
$$
FORECASTER KIMBERLAIN