000
WTNT45 KNHC 050859
TCDAT5
TROPICAL STORM JOSEPHINE DISCUSSION NUMBER  13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL102008
500 AM EDT FRI SEP 05 2008
 
CONVENTIONAL SATELLITE IMAGERY DEPICTS AN INCREASE IN DEEP
CONVECTION THIS MORNING...ALTHOUGH STILL DISPLACED TO THE NORTH OF
THE SURFACE CIRCULATION DUE TO STRONG SOUTHERLY SHEAR.  THE INITIAL
INTENSITY IS INCREASED SLIGHTLY TO 45 KT AND IS DERIVED FROM A
BLEND OF THE DVORAK INTENSITY ESTIMATES BASED ON THE SHEAR PATTERN. 
THE CYCLONE IS EXPECTED TO REMAIN WITHIN THE STRONG SOUTHERLY SHEAR
ENVIRONMENT DURING THE NEXT COUPLE OF DAYS PRODUCED BY AN UPPER
LEVEL LOW MOVING IN TANDEM TO THE WEST.  CONSEQUENTLY...GRADUAL
WEAKENING IS REFLECTED IN THE FORECAST THROUGH DAY 3. 
AFTERWARD...THE INTENSITY MODELS ARE SUGGESTING THAT THE TROUGH
WILL FILL ENOUGH TO LESSEN THE SHEAR CAUSING JOSEPHINE TO
STRENGTHEN A BIT.  IN FACT...THE UKMET ACTUALLY INDICATES AN
ANTICYCLONE DEVELOPING NEAR THE SYSTEM AROUND DAY 5 JUST NORTHEAST
OF THE LEEWARD ISLANDS.  THE INTENSITY FORECAST IS BASED ON THE
AFOREMENTIONED SCENARIO AND IS IN BEST AGREEMENT WITH THE INTENSITY
CONSENSUS MODEL.   
 
JOSEPHINE IS MOVING WITHIN THE EAST-SOUTHEASTERLY FLOW OF A WEAKENED
MID-LEVEL RIDGE SITUATED TO THE NORTH.  A 0422Z AMSR-E MICROWAVE
OVERPASS INDICATES THE CYCLONE HAS BEEN MOVING A LITTLE MORE TOWARD
THE NORTHWEST DURING THE PAST 6 HOURS...WITH THE INITIAL MOTION NOW
ESTIMATED AT 305/8.  THE GLOBAL MODELS SUGGEST THAT THE RIDGE WILL
BREAK DOWN FURTHER DURING WITHIN THE 24 TO 36 HOUR PERIOD IN
RESPONSE TO AN APPROACHING MAJOR SHORTWAVE TROUGH FROM THE
NORTH-CENTRAL ATLANTIC.  THE HWRF ACTUALLY SHOWS A SIGNIFICANT
WEAKNESS DEVELOPING AND TURNS JOSEPHINE MORE TOWARD THE
NORTH-NORTHWEST. TOWARD THE END OF THE PERIOD...THE LARGE-SCALE
MODELS ARE INDICATING A REESTABLISHMENT OF THE EASTERN EXTENT OF
THE RIDGE WHICH MAY TURN JOSEPHINE BACK TOWARD THE WEST-NORTHWEST.
THE NHC FORECAST FOLLOWS CLOSELY TO THE MODEL CONSENSUS AND IS
SHIFTED A BIT TO THE RIGHT OF THE PREVIOUS FORECAST.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/0900Z 15.7N  34.3W    45 KT
 12HR VT     05/1800Z 16.1N  35.2W    45 KT
 24HR VT     06/0600Z 16.8N  36.6W    45 KT
 36HR VT     06/1800Z 17.8N  38.5W    40 KT
 48HR VT     07/0600Z 19.0N  40.6W    40 KT
 72HR VT     08/0600Z 21.5N  44.5W    40 KT
 96HR VT     09/0600Z 23.5N  47.5W    40 KT
120HR VT     10/0600Z 25.5N  50.5W    45 KT
 
$$
FORECASTER ROBERTS/KNABB