991 
 WTNT45 KNHC 282035
 TCDAT5
 TROPICAL STORM DANNY DISCUSSION NUMBER  10
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL052009
 500 PM EDT FRI AUG 28 2009
  
 AFTER STALLING EARLIER THIS AFTERNOON...THE CENTER OF DANNY IS
 FINALLY MOVING SLOWLY NORTHWARD OR NORTH-NORTHEASTWARD. DATA FROM AN
 AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT SUGGEST THAT DANNY IS
 STILL A MINIMAL TROPICAL STORM...BASED ON A 33-KT OBSERVATION FROM
 THE SFMR IN THE SOUTHEASTERN QUADRANT.
  
 THE INTENSITY FORECAST SHOWS THE POSSIBILITY FOR A LITTLE
 STRENGTHENING IN THE SHORT TERM...AS THE INCREASING UPPER-LEVEL
 DIVERGENCE COULD SUPPORT THE REDEVELOPMENT OF CONVECTION NEAR THE
 CENTER. HOWEVER...BY 24 HOURS...DANNY WILL BE MOVING INTO A VERY
 UNFAVORABLE ENVIRONMENT FOR A TROPICAL CYCLONE...WITH THE SHIPS
 MODEL SHOWING WIND SHEAR INCREASING TO 35 KT BY THAT TIME. BY 36
 HOURS...DANNY WILL BE OVER SSTS OF NEAR 20C...AND INTERACTING WITH
 THE DEEP-LAYER BAROCLINIC TROUGH OVER THE EASTERN U.S.  MOST OF
 THE LATEST GLOBAL MODELS AND PHASE SPACE DIAGRAMS SHOW THAT DANNY
 WILL BE EXTRATROPICAL BY THAT TIME. THERE IS THE POTENTIAL FOR SOME
 INTENSIFICATION OF DANNY LATE IN THE FORECAST PERIOD AS AN
 EXTRATROPICAL CYCLONE OVER THE NORTH ATLANTIC.
  
 THE GUIDANCE WAS INITIALIZED WITH A LONG TERM MOTION OF 315/08...
 AND REMAINS IS GOOD AGREEMENT ON THE RAPID ACCELERATION OF DANNY
 NORTHWARD AND NORTH-NORTHEASTWARD. IN FACT...THE MODEL SPREAD IS
 SMALLER NOW THAN IT WAS EARLIER TODAY. THE OFFICIAL TRACK IS SLOWER
 THAN THE MODEL CONSENSUS THROUGH MOST OF THE PERIOD DUE TO THE SLOW
 INITIAL MOTION. FROM 24 TO 36 HOURS...THE NEW FORECAST IS SHIFTED
 TO THE RIGHT OF THE PREVIOUS FORECAST TRACK...BUT DANNY IS STILL
 EXPECTED TO MOVE CLOSE TO THE SOUTHEASTERN COAST OF NEW ENGLAND AND
 APPROACH NOVA SCOTIA IN 36-48 HOURS.
  
 DATA FROM THE AIRCRAFT SUGGEST THAT THE ONLY 34-KT WINDS ARE LOCATED
 IN THE SOUTHEASTERN QUADRANT. THE LACK OF WINDS ON THE WEST SIDE OF
 DANNY LESSEN THE THREAT FOR TROPICAL STORM WIND REACHING THE NORTH
 CAROLINA OUTER BANKS. HOWEVER...THE WATCH IS LEFT IN PLACE IN CASE
 THE WIND FIELD BECOMES BETTER DEFINED ON THE WESTERN SIDE OF DANNY.
 AS DANNY BECOMES EXTRATROPICAL...ITS EXPANDING WIND FIELD MAY
 IMPACT THE COAST OF NEW ENGLAND. THESE POTENTIAL IMPACTS WILL BE
 HANDLED WITH GALE WARNINGS AND OTHER PRODUCTS ISSUED BY LOCAL NWS
 OFFICES IN THAT REGION.
  
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      28/2100Z 30.4N  75.4W    35 KT
  12HR VT     29/0600Z 32.7N  75.8W    40 KT
  24HR VT     29/1800Z 37.3N  73.2W    40 KT
  36HR VT     30/0600Z 41.9N  68.2W    40 KT...EXTRATROPICAL
  48HR VT     30/1800Z 46.5N  61.4W    40 KT...EXTRATROPICAL
  72HR VT     31/1800Z 50.5N  49.5W    40 KT...EXTRATROPICAL
  96HR VT     01/1800Z 53.0N  35.0W    45 KT...EXTRATROPICAL
 120HR VT     02/1800Z 55.0N  22.0W    50 KT...EXTRATROPICAL
  
 $$
 FORECASTER BRENNAN