000
WTPZ43 KNHC 220248
TCDEP3
TROPICAL STORM GENEVIEVE DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP082008
800 PM PDT MON JUL 21 2008
 
EASTERLY SHEAR STILL APPEARS TO BE AFFECTING THE VERTICAL STRUCTURE
OF GENEVIEVE WITH A MID-LEVEL CIRCULATION NOTED A LITTLE TO THE
NORTHWEST OF THE ANALYZED SURFACE CENTER. SATELLITE INTENSITY
ESTIMATES FROM TAFB AND SAB REMAIN A CONSENSUS T2.5 SO THE INITIAL
INTENSITY WILL BE KEPT AT 35 KT.

GENEVIEVE HAS BEEN MOVING FAIRLY QUICKLY AT 285/16 FOR THE PAST
12 HOURS OR SO. THE CYCLONE LIES ON THE SOUTHERN PERIPHERY OF A WEAK
MID-LEVEL RIDGE OVER NORTHEASTERN MEXICO...BUT THIS FEATURE IS
EXPECTED TO BUILD FARTHER NORTH ACROSS THE U.S. ROCKIES RESULTING
IN A DECREASE OF THE STEERING FLOW WITHIN THE NEXT 24 HOURS. MOST
OF THE DYNAMICAL GUIDANCE IS FAIRLY TIGHTLY-CLUSTERED THROUGH 5
DAYS...EXCEPT FOR THE GFS AND CANADIAN WHICH SHOW A SOUTHWARD BEND
IN 1-2 DAYS AND THE GFDL WHICH BRINGS GENEVIEVE TO A SLOW CREEP. BY
DISCOUNTING THE SOUTHERN GFS SOLUTION...THE OFFICIAL FORECAST IS
CLOSE TO A SELECTIVE CONSENSUS OF THE REMAINING DYNAMICAL MODELS AND
PERHAPS JUST A LITTLE NORTH OF THE PREVIOUS FORECAST TRACK.

THE STRONG EASTERLY SHEAR OVER GENEVIEVE IS EXPECTED TO WEAKEN BY
12-24 HOURS. ONE WOULD THINK THAT THIS WOULD BE CONDUCIVE FOR
FAIRLY QUICK STRENGTHENING...BUT STRANGELY...ONLY THE SHIPS MODEL IS
VERY AGGRESSIVE IN BRINGING GENEVIEVE TO HURRICANE STRENGTH.
MICROWAVE DATA SHOW SSTS AS COLD AS 23C IN A COLD WAKE GENERATED BY
TROPICAL STORM FAUSTO AHEAD OF GENEVIEVE...AND IT DOES NOT APPEAR
THAT THE WEEKLY REYNOLDS SSTS INGESTED BY THE SHIPS MODEL HAVE
ACCOUNTED FOR THIS FEATURE. FOR THAT REASON THE FORECAST INTENSITY
REMAINS BELOW SHIPS GUIDANCE IN FAVOR OF THE SLOW AND GRADUAL
STRENGTHENING ANTICIPATED BY THE OTHER INTENSITY GUIDANCE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      22/0300Z 14.3N 104.0W    35 KT
 12HR VT     22/1200Z 14.7N 105.7W    40 KT
 24HR VT     23/0000Z 15.1N 107.4W    45 KT
 36HR VT     23/1200Z 15.6N 109.2W    55 KT
 48HR VT     24/0000Z 16.2N 110.7W    60 KT
 72HR VT     25/0000Z 17.0N 113.5W    65 KT
 96HR VT     26/0000Z 17.5N 116.5W    60 KT
120HR VT     27/0000Z 18.0N 120.0W    55 KT
 
$$
FORECASTER BERG/RHOME