Hurricane PATRICIA

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HURRICANE PATRICIA DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
8 AM PDT WED OCT 22 2003
 
THERE IS NOT MUCH THAT HAS CHANGED WITH PATRICIA OVER THE PAST SIX
HOURS.  THE CENTER STILL APPEARS TO BE NEAR THE SOUTHWESTERN EDGE
OF THE OVERCAST.  SATELLITE INTENSITY T/CI NUMBERS ARE 3.5/4.5...
AND SO I WILL KEEP THE INITIAL INTENSITY AT 65 KT UNTIL THE
STRUCTURE CAN BE BETTER DETERMINED FROM VISIBLE IMAGERY OR
ADDITIONAL MICROWAVE PASSES IN A COUPLE OF HOURS.
 
THE INITIAL MOTION IS 285/8.  THERE IS A NARROW MID-LEVEL RIDGE
SEPARATING PATRICIA FROM THE MID- TO UPPER-LEVEL LOW OVER THE
SOUTHERN BAJA PENINSULA.  THERE CONTINUES TO BE A VERY LARGE SPREAD
IN THE TRACK MODEL GUIDANCE...WITH THE AVN KEEPING A WEAK CYCLONE
ON A WEST-NORTHWEST TRACK SOUTH OF THE RIDGE AXIS...WHILE THE UKMET
AND GFDL BRING A STRONGER CYCLONE NORTH-NORTHWESTWARD THROUGH THE
RIDGE OVER THE NEXT 72 HOURS.  THE NOGAPS IS IN BETWEEN.  NEAR THE
END OF THE FORECAST PERIOD...THE GFDL RESPONDS TO STRONG UPPER-
LEVEL WESTERLIES BY RECURVING A MAJOR HURRICANE INTO NORTHWESTERN
MEXICO...WHILE MOST OF THE REST OF THE GUIDANCE WEAKENS THE CYCLONE
AND TAKES IT WESTWARD WITH THE LOW-LEVEL FLOW.  THE PREVIOUS
ADVISORY TRACK TOOK A MIDDLE GROUND BETWEEN THESE OPTIONS AND I
HAVE NO PARTICULAR REASON YET TO CHOOSE ONE OVER THE OTHER.  THE
OFFICIAL FORECAST IS VERY CLOSE TO THE PREVIOUS TRACK.  HOWEVER...
MY SUSPICION IS THAT THE GFDL SCENARIO IN PARTICULAR IS UNLIKELY
GIVEN THE LARGE SHEAR FORECAST BY THE GLOBAL MODELS TO BE PRESENT
NORTH OF ABOUT 17N.
 
FORECASTER FRANKLIN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      22/1500Z 12.3N 106.9W    65 KT
 12HR VT     23/0000Z 12.6N 108.0W    65 KT
 24HR VT     23/1200Z 13.3N 109.0W    65 KT
 36HR VT     24/0000Z 14.1N 110.2W    65 KT
 48HR VT     24/1200Z 15.0N 111.0W    65 KT
 72HR VT     25/1200Z 17.0N 112.0W    55 KT
 96HR VT     26/1200Z 18.5N 112.5W    50 KT
120HR VT     27/1200Z 20.0N 112.5W    40 KT
 
 
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