Hurricane PATRICIA

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TROPICAL STORM PATRICIA DISCUSSION NUMBER  20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2 AM PDT SAT OCT 25 2003

PATRICIA HAS A VERY POOR SATELLITE APPEARANCE THIS MORNING...AS MOST
OF THE ASSOCIATED CONVECTION HAS DISSIPATED.  EVEN WITH THE HELP OF
RECENT TRMM...SSM/I...AND QUIKSCAT OVERPASSES...THE LOW-LEVEL
CENTER REMAINS VERY HARD TO FIND.  THE INITIAL POSITION IS BASED ON
QUIKSCAT AND EXTRAPOLATION FROM THE PREVIOUS POSITION.  THE TRMM
AND SSM/I...ALONG WITH SAB AND AFWA...SUGGEST THAT A NEW CENTER
COULD BE FORMING ABOUT 120 NM EAST OF THE CURRENT POSITION. 
HOWEVER...SINCE THE CONVECTION IS FADING EVEN THERE THIS APPEARS
RATHER DUBIOUS.  THE INITIAL INTENSITY REMAINS 35 KT BASED ON
SATELLITE INTENSITY ESTIMATES FROM ALL AGENCIES.  THIS MAY BE
GENEROUS...BUT WITH THE POSSIBILITY OF A CONVECTIVE FLARE-UP DURING
THE DIURNAL MAXIMUM THE CYCLONE WILL STAY A TROPICAL STORM FOR ONE
MORE ADVISORY CYCLE.

THE INITIAL MOTION IS A HIGHLY UNCERTAIN 340/4.  WATER VAPOR IMAGERY
INDICATES A MID/UPPER-LEVEL LOW NEAR 25N120W...AND AN UPPER-LEVEL
ANTICYCLONE NEAR 13N96W.  IR SATELLITE IMAGERY AND LARGE-SCALE
MODEL ANALYSES SUGGEST A WEAKNESS IN THE LOW-LEVEL RIDGE NORTH OF
THE CYCLONE.  THIS COMBINATION SHOULD STEER PATRICIA SLOWLY NORTH-
NORTHWESTWARD OR NORTHWARD FOR THE NEXT 48-72.  SEVERAL MODELS
STILL CALL FOR RECURVATURE BEYOND THAT TIME...WHICH NOW APPEARS
VERY UNLIKELY GIVEN THE STATE OF THE STORM.  THE MOST LIKELY
SCENARIO IS FOR PATRICIA TO TURN MORE WESTWARD AS IT WEAKENS...AND
THE CYCLONE MAY VERY WELL DISSIPATE BEFORE THAT CAN OCCUR.  GIVEN
ALL THE UNCERTAINIES... ESPECIALLY IN THE INITIAL LOCATION...THIS
FORECAST TRACK IS AN UPDATE OF THE PREVIOUS SLOW NORTH-
NORTHWESTWARD MOTION.

PATRICIA LOOKS TOO POORLY ORGANIZED TO STRENGTHEN AT THIS TIME...AND
SATELLITE IMAGERY SUGGESTS THAT THE VERTICAL SHEAR IS INCREASING. 
LARGE-SCALE MODELS FORECAST THE CYCLONE TO ENCOUNTER UPPER-LEVEL
WESTERLY TO SOUTHWESTERLY FLOW FOR THE NEXT 5 DAYS...WITH THE SHEAR
GRADUALLY INCREASING THE FARTHER NORTH IT GETS.  THE INTENSITY
FORECAST NOW CALLS FOR NO STRENGTHENING FOR 36 HR AS PATRICIA
ENCOUNTERS LIGHT-MODERATE SHEAR...FOLLWED BY WEAKENING AS IT
ENCOUNTERS STRONGER SHEAR.  PATRICIA COULD WELL DISSIPATE FASTER
THAN CURRENTLY FORECAST.

FORECASTER BEVEN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      25/0900Z 15.1N 113.5W    35 KT
 12HR VT     25/1800Z 15.8N 113.7W    35 KT
 24HR VT     26/0600Z 16.9N 114.0W    35 KT
 36HR VT     26/1800Z 17.6N 114.2W    35 KT
 48HR VT     27/0600Z 18.1N 114.4W    30 KT
 72HR VT     28/0600Z 18.5N 114.5W    25 KT...DISSIPATING
 96HR VT     29/0600Z 20.0N 115.0W    20 KT...REMNANT LOW
120HR VT     30/0600Z...DISSIPATED
 
 
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