Hurricane PATRICIA

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HURRICANE PATRICIA DISCUSSION NUMBER   6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
2 PM PDT TUE OCT 21 2003
 
THE LATEST SATELLITE ESTIMATES FROM SAB AND TAFB SUGGEST A MORE
WESTWARD MOTION TO PATRICIA OVER THE PAST 6 HOURS...WITH A MOVEMENT
OF APPROXIMATELY 9 KNOTS.  HOWEVER...BELIEVE THIS IS A TEMPORARY
FLUCTUATION IN THE TRACK...WITH THE LATEST FORECAST TRACK KEEPING A
MOTION OF 305-310 DEGREES FOR THE NEXT 48 HOURS BEFORE TURNING THE
SYSTEM MORE NORTHERLY BEYOND 72 HOURS.  

PATRICIA CONTINUES TO MOVE GENERALLY WEST NORTH WESTWARD ON THE
SOUTHERN SIDE OF THE MID LEVEL ANTICYCLONE OVER WESTERN NOAM.  A
WEAK MID LEVEL LOW CONTINUES TO SPIN ON THE SOUTH SIDE OF THIS UPPER
HIGH NEAR CABO SAN LUCAS WELL TO THE NORTH OF PATRICIA...BUT APPEARS
NOT TO BE INFLUENCING THE SYSTEM TRACK WISE OR INTENSITY WISE AT
THE MOMENT.

THERE CONTINUES TO BE A LARGE SPREAD IN LATEST GUIDANCE, ESPECIALLY
BEYOND 36 HOURS WHEN ONE CLUSTER OF THE OBJECTIVE AIDS CONTINUES TO
SHOW A WEST NORTHWEST TRACK THROUGH THE FIVE DAY FORECAT PERIOD,
WHILE A SECOND SET TAKES PATRICIA ON A MORE NORTHERLY TRACK.  WITH
INDICATIONS IN LATEST GFS AND UKMET THAT THE WESTEN NOAM UPPER
RIDGE WILL WEAKEN DURING THU...BELIEVE THE MODEL CLUSTERS
SUGGESTING A MORE NORTHWARD TRACK ARE REASONABLE.  THIS IS THE
DIRECTION THE OFFICIAL FORECAST FOLLOWED....BEING TO THE LEFT OF
THE PREVIOUS TRACK GIVEN LATEST MOVEMENT.  LATEST TRACK ALSO SLOWED
PREVIOUS TRACK AS PATRICIA MAY MOVE INTO A GENERALLY WEAKER FLOW
REGIME TOWARD THE END OF THE FORECAST PERIOD.  

THE CURRENT INTENSITY REMAINS AT 65 KNOTS BASED ON DVORAK
T-NUMBERS OF 4.0.  THE INTENSITY MODELS SHOW
POTENTIAL FOR STRENGTHENING THROUGH AT LEAST 48 HOURS.  WITH THE
MAIN SHEAR THREAT APPEARING TO BE THE UPPER LOW TO THE NORTH OF THE
SYSTEM...AND THIS SYSTEM EXPECTED TO WEAKEN AND MOVE EASTWARD
THU...BELIEVE PATRICIA MAY NOT ENCOUNTER SIGNIFICANT SHEAR TO
WEAKEN IT.  OFFICIAL FORECAST TRACK STRENGTHENS PATRICIA TO 95 KTS
BY 48 HOURS...WEAKENING IT BEYOND THIS AS THE SYSTEM THEN BEGINS TO
MOVE A  MORE NORTHWARD TRACK.

FORECASTER ORAVEC
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      21/2100Z 11.7N 104.4W    65 KT
 12HR VT     22/0600Z 12.3N 105.5W    75 KT
 24HR VT     22/1800Z 13.1N 106.8W    85 KT
 36HR VT     23/0600Z 14.1N 108.0W    90 KT
 48HR VT     23/1800Z 15.1N 109.2W    95 KT
 72HR VT     24/1800Z 17.1N 109.7W    85 KT
 96HR VT     25/1800Z 18.5N 109.8W    75 KT
120HR VT     26/1800Z 20.0N 109.8W    65 KT
 
 
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