Tropical Storm PATRICIA

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TROPICAL STORM PATRICIA DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
8 PM PDT MON OCT 20 2003

PATRICIA CONTINUES TO BECOME BETTER ORGANIZED AS EVIDENCED BY
INCREASING CURVATURE OF THE CONVECTIVE BANDS AROUND THE CENTER. 
UPPER-LEVEL OUTFLOW APPEARS TO BE GOOD IN ALL QUADRANTS.  CURRENT
INTENSITY IS SET AT 45 KT IN ACCORDANCE WITH DVORAK T-NUMBERS OF
3.0 FROM TAFB AND SAB.  CONTINUED STRENGTHENING IS FORECAST...CLOSE
TO THAT SHOWN BY THE SHIPS GUIDANCE THROUGH 48-72 HOURS.  BEYOND
THAT TIME FRAME...THE GFS SHOWS A SUBSTANTIAL INCREASE IN SHEAR AS
A RESULT OF STRONG 200 MB WESTERLIES NEAR THE PROJECTED TRACK.  THE
OFFICIAL FORECAST DOES NOT SHOW AS MUCH WEAKENING AS SHIPS...WHICH
USES THE SHEAR FORECAST BY THE GFS.  THIS IS OUT OF RESPECT FOR THE
LATEST GFDL MODEL RUN WHICH SHOWS A STRONG HURRICANE IN 4-5 DAYS. 
OBVIOUSLY THERE IS A LOT OF UNCERTAINTY IN THE INTENSITY FORECAST
LATE IN THE PERIOD.

ESTIMATED INITIAL MOTION IS 285/8...AS PATRICIA IS CURRENTLY BEING
STEERED BY MID-LEVEL EASTERLIES.  THERE IS A MID-TROPOSPHERIC LOW
CENTERED NEAR CABO SAN LUCAS...AND THE GLOBAL MODELS PREDICT THAT
THIS SYSTEM WILL SHIFT SLOWLY EASTWARD AND ELONGATE ALONG AN
EAST-WEST AXIS.  THIS FEATURE IS EXPECTED TO CAUSE THE TRACK OF
PATRICIA TO BEND TOWARD THE RIGHT OVER THE NEXT SEVERAL DAYS. 
THERE HAS BEEN A MAJOR CHANGE IN THE GFDL GUIDANCE WITH THAT MODEL
NOW SHOWING A NORTH-NORTHEASTWARD ACCELERATION IN THE LATTER PART
OF THE PERIOD.  THE GFS AND NOGAPS SIMULATIONS SHOW A VERY WEAK
SYSTEM THROUGHOUT THE FORECAST...AND IN FACT THE NOGAPS DOES NOT
REALLY EVEN INITIALIZE THE TROPICAL CYCLONE.  THEREFORE LITTLE
WEIGHT CAN BE PLACED ON THOSE TWO MODELS FOR THIS PACKAGE. THE
OFFICIAL FORECAST TRACK AT 72-96 HOURS IS SHIFTED A LITTLE TO THE
EAST OF THE PREVIOUS ONE...BUT IS NOT NEARLY AS FAR TO THE
NORTHEAST AS THE GFDL TRACK.

FORECASTER PASCH 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      21/0300Z 10.6N 102.3W    45 KT
 12HR VT     21/1200Z 11.1N 103.5W    50 KT
 24HR VT     22/0000Z 11.9N 105.2W    55 KT
 36HR VT     22/1200Z 12.7N 106.6W    65 KT
 48HR VT     23/0000Z 13.6N 107.7W    65 KT
 72HR VT     24/0000Z 15.5N 109.0W    65 KT
 96HR VT     25/0000Z 17.5N 109.5W    60 KT
120HR VT     26/0000Z 20.0N 109.0W    55 KT
 
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