Tropical Storm PATRICIA

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TROPICAL STORM PATRICIA DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP192009
200 AM PDT MON OCT 12 2009
 
THE CENTER OF PATRICIA HAS BEEN DIFFICULT TO LOCATE IN INFRARED
SATELLITE IMAGERY THIS MORNING AND THERE HAVE BEEN NO RECENT
MICROWAVE OVERPASSES TO ASSIST.  BASED ON EARLIER ESTIMATES...THE
CENTER APPEARS TO BE NEAR THE NORTHEASTERN EDGE OF THE DEEP
CONVECTION.  THE LATEST DVORAK CLASSIFICATIONS FROM TAFB AND
SAB ARE T3.0 AND T2.5 RESPECTIVELY...WHICH SUPPORTS INCREASING
THE INITIAL INTENSITY TO 40 KT. 

THE INITIAL MOTION ESTIMATE IS 345/6.  PATRICIA IS CURRENTLY MOVING
NORTH-NORTHWESTWARD AROUND THE WESTERN PERIPHERY OF A DEEP-LAYER
RIDGE TO ITS EAST AND A MID- TO UPPER-LEVEL TROUGH TO ITS NORTHWEST.
THE CYCLONE IS EXPECTED TO CONTINUE ON A NORTH-NORTHWESTWARD TO
NORTHWARD MOTION DURING THE NEXT COUPLE OF DAYS.  THEREAFTER...THE
TROUGH IS FORECAST TO LIFT OUT WITH A RIDGE BUILDING TO THE NORTH
OF THE CYCLONE.  THIS SHOULD ALLOW PATRICIA TO TURN WESTWARD IN 2-3
DAYS.  THE TRACK GUIDANCE IS IN GOOD AGREEMENT ON TAKING PATRICIA
TOWARD THE SOUTHERN PORTION OF THE BAJA PENINSULA.  HOWEVER...THERE
IS LARGE SPREAD IN THE FORWARD SPEED OF THE CYCLONE DURING THE NEXT
COUPLE OF DAYS.  THE GFS AND UKMET MODELS ARE THE FASTEST AND SHOW
PATRICIA NEAR OR OVER THE SOUTHERN BAJA PENINSULA IN 24-36 HOURS. 
ON THE OTHER HAND...THE ECMWF IS THE SLOWEST AND IT DEPICTS A
WEAKER CYCLONE TURNING WESTWARD WELL SOUTH OF THE PENINSULA.  THE
OFFICIAL FORECAST IS NEAR THE MIDDLE OF THE GUIDANCE ENVELOPE...BUT
IS FASTER AND NORTH OF THE PREVIOUS ADVISORY.  IT SHOULD BE NOTED
THAT THE NEW TRACK FORECAST IS A LITTLE SLOWER THAN THE MODEL
CONSENSUS.

THE CYCLONE IS CURRENTLY IN AN ENVIRONMENT OF LIGHT EASTERLY SHEAR 
AND OVER WARM SSTS.  AS IT MOVES NORTHWARD...IT IS EXPECTED TO
ENCOUNTER INCREASING SOUTHWESTERLY WINDS ALOFT AND A MORE 
STABLE AIRMASS.  THE LGEM...SHIPS...AND GFDL MODELS ARE IN
REASONABLY GOOD AGREEMENT ON A PEAK INTENSITY OF 50-55 KT DURING
THE NEXT COUPLE OF DAYS.  THE HWRF REMAINS A LITTLE STRONGER BUT
IT IS NOT AS STRONG AS PREVIOUS RUNS.  THE OFFICIAL INTENSITY
FORECAST IS IN GOOD AGREEMENT WITH THE STATISTICAL GUIDANCE AND
IS CLOSE TO THE PREVIOUS FORECAST.

INTERESTS IN SOUTHERN BAJA CALIFORNIA SHOULD MONITOR THE PROGRESS OF
PATRICIA.  A TROPICAL STORM WATCH MAY BE REQUIRED FOR A PORTION OF
THE SOUTHERN BAJA PENINSULA LATER TODAY.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      12/0900Z 18.6N 108.9W    40 KT
 12HR VT     12/1800Z 19.7N 109.1W    45 KT
 24HR VT     13/0600Z 21.1N 109.3W    50 KT
 36HR VT     13/1800Z 22.1N 109.4W    50 KT
 48HR VT     14/0600Z 22.8N 109.7W    50 KT
 72HR VT     15/0600Z 23.0N 111.5W    45 KT
 96HR VT     16/0600Z 23.0N 114.0W    35 KT
120HR VT     17/0600Z 23.0N 117.0W    25 KT...REMNANT LOW
 
$$
FORECASTER BROWN
 
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