Hurricane JIMENA

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HURRICANE JIMENA DISCUSSION NUMBER  20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP132009
800 AM PDT WED SEP 02 2009

SATELLITE IMAGERY SUGGEST THAT AT LEAST THE UPPER-LEVEL CENTER OF
JIMENA IS OVER LAND.  HOWEVER...EARLIER MICROWAVE IMAGERY SUGGESTED
THE VORTEX WAS TILTED WITH HEIGHT TOWARD THE NORTHEAST...AND THERE
ARE NO RECENT MICROWAVE DATA TO PINPOINT THE SURFACE CENTER.  THE
BEST ESTIMATE IS THAT THE SURFACE CENTER HAS PASSED NEAR OR OVER
CABO SAN LAZARO DURING THE PAST FEW HOURS.  THE SATELLITE
PRESENTATION CONTINUES TO SLOWLY DETERIORATE...AND BASED ON THIS
THE INITIAL INTENSITY IS REDUCED TO 85 KT.

THE INITIAL MOTION IS NOW 345/11.  ALL GUIDANCE AGREES ON A
CONTINUED NORTH-NORTHWESTWARD MOTION WITH DECELERATION DURING THE
NEXT 24-36 HR.  AFTER THAT TIME...MOST OF THE GUIDANCE SHOWS JIMENA
TURNING WESTWARD AS HIGH PRESSURE BUILDS NORTH OF THE CYCLONE AND
INCREASING WESTERLY UPPER-LEVEL WINDS SHEAR IT APART.  THE NEW
FORECAST TRACK SHOWS A LITTLE MORE WESTERLY MOTION THAN THE
PREVIOUS TRACK...WITH JIMENA OR ITS REMNANTS FORECAST TO MOVE OVER
THE PACIFIC WEST OF BAJA CALIFORNIA BEFORE DISSIPATING.  THE
GFDN...NOGAPS...AND LBAR MODELS ARE OUTLIERS IN SHOWING AN EASTWARD
TURN...A POSSIBILITY THAT IS NOT CONSIDERED LIKELY AT THIS TIME.

JIMENA SHOULD CONTINUE TO WEAKEN DUE TO LAND INTERACTION...THE
COLDER SEA SURFACE TEMPERATURES WEST OF BAJA CALIFORNIA...AND
INCREASING WESTERLY VERTICAL WIND SHEAR.  THE CYCLONE IS FORECAST
IS WEAKEN TO A TROPICAL STORM IN ABOUT 24 HOURS...TO A TROPICAL
DEPRESSION IN ABOUT 48 HR...AND TO A REMNANT LOW IN ABOUT 72 HR. 
EVEN IF THE CENTER EMERGES OVER THE WARM WATERS OF THE GULF OF
CALIFORNIA...THE FORECAST SHEAR SHOULD PREVENT ANY
RE-INTENSIFICATION.
 
INTERESTS IN THE HURRICANE WARNING AREA ARE ADVISED THAT STRONG
WINDS WILL PRECEDE THE ARRIVAL OF THE CENTER BY SEVERAL HOURS...SO
PREPARATIONS NEED TO BE COMPLETED VERY SOON.  REMEMBER NOT TO FOCUS
ON THE EXACT FORECAST TRACK SINCE DANGEROUS IMPACTS EXTEND SOME
DISTANCE FROM THE CENTER.  THE FORECAST TRACK OF JIMENA IS ALMOST
PARALLEL TO THE COAST OF BAJA CALIFORNIA...AND SMALL DEVIATIONS
LEFT OR RIGHT OF THE TRACK COULD RESULT IN LARGE ERRORS IN BOTH THE
LOCATION AND TIMING OF LANDFALL.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      02/1500Z 25.2N 112.2W    85 KT
 12HR VT     03/0000Z 26.4N 112.7W    75 KT...INLAND
 24HR VT     03/1200Z 27.4N 113.3W    50 KT...INLAND
 36HR VT     04/0000Z 27.8N 113.8W    35 KT...INLAND
 48HR VT     04/1200Z 27.8N 114.5W    30 KT...INLAND
 72HR VT     05/1200Z 27.5N 115.5W    25 KT...REMNANT LOW
 96HR VT     06/1200Z 27.5N 116.5W    20 KT...REMNANT LOW
120HR VT     07/1200Z...DISSIPATED
 
$$
FORECASTER BEVEN
 
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