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Tropical Storm DALILA (Text)

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TROPICAL STORM DALILA DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP072007
800 PM PDT MON JUL 23 2007
 
THERE HAS BEEN LITTLE CHANGE WITH THE STRUCTURE OF DALILA THIS
EVENING.  DEEP CONVECTION IS LIMITED TO A SMALL AREA IN THE
SOUTHWEST QUADRANT NEAR THE CENTER...CLOSE ENOUGH AT 00Z TO RESULT
IN A T3.0...45 KT...DVORAK CLASSIFICATION FROM TAFB...ALTHOUGH THE
CONVECTION HAS RETREATED A BIT SINCE THEN.  ON THE OTHER HAND...AN
ASCAT PASS AROUND 1630 UTC SUGGESTED PEAK WINDS OF ONLY AROUND 30
KT. AS A COMPROMISE...THE ADVISORY INTENSITY WILL REMAIN 35 KT.

DALILA HAS BEEN MOVING TO THE RIGHT OF ITS PREVIOUS TRACK AND MOST
OF THE GUIDANCE MODELS...WITH AN INITIAL MOTION OF 340/7. MOST OF
THE GLOBAL MODELS SHOW A WEAK INVERTED MID-LEVEL TROUGH PASSING
NORTH OF DALILA NEAR SOUTHERN BAJA...ERODING THE RIDGING THAT HAD
BEEN STEERING THE CYCLONE ON A MORE WESTERLY TRACK. THE GFS AND
ECMWF SUGGEST THAT A NORTH-NORTHWESTWARD MOTION COULD CONTINUE FOR
ANOTHER 24-36 HOURS AS THE TROUGH PASSES TO THE NORTHWEST OF DALILA
AND ENHANCES A SOUTHERLY STEERING FLOW. AFTER THAT...THE GLOBAL
MODEL CONSENSUS CALLS FOR DALILA TO BEGIN TO FEEL DEEP LAYER
RIDGING OVER THE SOUTHWESTERN UNITED STATES...AND CURVE BACK TO THE
NORTHWEST. THE GUIDANCE SUITE IS A LITTLE LESS CLUSTERED THAN IT
WAS EARLIER TODAY...AND THE GFDN NOW SHOWS A TRACK VERY NEAR THE
BAJA CALIFORNIA PENINSULA. THE OFFICIAL FORECAST HAS BEEN SHIFTED A
LITTLE TO THE RIGHT OF THE PREVIOUS ADVISORY...AND IS IN GOOD
AGREEMENT WITH THE GFS.
 
THE ENVIRONMENTAL SHEAR IS SLOWLY DECREASING...AND SHOULD SOON
PERMIT DALILA TO STRENGTHEN.  BY 72 HOURS...HOWEVER...THE CYCLONE
SHOULD BE NEAR THE 26C SST ISOTHERM...WHEN A WEAKENING TREND IS
EXPECTED TO COMMENCE.  INTENSITY GUIDANCE MODELS ARE LESS
AGGRESSIVE THAN THEY WERE EARLIER...ALL PEAKING A LITTLE BELOW THE
OFFICIAL FORECAST. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      24/0300Z 16.1N 109.3W    35 KT
 12HR VT     24/1200Z 17.1N 109.7W    35 KT
 24HR VT     25/0000Z 18.1N 110.3W    40 KT
 36HR VT     25/1200Z 19.0N 111.0W    45 KT
 48HR VT     26/0000Z 19.8N 111.8W    50 KT
 72HR VT     27/0000Z 22.0N 114.0W    50 KT
 96HR VT     28/0000Z 23.5N 116.5W    40 KT
120HR VT     29/0000Z 24.5N 120.0W    25 KT...DISSIPATING
 
$$
FORECASTER FRANKLIN
 
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