Tropical Storm DALILA

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TROPICAL STORM DALILA DISCUSSION NUMBER   6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP072007
200 AM PDT MON JUL 23 2007
 
IN THE PAST FEW HOURS...A BURST OF DEEP CONVECTION HAS DEVELOPED
SOUTHWEST OF THE LOW-LEVEL CIRCULATION.  A BANDING FEATURE IS ALSO
TRYING TO FORM...WHICH IS A BIT IMPRESSIVE DUE TO THE 25 KT OF
NORTHEASTERLY SHEAR THE CYCLONE IS CURRENTLY UNDER.  TAFB AND SAB
DVORAK SATELLITE INTENSITY ESTIMATES ARE BOTH 2.5 OR 35 KT.  I WAS
ORIGINALLY GOING TO MAINTAIN THE CYCLONE AS A DEPRESSION...BUT THE
DEEP CONVECTION HAS PERSISTED AND THE OVERALL ORGANIZATION OF THE
SYSTEM HAS CONTINUED TO IMPROVE.   THE INITIAL INTENSITY IS SET AT
35 KT...AND SEVEN-E HAS BEEN UPGRADED TO TROPICAL STORM DALILA.
 
THE INITIAL MOTION IS ESTIMATED AT 290/7.  DALILA REMAINS SOUTH OF
A WEAK MID-LEVEL RIDGE OF HIGH PRESSURE OVER NORTHWESTERN MEXICO...
WITH A MID-LEVEL TROUGH OVER NORTHEASTERN MEXICO.  AS THE RIDGE AND
TROUGH PROGRESS WESTWARD...MOST OF THE GLOBAL MODEL GUIDANCE
CONCURS THAT THE STEERING CURRENTS WILL WEAKEN AND DALILA'S
NORTHWESTWARD MOTION IS EXPECTED TO SLOW FOR THE NEXT COUPLE OF
DAYS.  THEREAFTER...A SLIGHT ACCELERATION TOWARD THE NORTHWEST OR
WEST-NORTHWEST IS ANTICIPATED.  THE OFFICIAL TRACK FORECAST IS VERY
SIMILAR TO THE PREVIOUS ADVISORY AND ALIGNED WITH THE MODEL
CONSENSUS. 

THE CURRENT STRONG NORTHEASTERLY SHEAR IS FORECAST TO ABATE IN 36 TO
48 HOURS...AND DALILA WILL BE IN A MORE CONDUCIVE ENVIRONMENT FOR
STRENGTHENING.  BY DAY FOUR...HOWEVER...THE STORM IS EXPECTED TO
ENCOUNTER COOLER WATERS NORTH OF 20N LATITUDE AND GRADUALLY WEAKEN. 
THE OFFICIAL INTENSITY FORECAST IS A BLEND OF THE SHIPS...GFDL...
AND HWRF SOLUTIONS. 

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      23/0900Z 13.6N 108.6W    35 KT
 12HR VT     23/1800Z 14.1N 109.2W    40 KT
 24HR VT     24/0600Z 14.8N 110.0W    40 KT
 36HR VT     24/1800Z 15.6N 110.7W    45 KT
 48HR VT     25/0600Z 16.5N 111.4W    55 KT
 72HR VT     26/0600Z 18.5N 113.5W    60 KT
 96HR VT     27/0600Z 20.5N 116.5W    55 KT
120HR VT     28/0600Z 22.5N 120.0W    45 KT
 
$$
FORECASTER MAINELLI
 
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