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TROPICAL DEPRESSION FOUR-E DISCUSSION NUMBER   4
NATIONAL WEATHER SERVICE MIAMI FL
8 PM PDT FRI JUL 23 1999

LATEST SATELLITE INTENSITY ESTIMATES ARE 35...35...AND 30 KT FROM
TAFB...SAB...AND AFWA RESPECTIVELY. THIS SUGGESTS THAT TROPICAL
DEPRESSION FOUR-E IS AT OR NEAR TROPICAL STORM STRENGTH. HOWEVER...
THE LOW LEVEL CIRCULATION IS ELONGATED WEST-NORTHWEST TO EAST-
SOUTHEAST AND...UNLESS THERE IS A TIGHT CENTER HIDDEN UNDER THE
CONVECTION...LOOKS A LITTLE LESS IMPRESSIVE THAN YESTERDAY. IN VIEW
OF THE MIXED SIGNALS...THE CYCLONE WILL REMAIN A DEPRESSION FOR THIS
PACKAGE.

THE INITIAL MOTION REMAINS 275/14. AN UPPER LEVEL TROUGH NORTHWEST
OF THE DEPRESSION IS WEAKENING AND LIFTING TO THE NORTHEAST. THIS IS
ALLOWING A DEEP LAYER RIDGE TO BUILD WESTWARD WITH THE SYSTEM. MOST
LARGE-SCALE AND NHC HURRICANE GUIDANCE INDICATE A GENERAL WESTWARD
MOTION SOUTH OF THIS LARGE RIDGE. THE OUTLIERS ARE THE GFDL AND
UKMET...WHICH TURN THE CYCLONE WEST-SOUTHWEST UNDER THE LARGE RIDGE.
THE OFFICIAL FORECAST CALLS FOR A WESTWARD MOTION AND IS AN UPDATE
OF THE PREVIOUS FORECAST.

THE DEPRESSION REMAINS IN A LIGHT SHEAR ENVIRONMENT...WITH FAIR
OUTFLOW OVER THE WESTERN SEMICIRCLE. THE AVIATION AND SHIPS MODELS
FORECAST THE LIGHT SHEAR TO CONTINUE...WHICH COULD ALLOW THIS SLOW-
DEVELOPING SYSTEM TO REACH TROPICAL STORM STRENGTH. THE OFFICIAL
FORECAST CALLS FOR SLIGHT STRENGTHENING AND IS THE SAME AS THE
PREVIOUS FORECAST. WHILE THE CYCLONE IS FORECAST TO BE OVER 25C SSTS
BY 72 HOURS...THAT PROBABLY WILL HAVE LITTLE EFFECT ON A SYSTEM OF
THIS INTENSITY.
 
 
BEVEN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     24/0300Z 14.0N 137.0W    30 KTS
12HR VT     24/1200Z 14.2N 139.1W    35 KTS
24HR VT     25/0000Z 14.5N 142.0W    40 KTS
36HR VT     25/1200Z 14.8N 144.9W    40 KTS
48HR VT     26/0000Z 15.0N 148.0W    40 KTS
72HR VT     27/0000Z 15.5N 154.5W    40 KTS
 
 
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