000
WTPZ44 KNHC 101434
TCDEP4
TROPICAL DEPRESSION FOUR-E DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP042009
800 AM PDT FRI JUL 10 2009
 
THE DEPRESSION HAS A LARGE AND DISTINCT LOW-LEVEL CIRCULATION WITH
TWO CYCLONICALLY-CURVED HOOKING BANDS. HOWEVER...THE CENTER APPEARS
TO BE LOCATED ON THE NORTHERN PORTION OF AN AREA OF CONVECTION
WHICH IS NOT PARTICULARLY DEEP AT THIS TIME. SATELLITE INTENSITY
ESTIMATES FROM BOTH TAFB AND SAB ARE 2.0 ON THE DVORAK SCALE. THIS
SUPPORTS AN INITIAL INTENSITY OF 30 KT. THE DEPRESSION IS AT LOW
LATITUDES...AND IS FORECAST TO REMAIN EMBEDDED WITHIN AN
ENVIRONMENT OF LIGHT SHEAR AND WARM SSTS...SO THE CYCLONE SHOULD
GRADUALLY INTENSIFY AND BECOME A HURRICANE AS INDICATED IN THE
OFFICIAL FORECAST. MOST OF THE AVAILABLE GUIDANCE BRINGS THE
DEPRESSION TO HURRICANE STATUS BEYOND 3 DAYS. HOWEVER..GIVEN THE
CURRENT STRUCTURE AND FAVORABLE ENVIRONMENT...THIS COULD HAPPEN
EARLIER.
 
THE DEPRESSION IS MOVING WESTWARD A LITTLE FASTER...OR 275 DEGREES
AT ABOUT 10 KNOTS.  THERE IS CURRENTLY A WEAKNESS IN THE
SUBTROPICAL RIDGE NORTHWEST OF THE DEPRESSION...WHICH COULD ALLOW
THE CYCLONE TO MOVE A LITTLE NORTH OF DUE WEST...BUT MOST OF THE
GLOBAL MODELS FORECAST A WESTWARD EXPANSION OF THE RIDGE. THIS
PATTERN SHOULD KEEP THE CYCLONE SOUTH OF THE RIDGE...ON A GENERAL
WEST TO WEST-NORTHWEST TRACK THROUGH FIVE DAYS. IN FACT...THE TRACK
GUIDANCE IS TIGHTLY CLUSTERED INCREASING THE CONFIDENCE IN THE
FORECAST.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      10/1500Z 10.4N 112.8W    30 KT
 12HR VT     11/0000Z 10.5N 114.2W    35 KT
 24HR VT     11/1200Z 10.7N 116.4W    40 KT
 36HR VT     12/0000Z 10.8N 118.7W    45 KT
 48HR VT     12/1200Z 11.3N 121.0W    50 KT
 72HR VT     13/1200Z 12.0N 126.0W    60 KT
 96HR VT     14/1200Z 13.0N 131.0W    70 KT
120HR VT     15/1200Z 13.5N 136.0W    80 KT
 
$$
FORECASTER AVILA