HOME	ARCHIVES	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

ZCZC MIATCDEP4 ALL
TTAA00 KNHC DDHHMM
TROPICAL DEPRESSION FOUR-E DISCUSSION NUMBER   2
NATIONAL WEATHER SERVICE MIAMI FL
8 PM PDT FRI JUL 20 2001
 
THE TROPICAL DEPRESSION HAS NOT CHANGED VERY MUCH IN ORGANIZATION
DURING THE PAST FEW HOURS.  THE LOW-LEVEL CENTER IS TO THE NORTH OF
MAIN CONVECTION SUGGESTING THAT THERE IS SOME NORTHERLY SHEAR.
HOWEVER...THE DEPRESSION HAS A LARGE LOW-LEVEL CIRCULATION AND THE
SHEAR IS NOT VERY STRONG.  THEREFORE...A SLOW STRENGTHENING IS
POSSIBLE BEFORE THE TROPICAL CYCLONE MOVES OVER COOL WATERS IN ABOUT
2 DAYS.  THEREAFTER...WEAKENING SHOULD BEGIN.

THE DEPRESSION IS MOVING ABOUT 310/10...AROUND THE SOUTHWESTERN
PERIPHERY OF THE SUBTROPICAL RIDGE AND IS HEADING TOWARD AN AREA OF
WEAKER STEERING CURRENTS CAUSED BY A TROUGH ALONG 125W.  MOST OF THE
NUMERICAL MODELS RESPOND TO THE WEAKNESS IN THE RIDGE BY SLOWING
DOWN THE SYSTEM AND...SOME OF THEM...SUGGEST A GRADUAL TURN MORE TO
THE NORTH.  THE OFFICIAL FORECAST KEEPS THE TROPICAL CYCLONE ON THE
SAME WEST-NORTHWEST TRACK WITH A GRADUAL DECREASE IN FORWARD SPEED.

FORECASTER AVILA
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     21/0300Z 15.0N 118.2W    30 KTS
12HR VT     21/1200Z 16.0N 119.5W    35 KTS
24HR VT     22/0000Z 17.0N 121.0W    40 KTS
36HR VT     22/1200Z 18.0N 122.5W    45 KTS
48HR VT     23/0000Z 19.0N 124.0W    40 KTS
72HR VT     24/0000Z 20.0N 125.5W    30 KTS
 
 
NNNN