000
WTNT43 KNHC 212044
TCDAT3
 
TROPICAL DEPRESSION HARVEY DISCUSSION NUMBER  12
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL082011
400 PM CDT SUN AUG 21 2011
 
VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE THAT THE
LOW-LEVEL CENTER OF HARVEY HAS EMERGED OVER THE EXTREME SOUTHERN
BAY OF CAMPECHE...FARTHER NORTH THAN PREVIOUSLY ESTIMATED.  THE
INITIAL INTENSITY OF 25 KT IS UNCHANGED FROM THE PREVIOUS ADVISORY
AND IS BASED PRIMARILY ON CONTINUITY.  NOW THAT THE CENTER IS BACK
OVER VERY WARM WATERS AND IN A RELATIVELY LOW SHEAR ENVIRONMENT...
THERE IS SOME POTENTIAL FOR STRENGTHENING...ESPECIALLY SINCE THE
LOW-LEVEL CIRCULATION REMAINS FAIRLY WELL DEFINED.  THEREFORE...THE
NEW OFFICIAL FORECAST SHOWS HARVEY STRENGTHENING BACK TO A TROPICAL
STORM BEFORE IT MOVES INLAND OVER MEXICO.
 
THE INITIAL MOTION ESTIMATE IS 290/12.  HARVEY IS EXPECTED TO MOVE
GENERALLY WEST-NORTHWESTWARD IN THE VERY SHORT TERM.  THE TRACK
SHOULD BEND A BIT MORE TO LEFT BEFORE REACHING THE SOUTHEASTERN
COAST OF MEXICO AS HARVEY MOVES UNDERNEATH A DEEP-LAYER RIDGE
CENTERED OVER THE SOUTHERN PLAINS.  THE OFFICIAL NHC TRACK FORECAST
HAS BEEN ADJUSTED NORTHWARD PRIMARILY DUE TO THE CENTER RELOCATION
AND REMAINS ON THE NORTHERN SIDE OF THE GUIDANCE ENVELOPE IN BEST
AGREEMENT WITH THE ECMWF AND GFS MODEL SOLUTIONS.

THIS FORECAST NECESSITATES THE ISSUANCE OF A TROPICAL STORM WARNING
FOR A SMALL PORTION OF MEXICAN COAST BORDERING THE SOUTHWESTERN
GULF OF MEXICO. 

FORECAST POSITIONS AND MAX WINDS
 
INIT  21/2100Z 18.6N  93.8W   25 KT  30 MPH
 12H  22/0600Z 19.0N  95.4W   35 KT  40 MPH
 24H  22/1800Z 19.3N  97.3W   25 KT  30 MPH...INLAND
 36H  23/0600Z 19.5N  99.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 48H  23/1800Z...DISSIPATED
 
$$
FORECASTER KIMBERLAIN/BRENNAN