000
WTNT43 KNHC 201454
TCDAT3
 
TROPICAL STORM HARVEY DISCUSSION NUMBER   7
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL082011
1000 AM CDT SAT AUG 20 2011

REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE
THAT HARVEY HAS CHANGED LITTLE IN STRENGTH DURING THE PAST FEW
HOURS....WITH THE INTENSITY REMAINING NEAR 50 KT.  THE AIRCRAFT
REPORTED 61-KT 850 MB FLIGHT-LEVEL WINDS JUST NORTHEAST OF THE
CENTER...WITH RELIABLE-LOOKING SFMR WINDS IN THE 45-50 KT RANGE. 
THE CENTRAL PRESSURE ON THE LAST FIX WAS NEAR 998 MB.  DATA FROM
THE RADAR AT BELIZE CITY SHOWS SOME CONVECTIVE BANDING IN THE
SOUTHERN SEMICIRCLE...BUT THERE IS NO CLOSED EYEWALL APPARENT AT
THIS TIME.

THE CENTER JOGGED TO THE NORTHWEST EARLY THIS MORNING.  HOWEVER...A
MORE WESTWARD MOTION HAS RESUMED AND THE INITIAL MOTION FOR THIS
ADVISORY IS 280/10.  THE SUBTROPICAL RIDGE NORTH OF HARVEY IS
EXPECTED TO STEER IT GENERALLY WESTWARD INTO BELIZE DURING THE NEXT
SEVERAL HOURS...WITH A CONTINUED WESTWARD MOTION THEREAFTER UNTIL
THE CYCLONE EVENTUALLY DISSIPATES.  THE NEW FORECAST TRACK IS IN
THE MIDDLE OF THE GUIDANCE ENVELOPE NEAR THE VARIOUS CONSENSUS
MODELS.

HARVEY HAS AT BEST 4-8 HOURS LEFT TO STRENGTHEN BEFORE LANDFALL. 
WHILE THE CHANCES OF THE CYCLONE REACHING HURRICANE STRENGTH ARE
DIMINISHING...THE INNER WIND CORE IS SMALL AND THUS A 10-15 KT
INCREASE IN STRENGTH CANNOT BE RULED OUT.  HARVEY SHOULD WEAKEN
AFTER LANDFALL...EVENTUALLY DISSIPATING OVER THE MOUNTAINS OF
SOUTHEASTERN MEXICO BETWEEN 48-72 HOURS.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  20/1500Z 16.8N  87.6W   50 KT  60 MPH
 12H  21/0000Z 17.0N  89.0W   45 KT  50 MPH...INLAND
 24H  21/1200Z 17.3N  91.1W   30 KT  35 MPH...INLAND
 36H  22/0000Z 17.6N  93.4W   25 KT  30 MPH...INLAND
 48H  22/1200Z 17.7N  95.6W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  23/1200Z...DISSIPATED
 
$$
FORECASTER BEVEN