000
WTNT43 KNHC 050900
TCDAT3
TROPICAL STORM HANNA DISCUSSION NUMBER  34
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL082008
500 AM EDT FRI SEP 05 2008
 
A RECONNAISSANCE AIRCRAFT CURRENTLY SAMPLING HANNA RECENTLY FOUND
PEAK FLIGHT-LEVEL WINDS OF 73 KT.  THIS WOULD NORMALLY CORRESPOND
TO SURFACE WINDS OF ABOUT 60 KT USING THE STANDARD REDUCTION. 
HOWEVER...THE WINDS WERE FOUND IN AN AREA ABSENT OF DEEP CONVECTION
AND THE SFMR INSTRUMENT ONLY SHOWED ABOUT 51 KT IN THE SAME AREA.
IN ADDITION...A DROPSONDE RELEASED IN THE AREA HAD A SURFACE WIND
OF 57 KT.  THESE DATA SUGGEST THE INTENSITY REMAINS NEAR 55 KT. 
HANNA HAS BEEN STRUGGLING TO GENERATE PERSISTENT DEEP CONVECTION
NEAR THE CENTER DUE TO SHEAR AND DRY AIR...ALTHOUGH THERE HAS BEEN
A RECENT BURST WITHIN THE LAST COUPLE OF HOURS.  WHILE THERE IS
SOME POTENTIAL FOR A LITTLE ADDITIONAL STRENGTHENING...ALL BUT ONE
OF THE INTENSITY MODELS KEEP HANNA JUST BELOW HURRICANE STRENGTH. 
STILL...THERE IS LITTLE DIFFERENCE BETWEEN A STRONG TROPICAL STORM
AND A CATEGORY ONE HURRICANE...AND HANNA COULD REACH HURRICANE
STRENGTH BEFORE MOVING INLAND OVER THE SOUTHEASTERN UNITED STATES
IN ABOUT 24 HOURS.
 
HANNA IS BEING STEERED BY THE SUBTROPICAL RIDGE OVER THE WESTERN
ATLANTIC RESULTING IN A MOTION TOWARD THE NORTHWEST OR 320/17. 
HANNA IS EXPECTED TO TURN TOWARD THE NORTH TODAY THEN NORTHEASTWARD
TONIGHT AND TOMORROW AS IT ROUNDS THE WESTERN PERIPHERY OF THE
RIDGE.  THEREAFTER...HANNA IS EXPECTED TO RACE NORTHEASTWARD AND
BECOME EXTRATROPICAL IN ABOUT 3 DAYS.  TRACK MODELS HAVE BEEN
TRENDING TOWARD THE WEST AND THE OFFICIAL FORECAST IS SHIFTED TO
THE LEFT THROUGH 36 HOURS.  HOWEVER...GIVEN HANNA'S LARGE
SIZE...ONE SHOULD NOT FOCUS ON THE EXACT TRACK AS THE INCLEMENT
WEATHER EXTENDS WELL BEYOND THE CENTER. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/0900Z 28.0N  78.0W    55 KT
 12HR VT     05/1800Z 30.0N  78.8W    60 KT
 24HR VT     06/0600Z 33.2N  79.1W    60 KT
 36HR VT     06/1800Z 36.7N  77.2W    45 KT...INLAND
 48HR VT     07/0600Z 40.6N  72.9W    40 KT...INLAND
 72HR VT     08/0600Z 48.0N  58.0W    40 KT...EXTRATROPICAL
 96HR VT     09/0600Z 50.5N  40.0W    40 KT...EXTRATROPICAL
120HR VT     10/0600Z 51.5N  23.5W    40 KT...EXTRATROPICAL
 
$$
FORECASTER RHOME