HURRICANE CHARLEY DISCUSSION NUMBER 13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 AM EDT THU AUG 12 2004

RECENT DATA FROM RECONNAISSANCE AIRCRAFT...SATELLITES...AND RADARS
FROM CUBA INDICATE CHARLEY HAS BECOME BETTER ORGANIZED AND HAS
STRENGTHENED. THE PRESSURE HAS DECREASED TO 983 MB AND FLIGHT-LEVEL
WINDS WERE 83 KT IN THE SOUTHEAST QUADRANT AT 700 MB. BASED ON THIS
INFORMATION AND EARLIER RECON WIND REPORTS INDICATING NEAR 80 KT
SURFACE WINDS...THE ADVISORY INTENSITY HAS BEEN INCREASED TO 80 KT.
UPPER-LEVEL OUTFLOW IS GOOD IN THE NORTHEAST SEMICIRCLE AND IS
IMPROVING TO THE SOUTHWEST.

THE INITIAL MOTION IS 310/15. CHARLEY REMAINS BASICALLY ON THE
PREVIOUS FORECAST TRACK. WHILE THE SPREAD IN THE NHC MODEL GUIDANCE
HAS INCREASED SOMEWHAT FOR THIS ADVISORY PACKAGE...THE CONSENSUS OF
THE MODELS REMAINS VERY CLOSE TO THE PREVIOUS FORECAST TRACK. NOAA
GULFSTREAM-IV DROPSONDE DATA ALONG WITH 12Z UPPER-AIR OBSERVATIONS
INDICATE THE SUBTROPICAL RIDGE OVER SOUTH FLORIDA AND THE
SOUTHEASTERN GULF OF MEXICO IS SLOWLY WEAKENING AND ERODING
EASTWARD. THIS SHOULD ALLOW CHARLEY TO MAKE A GRADUAL TURN TO THE
NORTH-NORTHWEST LATER TODAY AND TURN NORTHWARD BY FRIDAY MORNING
WHEN THE HURRICANE IS NORTH OF WESTERN CUBA. AFTER THAT...CHARLEY
WILL COME UNDER THE INFLUENCE OF A STRONG MID- TO UPPER-LEVEL
TROUGH OVER THE CENTRAL GULF...WHICH WILL ACT TO ACCELERATE THE
HURRICANE NORTH AND NORTH-NORTHEASTWARD BY FRIDAY EVENING. THE
OFFICIAL FORECAST TRACK IS CLOSE TO THE PREVIOUS TRACK...ONLY
SLIGHTLY SLOWER.

THE UPPER-LOW TO THE WEST OF CHARLEY CONTINUES TO MOVE WESTWARD AWAY
FROM THE HURRICANE...WHICH IS LESSENING THE SHEAR. SINCE THE
CENTRAL CORE DEEP CONVECTION AND OUTFLOW HAS IMPROVED...AND THERE
IS AN ABUNDANCE OF WARMER WATER AHEAD...CHARLEY SHOULD CONTINUE TO
INTENSIFY AND COULD POSSIBLY REACH MAJOR HURRICANE STRENGTH BEFORE
IT REACHES WESTERN CUBA. AFTER PASSING OVER CUBA...THE INTENSITY
MAY DROP SLIGHTLY...BUT RE-STRENGTHENING APPEARS LIKELY AS THE
SHEAR IS EXPECTED TO REMAIN LOW ALMOST UP UNTIL LANDFALL OCCURS.
THERE IS A DISTINCT POSSIBILITY THAT CHARLEY COULD BE NEAR MAJOR
HURRICANE STRENGTH WHEN IT MAKES LANDFALL ALONG THE FLORIDA WEST
COAST...ESPECIALLY IF IT MAKES LANDFALL FROM THE TAMPA BAY AREA AND
SOUTHWARD WHERE THE VERTICAL SHEAR WILL BE LESS.

FORECASTER STEWART