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BULLETIN
TROPICAL DEPRESSION TWELVE ADVISORY NUMBER 1...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT TUE AUG 23 2005

CORRECTED WARNING SECTION

...TWELFTH DEPRESSION OF THE SEASON FORMS OVER THE BAHAMAS...
...TROPICAL STORM WARNINGS ISSUED...

AT 5 PM EDT...2100Z...THE GOVERNMENT OF THE BAHAMAS HAS ISSUED A
TROPICAL STORM WARNING FOR THE CENTRAL AND NORTHWEST BAHAMAS. THIS
INCLUDES CAT ISLAND...THE EXUMAS...LONG ISLAND...RUM CAY...
SAN SALVADOR...NORTHWESTERN BAHAMAS... THE ABACOS... ANDROS ISLAND
...BERRY ISLANDS...BIMINI...ELEUTHERA...GRAND BAHAMA ISLAND...
AND NEW PROVIDENCE.

A TROPICAL STORM OR HURRICANE WATCH MAY BE REQUIRED FOR PORTIONS OF
SOUTHERN FLORIDA LATER TONIGHT.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR LOCAL WEATHER OFFICE.

AT 5 PM EDT...2100Z...THE CENTER OF TROPICAL DEPRESSION TWELVE WAS
ESTIMATED NEAR LATITUDE 23.2 NORTH... LONGITUDE 75.5 WEST OR ABOUT
175 MILES... 280 KM... SOUTHEAST OF NASSAU.

THE DEPRESSION IS MOVING TOWARD THE NORTHWEST NEAR 8 MPH
...13 KM/HR...AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR
THE NEXT 24 HOURS.

MAXIMUM SUSTAINED WINDS INDICATED BY RECONNAISSANCE AIRCRAFT DATA
AND SURFACE OBSERVATIONS ARE NEAR 35 MPH... 55 KM/HR...WITH HIGHER
GUSTS. SOME STRENGTHENING IS FORECAST DURING THE NEXT 24 HOURS...
AND THE DEPRESSION COULD BECOME A TROPICAL STORM BY WEDNESDAY.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB...29.74 INCHES.

TOTAL RAINFALL ACCUMULATIONS OF 3 TO 6 INCHES ARE POSSIBLE OVER
PORTIONS OF THE BAHAMAS...AND ALONG THE NORTHERN COAST OF CUBA...
WITH ISOLATED MAXIMUM AMOUNTS OF 8 INCHES POSSIBLE ALONG THE
NORTHERN COAST OF CUBA.

STORM SURGE FLOODING OF 3 TO 5 FEET ABOVE NORMAL TIDE LEVELS...
ALONG WITH LARGE AND DANGEROUS BATTERING WAVES...CAN BE EXPECTED
NEAR THE CENTER IN AREAS OF ONSHORE WINDS IN THE BAHAMAS.

REPEATING THE 5 PM EDT POSITION...23.2 N... 75.5 W. MOVEMENT
TOWARD...NORTHWEST NEAR 8 MPH. MAXIMUM SUSTAINED
WINDS... 35 MPH. MINIMUM CENTRAL PRESSURE...1007 MB.

AN INTERMEDIATE ADVISORY WILL BE ISSUED BY THE NATIONAL
HURRICANE CENTER AT 8 PM EDT FOLLOWED BY THE NEXT
COMPLETE ADVISORY AT 11 PM EDT.

FORECASTER STEWART

$$

000
WTNT42 KNHC 232108
TCDAT2
TROPICAL DEPRESSION TWELVE DISCUSSION NUMBER 1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT TUE AUG 23 2005

DATA FROM AN AIR FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT...ALONG
WITH OBSERVATIONS FROM THE BAHAMAS AND NEARBY SHIPS...INDICATE THE
BROAD LOW PRESSURE AREA OVER THE SOUTHEASTERN BAHAMAS HAS BECOME
ORGANIZED ENOUGH TO BE CLASSIFIED AS TROPICAL DEPRESSION TWELVE.
THE INITIAL INTENSITY OF 30 KT IS BASED RECON WINDS OF 39 KT AT 800
FT...AND SHIP A8CI9 REPORTING 30-KT SUSTAINED WINDS AT 18Z IN THE
NORTHEAST QUADRANT. UPPER-LEVEL OUTFLOW IS WEAK...BUT IMPROVING AS
A SMALL ANTICYCLONE HAS BEEN DEVELOPING ABOVE THE LOW-LEVEL CENTER.

THE INITIAL MOTION ESTIMATE IS AN UNCERTAIN 310/07. THE LOW-LEVEL
CENTER HAS BEEN REFORMING WITHIN A LARGE CLEAR AREA NOTED IN
SATELLITE IMAGERY. HOWEVER...FLIGHT-LEVEL RECON WINDS CLEARLY
INDICATE A BROAD BUT OTHERWISE WELL-DEFINED LOW-LEVEL WIND FIELD.
THERE HAVE BEEN SEVERAL SMALL VORTICES DEVELOP WITHIN THE
CONVECTION IN THE EASTERN SEMICIRCLE AND THEN ROTATE WESTWARD OUT
FROM UNDER THE CONVECTION. THE INITIAL POSITION IS ROUGHLY THE
GEOMETRIC CENTER OF ALL THE SMALL SWIRLS...BUT SOME RE-ORGANIZATION
OF THE CENTER WITHIN THE CONVECTION IS POSSIBLE. TD-12 IS EXPECTED
TO CONTINUE MOVING SLOWLY NORTHWESTWARD TOWARD A WEAKNESS IN THE
MID-LEVEL SUBTROPICAL RIDGE. THIS WEAKNESS SHOWS UP BEST IN 500 MB
DATA...AND THEN DISAPPEARS BELOW AND ABOVE THAT LEVEL. BY 36-48
HOURS...ALL OF THE GLOBAL MODELS AND THE GFDL MODEL FORECAST THE
WEAKNESS TO FILL AND BE REPLACED BY A BROAD EAST-WEST ORIENTED
RIDGE. THIS SHOULD HELP TO DRIVE THE CYCLONE MORE WESTWARD ACROSS
SOUTHERN FLORIDA IN 60-72 HOURS...AND THEN INTO THE EASTERN GULF OF
MEXICO BY 96 HOURS. THIS SCENARIO IS CONSISTENT WITH THE NHC MODEL
CONSENSUS AND THE DEVELOPING SYNOPTIC PATTERN.

THE INTENSITY FORECAST IS A LITTLE TRICKY DUE TO THE UNCERTAINTY ON
EXACTLY WHEN A WELL-DEFINED CENTER WILL DEVELOP AND HOW SOON
CONVECTION WRAPS AROUND THE WEST SIDE OF THE CIRCULATION. THE
UPPER-LEVEL FLOW IS FORECAST TO REMAIN STRONGLY DIFLUENT FROM THE
NORTH FOR THE NEXT 24-36 HOURS...AND THEN BECOME NORTHEASTERLY TO
EASTERLY AFTER THAT. SINCE THE SHEAR IS ALSO FORECAST TO REMAIN
RELATIVELY LOW AT AROUND 10 KT AND SSTS WILL BE NEAR 31C UNDER THE
CENTER...AT LEAST STEADY INTENSIFICATION APPEARS TO BE IN ORDER. IF
CENTRAL CONVECTION DEVELOPS WITHIN THE NEXT 24 HOURS...THEN THIS
SYSTEM COULD REACH HURRICANE STRENGTH BEFORE IT MAKES LANDFALL. THE
OFFICIAL INTENSITY FORECAST IS SLIGHTLY LOWER THAN THE SHIPS MODEL.

THE NWS RULES GOVERNING THE NAMING OF TROPICAL CYCLONES SPECIFY
THAT...WITHIN A BASIN...WHEN A CYCLONE FORMS FROM THE REMNANT OF A
PREVIOUSLY EXISTING CYCLONE...THE OLD NAME/NUMBER IS RETAINED.
TROPICAL DEPRESSION TWELVE HAS A COMPLEX GENESIS THAT LIKELY
INCLUDES A MID-LEVEL REMNANT OF FORMER TROPICAL DEPRESSION TEN. A
REVIEW OF SATELLITE AND RAWINSONDE DATA OVER THE PAST WEEK OR SO
SUGGESTS THAT A SECOND DISTURBANCE APPROACHED AND COMBINED WITH THE
MID-LEVEL REMNANT OF TROPICAL DEPRESSION TEN ON 20 AUGUST. BECAUSE
IT IS IMPOSSIBLE TO DETERMINE WHICH OF THESE TWO SYSTEMS IS
ASSOCIATED WITH TODAY'S GENESIS...WE HAVE ELECTED TO USE THE
DESIGNATION TWELVE RATHER THAN TEN FOR THE NEW DEPRESSION. THIS
SITUATION DIFFERS FROM LAST YEAR'S REGENERATION OF IVAN...IN WHICH
THE LOW-LEVEL REMNANT OF THAT SYSTEM REMAINED A DISTINCT FEATURE
THAT COULD BE FOLLOWED CONTINUOUSLY UNTIL IT REGENERATED.

FORECASTER STEWART