Saturday, September 06, 2008

Tropical Storm Hanna Update 4








ZCZC MIATCDAT3 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM HANNA DISCUSSION NUMBER 40
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082008
500 PM EDT SAT SEP 06 2008

THE CENTER OF HANNA IS MOVING OVER THE DELMARVA PENINSULA...
WITH RADAR DATA CONTINUING TO SHOW WIDESPREAD RAINBANDS OVER THE
NORTHERN SEMICIRCLE. HOWEVER...THE CENTRAL CONVECTION IS
DECREASING...AND THE CENTRAL PRESSURE HAS RISEN TO 994 MB.
RECENT SURFACE OBSERVATIONS HAVE SHOWN 35-40 KT SUSTAINED WINDS.
SO...THE MAXIMUM INTENSITY IS MAINTAINED AT 45 KT ON THE PREMISE
THAT THE MAXIMUM WINDS WERE NOT SAMPLED. AS BEFORE...WHILE LITTLE
CHANGE IN STRENGTH IS LIKELY THROUGH THE FORECAST PERIOD...HANNA IS
EXPECTED TO LOSE TROPICAL CHARACTERISTICS IN 12-24 HOURS.

THE INITIAL MOTION IS NOW 040/23. HANNA IS ENTERING THE WESTERLIES
AND SHOULD ACCELERATE NORTHEASTWARD FOR THE NEXT 24-36 HR..FOLLOWED
BY A RAPID EASTWARD MOTION. A TURN TOWARD THE NORTHEAST WITH SOME
DECELERATION IS POSSIBLE AFTER 96 HR. THE MODEL GUIDANCE IS FAIRLY
WELL CLUSTERED AROUND THIS SCENARIO...AND THE NEW FORECAST TRACK IS
ESSENTIALLY AN UPDATE OF THE PREVIOUS TRACK.

FORECAST POSITIONS AND MAX WINDS

INITIAL 06/2100Z 38.5N 75.8W 45 KT...INLAND
12HR VT 07/0600Z 41.7N 71.8W 45 KT...INLAND
24HR VT 07/1800Z 45.3N 64.6W 45 KT...EXTRATROPICAL
36HR VT 08/0600Z 48.3N 56.0W 45 KT...INLAND EXTRATROPICAL
48HR VT 08/1800Z 49.6N 47.2W 45 KT...EXTRATROPICAL
72HR VT 09/1800Z 51.5N 31.0W 45 KT...EXTRATROPICAL
96HR VT 10/1800Z 56.0N 17.5W 45 KT...EXTRATROPICAL
120HR VT 11/1800Z 60.0N 10.0W 45 KT...EXTRATROPICAL

$$
FORECASTER BEVEN

NNNN

-------------------------------------------------------------------------------------

000
WTNT33 KNHC 062032
TCPAT3
BULLETIN
TROPICAL STORM HANNA ADVISORY NUMBER 40
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082008
500 PM EDT SAT SEP 06 2008

AT 5 PM EDT...2100 UTC...THE TROPICAL STORM WARNING IS DISCONTINUED
SOUTH OF THE NORTH CAROLINA/VIRGINIA BORDER. A TROPICAL STORM
WARNING IS NOW IN EFFECT FROM NORTH OF THE NORTH CAROLINA/VIRGINIA
BORDER TO MERRIMACK RIVER MASSACHUSETTS...INCLUDING PAMLICO AND
ALBEMARLE SOUNDS...ALL OF CHESAPEAKE BAY...THE TIDAL POTOMAC...
WASHINGTON D.C...DELAWARE BAY...NEW YORK HARBOR...LONG ISLAND
SOUND...BLOCK ISLAND...MARTHA'S VINEYARD AND NANTUCKET. A TROPICAL
STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED
WITHIN THE WARNING AREA WITHIN THE NEXT 24 HOURS.

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

AT 500 PM EDT...2100Z...THE CENTER OF TROPICAL STORM HANNA WAS
LOCATED NEAR LATITUDE 38.5 NORTH...LONGITUDE 75.8 WEST OR JUST EAST
OF CAMBRIDGE MARYLAND. THIS POSITION IS ALSO ABOUT 40 MILES...
65 KM...WEST-NORTHWEST OF OCEAN CITY MARYLAND AND ABOUT 100 MILES...
155 KM...SOUTHWEST OF ATLANTIC CITY NEW JERSEY.

HANNA IS MOVING TOWARD THE NORTHEAST NEAR 28 MPH...44 KM/HR. THIS
GENERAL MOTION IS EXPECTED TO CONTINUE WITH AN INCREASE IN FORWARD
SPEED DURING THE NEXT COUPLE OF DAYS. ON THE FORECAST TRACK...THE
CENTER OF HANNA WILL CROSS THE EASTERN MID-ATLANTIC STATES THIS
EVENING...AND MOVE NEAR OR OVER SOUTHERN NEW ENGLAND SUNDAY
MORNING. THE CENTER IS FORECAST TO PASS NEAR OR OVER THE CANADIAN
MARITIMES SUNDAY AFTERNOON.

MAXIMUM SUSTAINED WINDS ARE NEAR 50 MPH...85 KM/HR...WITH HIGHER
GUSTS. LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE NEXT COUPLE
OF DAYS. HOWEVER...HANNA IS FORECAST TO LOSE TROPICAL
CHARACTERISTICS ON SUNDAY.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 200 MILES...325 KM
FROM THE CENTER. WALLOPS ISLAND VIRGINIA RECENTLY REPORTED A WIND
GUST OF 54 MPH...87 KM/HR.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 994 MB...29.35 INCHES.

STORM SURGE FLOODING OF 1 TO 3 FEET ABOVE NORMAL TIDE LEVELS...WITH
LOCALLY HIGHER LEVELS IN BAYS AND ACCOMPANIED BY LARGE AND DANGEROUS
BATTERING WAVES...IS EXPECTED IN THE WARNING AREA. COASTAL STORM
SURGE FLOODING ALONG THE ATLANTIC COASTS OF SOUTH CAROLINA AND
NORTH CAROLINA...INCLUDING THE PAMLICO AND ABLEMARLE SOUNDS...
SHOULD GRADUALLY SUBSIDE TODAY.

HANNA IS EXPECTED TO PRODUCE RAINFALL ACCUMULATIONS OF 3 TO 6 INCHES
FROM THE NORTHERN MID-ATLANTIC STATES NORTHEASTWARD THROUGH NEW
ENGLAND...WITH ISOLATED MAXIMUM AMOUNTS OF 8 INCHES POSSIBLE.
THESE RAINFALL AMOUNTS COULD PRODUCE FLASH FLOODING ACROSS THESE
REGIONS.

ISOLATED TORNADOES ARE POSSIBLE TONIGHT OVER THE COASTAL AREAS OF
SOUTHERN NEW ENGLAND.

REPEATING THE 500 PM EDT POSITION...38.5 N...75.8 W. MOVEMENT
TOWARD...NORTHEAST NEAR 28 MPH. MAXIMUM SUSTAINED WINDS...50 MPH.
MINIMUM CENTRAL PRESSURE...994 MB.

AN INTERMEDIATE ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE
CENTER AT 800 PM EDT FOLLOWED BY THE NEXT COMPLETE ADVISORY AT 1100
PM EDT.

$$
FORECASTER BEVEN

0 Comments:

Post a Comment

<< Home