Thursday, August 25, 2011

Hurricane Irene Advisory #21A

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WTNT34 KNHC 251745
TCPAT4

BULLETIN
HURRICANE IRENE INTERMEDIATE ADVISORY NUMBER 21A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
200 PM EDT THU AUG 25 2011

...EYE OF IRENE OVER ABACO ISLAND...


SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...26.5N 77.2W
ABOUT 105 MI...170 KM N OF NASSAU
ABOUT 610 MI...980 KM S OF CAPE HATTERAS NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...NNW OR 335 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...951 MB...28.08 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

NONE

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* THE CENTRAL AND NORTHWESTERN BAHAMAS

A HURRICANE WATCH IS IN EFFECT FOR...
* NORTH OF SURF CITY NORTH CAROLINA TO THE NORTH CAROLINA-VIRGINIA BORDER INCLUDING THE PAMLICO...ALBEMARLE...AND CURRITUCK SOUNDS

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* NORTH OF EDISTO BEACH SOUTH CAROLINA TO SURF CITY NORTH CAROLINA

A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA. A WATCH IS TYPICALLY ISSUED 48 HOURS BEFORE THE ANTICIPATED FIRST OCCURRENCE OF TROPICAL-STORM-FORCE WINDS...CONDITIONS THAT MAKE OUTSIDE PREPARATIONS DIFFICULT OR DANGEROUS.

A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 48 HOURS.

WARNINGS WILL LIKELY BE REQUIRED FOR PORTIONS OF THE WATCH AREA LATER TODAY. THE HURRICANE WATCH WILL ALSO LIKELY NEED TO BE EXTENDED NORTHWARD ALONG THE MID-ATLANTIC COAST LATER TODAY. INTERESTS ELSEWHERE IN THE MID-ATLANTIC STATES AND NEW ENGLAND SHOULD MONITOR THE PROGRESS OF IRENE.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 200 PM EDT...1800 UTC...THE CENTER OF HURRICANE IRENE WAS LOCATED NEAR LATITUDE 26.5 NORTH...LONGITUDE 77.2 WEST. IRENE IS MOVING TOWARD THE NORTH-NORTHWEST NEAR 14 MPH...22 KM/H. THIS MOTION IS EXPECTED TO CONTINUE THROUGH TONIGHT WITH A TURN TOWARD THE NORTH BY EARLY FRIDAY. ON THE FORECAST TRACK...THE CORE OF THE HURRICANE WILL MOVE NORTH OF THE NORTHWESTERN BAHAMAS LATER TODAY...AND PASS WELL OFFSHORE OF THE EAST COAST OF CENTRAL AND NORTH FLORIDA TONIGHT AND EARLY FRIDAY. THE HURRICANE IS FORECAST TO APPROACH THE COAST OF NORTH CAROLINA ON SATURDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 115 MPH...185 KM/H...WITH HIGHER GUSTS. IRENE IS A CATEGORY THREE HURRICANE ON THE SAFFIR-SIMPSON HURRICANE WIND SCALE. SOME STRENGTHENING IS POSSIBLE TODAY AND TONIGHT.

IRENE IS A LARGE TROPICAL CYCLONE. HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 70 MILES...110 KM...FROM THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 290 MILES...465 KM.

THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT WAS 951 MB...28.08 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...HURRICANE FORCE WINDS ARE OCCURRING OVER PORTIONS OF THE NORTHWESTERN BAHAMAS. HURRICANE OR TROPICAL STORM FORCE WINDS ARE STILL OCCURRING OVER PORTIONS OF THE CENTRAL BAHAMAS...BUT SHOULD BEGIN TO DIMINISH LATER TODAY. TROPICAL STORM FORCE WINDS ARE POSSIBLE WITHIN THE WATCH AREA ALONG THE COAST OF NORTH AND SOUTH CAROLINA BY LATE FRIDAY.

STORM SURGE...IN AREAS OF ONSHORE WINDS NEAR THE CENTER OF IRENE... AN EXTREMELY DANGEROUS STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH AS 7 TO 11 FEET ABOVE NORMAL TIDE LEVELS OVER THE NORTHWESTERN BAHAMAS. WATER LEVELS WILL GRADUALLY SUBSIDE OVER THE SOUTHEASTERN AND CENTRAL BAHAMAS TONIGHT. NEAR THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DANGEROUS WAVES.

RAINFALL...IRENE IS EXPECTED TO PRODUCE RAINFALL ACCUMULATIONS OF 6 TO 12 INCHES OVER THE NORTHERN BAHAMAS.

SURF...SWELLS GENERATED BY IRENE ARE AFFECTING PORTIONS OF THE COAST OF THE SOUTHEASTERN UNITED STATES. THESE SWELLS WILL CAUSE LIFE-THREATENING SURF AND RIP CURRENT CONDITIONS. PLEASE CONSULT PRODUCTS FROM YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE.

NEXT ADVISORY
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NEXT COMPLETE ADVISORY...500 PM EDT.

$$
FORECASTER BROWN