BULLETIN
TROPICAL STORM EARL ADVISORY NUMBER 15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072010
1100 PM AST SAT AUG 28 2010

...EARL MOVING WESTWARD TOWARD THE LEEWARD ISLANDS...NEW WATCHES AND
WARNINGS ISSUED...

SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.6N 55.4W
ABOUT 520 MI...835 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/HR
PRESENT MOVEMENT...W OR 280 DEGREES AT 20 MPH...32 KM/HR
MINIMUM CENTRAL PRESSURE...989 MB...29.21 INCHES

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

THE GOVERNMENTS OF ANTIGUA AND BARBUDA HAVE ISSUED A HURRICANE
WARNING FOR ANTIGUA...BARBUDA...MONTSERRAT...ST. KITTS...
NEVIS...AND ANGUILLA.

THE GOVERNMENT OF THE NETHERLANDS ANTILLES HAS ISSUED A HURRICANE
WATCH FOR ST. MAARTEN...SABA...AND ST. EUSTATIUS.

THE GOVERNMENT OF ANTIGUA AND BARBUDA HAS ISSUED A HURRICANE WATCH
FOR THE BRITISH VIRGIN ISLANDS.

A HURRICANE WATCH HAS BEEN ISSUED FOR PUERTO RICO AND THE U. S.
VIRGIN ISLANDS...INCLUDING THE ISLANDS OF CULEBRA AND VIEQUES.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* ANTIGUA...BARBUDA...MONTSERRAT...ST. KITTS...NEVIS...AND ANGUILLA

A HURRICANE WATCH IS IN EFFECT FOR...
* ST. MAARTEN...SABA...ST. EUSTATIUS
* BRITISH VIRGIN ISLANDS
* U.S. VIRGIN ISLANDS
* PUERTO RICO INCLUDING THE ISLANDS OF CULEBRA AND VIEQUES

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* SAINT MARTIN AND SAINT BARTHELEMY
* ST. MAARTEN...SABA...ST. EUSTATIUS

A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED
SOMEWHERE WITHIN THE WARNING AREA. A WARNING IS TYPICALLY ISSUED
36 HOURS BEFORE THE ANTICIPATED FIRST OCCURRENCE OF
TROPICAL-STORM-FORCE WINDS...CONDITIONS THAT MAKE OUTSIDE
PREPARATIONS DIFFICULT OR DANGEROUS. PREPARATIONS TO PROTECT LIFE
AND PROPERTY SHOULD BE RUSHED TO COMPLETION.

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 WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

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 1100 PM AST...0300 UTC...THE CENTER OF TROPICAL STORM EARL WAS
LOCATED NEAR LATITUDE 16.6 NORTH...LONGITUDE 55.4 WEST. EARL IS
MOVING TOWARD THE WEST NEAR 20 MPH...32 KM/HR...AND THIS GENERAL
MOTION IS EXPECTED TO CONTINUE WITH A GRADUAL DECREASE IN FORWARD
SPEED ON SUNDAY. A GRADUAL TURN TOWARD THE WEST-NORTHWEST IS
EXPECTED SUNDAY NIGHT AND MONDAY. ON THE FORECAST TRACK...THE
CENTER OF EARL COULD PASS NEAR OR OVER THE NORTHERN LEEWARD ISLANDS
SUNDAY NIGHT OR MONDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 65 MPH...100 KM/HR...WITH HIGHER
GUSTS. STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...AND
EARL IS EXPECTED TO BECOME A HURRICANE ON SUNDAY.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 160 MILES...260 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 989 MB...29.21 INCHES.

HAZARDS AFFECTING LAND
----------------------
WIND...HURRICANE CONDITIONS ARE EXPECTED OVER THE NORTHERN LEEWARD
ISLANDS BY SUNDAY NIGHT. HURRICANE CONDITIONS MAY SPREAD OVER THE
VIRGIN ISLANDS AND PUERTO RICO MONDAY AND MONDAY NIGHT.

STORM SURGE...STORM SURGE WILL RAISE WATER LEVELS 1 TO 3 FEET ABOVE
NORMAL TIDE LEVELS...ACCOMPANIED BY LARGE AND DANGEROUS BATTERING
WAVES...NEAR THE CENTER OF EARL.

RAINFALL...EARL IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS
OF 3 TO 5 INCHES OVER MUCH OF THE NORTHERN LEEWARD ISLANDS...WITH
POSSIBLE MAXIMUM ISOLATED AMOUNTS OF 8 INCHES.

NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...200 AM AST.
NEXT COMPLETE ADVISORY...500 AM AST.

$$
FORECASTER BEVEN

TROPICAL STORM EARL DISCUSSION NUMBER 15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072010
1100 PM AST SAT AUG 28 2010

A NOAA HURRICANE HUNTER FLYING A RESEARCH MISSION INTO EARL REPORTED
FLIGHT-LEVEL AND SFMR WINDS SUPPORTING A INITIAL INTENSITY OF 55
KT. THIS IS IN GOOD AGREEMENT WITH SATELLITE INTENSITY ESTIMATES
FROM TAFB AND SAB OF 55 KT...AND A CIMSS AMSU ESTIMATE OF 56 KT.
THE AIRCRAFT DATA SUGGEST THE CENTRAL PRESSURE IS NEAR 989 MB.
WHILE EARL IS STILL SHOWING SIGNS OF NORTHEASTERLY VERTICAL WIND
SHEAR...THE CONVECTION HAS INCREASED IN BOTH COVERAGE AND
ORGANIZATION DURING THE PAST SEVERAL HOURS.

THE INITIAL MOTION IS 280/17. EARL IS APPROACHING THE END OF A
LOW/MID-LEVEL RIDGE SEPARATING IT FROM HURRICANE DANIELLE...WITH
WATER VAPOR IMAGERY SHOWING AN UPPER-LEVEL TROUGH JUST NORTH OF
CUBA AND HISPANIOLA. THE LARGE-SCALE MODELS FORECAST A LOW-LEVEL
RIDGE TO BUILD TO THE NORTH OF EARL DURING THE NEXT 48-72 HR...
WHILE THE TROUGH REMAINS NEARLY STATIONARY AND POSSIBLY
STRENGTHENS. THE LOW-LEVEL RIDGE WILL STEER EARL GENERALLY TOWARD
THE WEST-NORTHWEST OR WEST WITH SOME DECREASE IN FORWARD
SPEED...WITH THE UPPER TROUGH TRYING TO TURN IT NORTHWARD AS IT
APPROACHES. OVERALL...THIS PATTERN EVOLUTION SHOULD CAUSE EARL TO
MOVE GENERALLY WEST-NORTHWESTWARD FOR 48 HR OR SO...FOLLOWED BY A
GRADUAL TURN TO THE NORTHWEST AND NORTH AS THE TROUGH EXERTS A
GREATER INFLUENCE. THE NEW FORECAST TRACK IS SHIFTED A LITTLE
SOUTH OF THE PREVIOUS TRACK DURING THE FIRST 12 HR BASED ON THE
INITIAL POSITION AND MOTION. AFTER THAT...IT LIES A LITTLE TO LEFT
OF THE CENTER OF THE GUIDANCE ENVELOPE BETWEEN THE CONSENSUS MODELS
AND THE GFDL. THE NEW TRACK IS SIMILAR TO...BUT A LITTLE SOUTH
OF...THE PREVIOUS TRACK.

THE CURRENT NORTHEASTERLY SHEAR SHOULD GRADUALLY DIMINISH OVER THE
NEXT 24 HR AND ALLOW EARL TO STRENGTHEN. THE INTENSITY GUIDANCE IS
IN GOOD AGREEMENT THAT EARL SHOULD BECOME A MAJOR HURRICANE BY 72
HR...IF NOT SOONER...AND THIS IS REFLECTED IN THE NHC FORECAST.
THE INTENSITY FORECAST IS MORE PROBLEMATIC AFTER 72 HR...AS THERE
ARE DISAGREEMENTS IN THE LARGE-SCALE MODELS ON HOW MUCH SHEAR EARL
WILL ENCOUNTER AS IT APPROACHES THE UPPER-LEVEL TROUGH. THE GFS
AND ECMWF FORECAST LIGHT ENOUGH SHEAR TO ALLOW EARL TO MAINTAIN ITS
STRENGTH...WHILE THE UKMET FORECASTS STRONG ENOUGH UPPER-LEVEL
WINDS TO CAUSE EARL TO SHEAR APART. AT THIS TIME...THE INTENSITY
FORECAST COMPROMISES BETWEEN THESE EXTREMES WITH SLOW WEAKENING
AFTER 96 HR.

THE INITIAL AND FORECAST WIND RADII HAVE BEEN SIGNIFICANTLY REVISED
BASED ON THE AIRCRAFT DATA.

THE NEW FORECAST TRACK REQUIRES HURRICANE WARNINGS TO BE ISSUED FOR
PORTIONS OF THE NORTHERN LEEWARD ISLANDS AT THIS TIME. ADDITIONAL
WARNINGS WILL BE REQUIRED ON SUNDAY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 29/0300Z 16.6N 55.4W 55 KT
12HR VT 29/1200Z 17.0N 57.5W 60 KT
24HR VT 30/0000Z 17.5N 60.0W 70 KT
36HR VT 30/1200Z 18.1N 62.0W 80 KT
48HR VT 31/0000Z 19.0N 63.9W 90 KT
72HR VT 01/0000Z 22.0N 68.0W 100 KT
96HR VT 02/0000Z 25.0N 71.0W 105 KT
120HR VT 03/0000Z 31.0N 72.5W 100 KT

$$
FORECASTER BEVEN