Caribbean - Central America Weather

[Gustywind]

Almost at 20N!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

BULLETIN
HURRICANE BILL ADVISORY NUMBER 18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 PM AST WED AUG 19 2009

...BILL REMAINS AN EXTREMELY DANGEROUS CATEGORY 4 HURRICANE...NOW
MOVING NORTHWESTWARD...

INTERESTS IN THE NORTHERN LEEWARD ISLANDS AND BERMUDA SHOULD MONITOR
THE PROGRESS OF BILL.

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 OF THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR NATIONAL METEOROLOGICAL SERVICE.

AT 500 PM AST...2100 UTC...THE CENTER OF HURRICANE BILL WAS LOCATED
NEAR LATITUDE 19.8 NORTH...LONGITUDE 57.6 WEST OR ABOUT 335 MILES...
535 KM...NORTHEAST OF THE LEEWARD ISLANDS AND ABOUT 970 MILES...1565
KM...SOUTH-SOUTHEAST OF BERMUDA.

BILL IS MOVING TOWARD THE NORTHWEST NEAR 20 MPH...32 KM/HR...AND
THIS GENERAL MOTION IS EXPECTED FOR THE NEXT DAY OR SO WITH A TURN
TOWARD THE NORTH-NORTHWEST FORECAST BY LATE FRIDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 135 MPH...215 KM/HR...WITH HIGHER
GUSTS. BILL IS A CATEGORY FOUR HURRICANE ON THE SAFFIR-SIMPSON
SCALE. SOME ADDITIONAL STRENGTHENING IS POSSIBLE DURING THE NEXT
COUPLE OF DAYS.

BILL IS A LARGE TROPICAL CYCLONE. HURRICANE FORCE WINDS EXTEND
OUTWARD UP TO 85 MILES...140 KM...FROM THE CENTER...AND TROPICAL
STORM FORCE WINDS EXTEND OUTWARD UP TO 230 MILES...370 KM.

THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY AN AIR FORCE RESERVE
HURRICANE HUNTER AIRCRAFT WAS 947 MB...27.96 INCHES.

LARGE SWELLS ASSOCIATED WITH BILL WILL BE IMPACTING THE ISLANDS OF
THE NORTHEAST CARIBBEAN SEA DURING THE NEXT DAY OR TWO. LARGE
SWELLS ASSOCIATED WITH BILL SHOULD ALSO BEGIN TO AFFECT BERMUDA AND
PORTIONS OF THE EASTERN COAST OF THE UNITED STATES FRIDAY AND
SATURDAY.

...SUMMARY OF 500 PM AST INFORMATION...
LOCATION...19.8N 57.6W
MAXIMUM SUSTAINED WINDS...135 MPH
PRESENT MOVEMENT...NORTHWEST OR 305 DEGREES AT 20 MPH
MINIMUM CENTRAL PRESSURE...947 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
1100 PM AST.

$$
FORECASTER BLAKE

Yuppiiii Tkanks GOD BILL IS MOVING AWAY we escape from maybe (hope it's the last, but the peak of the season has just began) one of the strongest cane of this season! Right now let's se what happens with the strong waves expected in our area...up to 3 to 4 meters here. Moreover, should i add some outer bands of rain shower associated with Bill for tommorow; but given its actual movement more NW maybe nothing too?...
Stay safe all, that's really a nice outcome for all of us in the islands : no direct hit
Gustywind

[msbee]

You know, I seriously doubt at this point that we are going to even get any rain from this cane.
Count our blessings folks
We are already starting to see swells come in. Our south facing harbour is empty of all boats and is getting churned up a good bit.
South west side of the island is starting to get choppy too.

[expat2carib]

My thoughts are with the people on it's track. It's a monster.

I really hope it's a fish.

[msbee]

yes, I worry about Bermuda now

[cycloneye]

It reached 20n

Yes,we are out of danger of a direct hit.Now prayers go to those people in Bermuda and upstream in New England,Nova Scotia and Newfoundland.

[msbee]

[mpic]

Congratulations! I have tears in my eyes.

[Gustywind]

You know, I seriously doubt at this point that we are going to even get any rain from this cane.
Count our blessings folks
We are already starting to see swells come in. Our south facing harbour is empty of all boats and is getting churned up a good bit.
South west side of the island is starting to get choppy too.

Yeah, right the indirect effets are the main story right now, hope nothing too strong in your island and for the others too!!!
Humm... off topic, beautiful pics Msbee... looks like paradise

[abajan]

:woo:

Ahh... msbee, those celebrations might be a tad premature. I'll never forget about an incident that occurred about 15 years ago when a hurricane named Iris, not nearly as powerful as Bill presently is, passed Barbados to its north and everyone here thought that was that. Well, the next day a severe feeder band seemed to come out of nowhere and within a matter of just 5 minutes or so, the winds increased from around a paltry 15 mph to way in excess of 50 mph out of the southwest. The skies darkened, the rain poured and it thundered like crazy.

Another incident I can recall happened in Trinidad & Tobago when a feeder band from a hurricane named Gabrielle, whose eye never got any closer to them than about a thousand miles, caused severe thunderstorms, strong winds and even a tornado.

Don't let your guard down just yet.

[msbee]

Gee thanks, abajan
You sure know how to spoil a good party LOL

actually, you have a point about those feeder bands.
And I remember Tropical storm Klaus in 1984..
Hurricane Klaus was an Atlantic hurricane that hit the Leeward Islands from the west in November of the 1984 Atlantic hurricane season. Forming from a broad area of low pressure on November 5, Klaus maintained a northeast movement throughout much of its path. After making landfall on extreme eastern Puerto Rico, it passed to the north of the Leeward Islands, resulting in strong southwesterly winds and rough seas. Klaus attained hurricane status and reached peak winds of 90 mph (145 km/h) before becoming extratropical over cooler waters on November 13. The storm dropped heavy rainfall in Puerto Rico, causing minor flooding and light damage. Klaus caused heavy marine damage in the Leeward Islands, including wrecking at least three ships. The Virgin Islands experienced heavy damage as well.
Tropical Storm Klaus made landfall on extreme eastern Puerto Rico early on November 7. The storm passed a short distance north of the Lesser Antilles, and became the first tropical cyclone in recorded history to affect the islands from the west.

[cycloneye]

What we were celebrating was that a direct hit was not in the cards anymore.But yes,feederbands are many times dangerous,so lets watch for that.

[Gustywind]

000
WTNT43 KNHC 192031
TCDAT3
HURRICANE BILL DISCUSSION NUMBER 18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 PM AST WED AUG 19 2009

VISIBLE SATELLITE IMAGES SHOW THAT BILL IS AN IMPRESSIVE HURRICANE
WITH MESOCYCLONES NOTED IN THE EYE...CURVED BANDING FEATURES IN ALL
QUADRANTS AND A WELL-ESTABLISHED OUTFLOW PATTERN. AN FORCE RESERVE
HURRICANE HUNTER RECENTLY MEASURED 135 KT AT 700 MB...ALONG WITH
SFMR WINDS OF 103 KT AND A MINIMUM PRESSURE OF 947 MB. IN
ADDITION...THERE WAS AN SFMR MEASUREMENT OF 106 KT FROM THE NOAA
MISSION THIS MORNING. SATELLITE CLASSIFICATION ARE 127 KT FROM
TAFB/SAB AND THE INITIAL INTENSITY IS KEPT AT 115 KT AS A
COMPROMISE OF ALL THESE DATA.

VERY WARM WATERS ARE ALONG THE PATH OF THE HURRICANE FOR THE NEXT
FEW DAYS. THE BIGGEST QUESTION IS WHETHER THE UPPER ENVIRONMENT
WILL REMAIN FAVORABLE FOR STRENGTHENING. A PAIR OF UPPER-LEVEL
TROUGHS HAVE THE POTENTIAL TO INDUCE SOME SHEAR ON BILL...ONE ALONG
60W AND OTHER AT ABOUT 70W. WHILE THE MODELS DISAGREE ON WHETHER
THE FIRST TROUGH WILL AFFECT THE HURRICANE MUCH...MOST MODELS SHOW
SOUTHWESTERLY SHEAR INCREASING IN A COUPLE DAYS AS A RESULT OF THE
SECOND FEATURE. IN ADDITION...AN EYEWALL REPLACEMENT CYCLE COULD
OCCUR AT ANY TIME WITH A SECONDARY WIND MAXIMUM NOTED AT ABOUT 75 N
MI FROM THE CENTER IN AIRCRAFT DATA. REGARDLESS...ALL OF THE
RELIABLE MODELS KEEP THE HURRICANE QUITE STRONG FOR THE NEXT
SEVERAL DAYS...AND THE OFFICIAL INTENSITY FORECAST REFLECTS THAT
LIKELIHOOD.

THE ESTIMATED MOTION IS A LITTLE MORE TO THE RIGHT AND FASTER...NOW
305/17. STRONG SUBTROPICAL RIDGING SHOULD KEEP BILL ON THIS
GENERAL TRACK FOR THE NEXT COUPLE OF DAYS WITH A GRADUAL BEND TOWARD
THE NORTH-NORTHWEST BY THE WEEKEND AS THE HURRICANE MOVES INTO A
BREAK IN THE RIDGE. SOME OF THE MODELS...SUCH AS THE GFS...NOW
SHOW A SLIGHTLY STRONGER RIDGE OVER THE WESTERN ATLANTIC AND A
SLOWER MID-LATITUDE TROUGH MOVING ACROSS THE EASTERN UNITED STATES.
IF THIS SOLUTION IS CORRECT...BILL WOULD BE ABLE TO MOVE A LITTLE
FARTHER TO THE WEST BEFORE TURNING TO THE NORTH AND NORTHEAST.
THERE HAS BEEN A SMALL WESTWARD SHIFT IN MOST OF THE AFTERNOON
MODEL GUIDANCE...AND THE OFFICIAL FORECAST IS SHIFTED IN THAT
DIRECTION. THIS IS A GOOD TIME TO POINT OUT THAT THERE IS A LOT OF
UNCERTAINTY IN THE LONG-RANGE TROPICAL CYCLONE FORECAST AND ONE
SHOULD NOT FOCUS ON THE EXACT TRACK AT THOSE TIME PERIODS.

BECAUSE BILL IS A LARGE AND STRONG HURRICANE...SWELLS TRIGGERED BY
THE HURRICANE SHOULD AFFECT THE NORTHERN LEEWARD ISLANDS...THE
BAHAMAS...BERMUDA AND MOST OF THE EASTERN UNITED STATES DURING
THE NEXT FEW DAYS. THESE SWELLS WILL LIKELY CAUSE EXTREMELY
DANGEROUS SURF AND LIFE-THREATENING RIP CURRENTS. PLEASE CONSULT
STATEMENTS ISSUED BY YOUR LOCAL WEATHER OFFICE FOR MORE DETAILS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 19/2100Z 19.8N 57.6W 115 KT
12HR VT 20/0600Z 21.1N 59.7W 120 KT
24HR VT 20/1800Z 23.0N 62.4W 125 KT
36HR VT 21/0600Z 25.2N 64.6W 120 KT
48HR VT 21/1800Z 27.9N 66.6W 120 KT
72HR VT 22/1800Z 34.0N 69.0W 110 KT
96HR VT 23/1800Z 42.0N 65.5W 95 KT
120HR VT 24/1800Z 51.5N 50.5W 55 KT...EXTRATROPICAL

$$
FORECASTER BLAKE

[Gustywind]

BILL: THE MONSTER...moving away from the Lesser Antilles [img]

http://www.goes.noaa.gov/EVENTS/EG14.JPG[/img]

Right now, we're watching carefully if some feederbands could reach the islands...we never know!

[Gustywind]

000
AXNT20 KNHC 192324
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED AUG 19 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2230 UTC.

...SPECIAL FEATURES...
HURRICANE BILL REMAINS A CATEGORY FOUR HURRICANE ON THE
SAFFIR-SIMPSON SCALE WITH MAXIMUM SUSTAINED WINDS SPEEDS OF 115
KT WITH GUSTS UP TO 140 KT. THE CENTER OF HURRICANE BILL WAS
LOCATED NEAR 19.8N 57.6W OR ABOUT 335 MILES...535 KM...NE OF THE
LEEWARD ISLANDS AND ABOUT 970 MILES...1565 KM...SSE OF BERMUDA
MOVING NW NEAR 17 KT. THE ESTIMATED CENTRAL PRESSURE IS 947 MB.
BILL IS A LARGE SYSTEM WITH HURRICANE FORCE WINDS EXTENDING
OUTWARD FROM THE CENTER UP TO 85 MILES...140 KM...AND WITH
TROPICAL STORM FORCE WINDS EXTENDING OUTWARD UP TO 230
MILES...370 KM. ADDITIONAL STRENGTHENING IS POSSIBLE DURING THE
NEXT COUPLE OF DAYS. LARGE SWELLS ASSOCIATED WITH BILL WILL
START TO IMPACT ISLANDS IN THE NE CARIBBEAN DURING THE NEXT DAY
OR TWO...AND WILL BEGIN TO AFFECT BERMUDA AND PORTIONS OF THE E
COAST OF THE UNITED STATES FRIDAY AND SATURDAY. PLEASE READ THE
LATEST FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS TCMAT3/WTNT23
KNHC FOR MORE DETAILS. NUMEROUS MODERATE/STRONG CONVECTION IS
FROM 18N-21N BETWEEN 55W-60W. NUMEROUS MODERATE/SCATTERED STRONG
CONVECTION IS FROM 22N-25N BETWEEN 53W-59W....TROPICAL WAVES...
A TROPICAL WAVE IS APPROACHING THE CAPE VERDE ISLANDS EXTENDING
FROM 15N22W TO 9N19W MOVING W NEAR 10 KT. THIS WAVE COINCIDES
WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED IN TOTAL
PRECIPITABLE WATER IMAGERY. SATELLITE DERIVED WINDS ALSO
INDICATE LOW/MID-LEVEL CYCLONIC FLOW IN THE VICINITY OF THE WAVE
AXIS. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE.

A TROPICAL WAVE EXTENDS FROM 15N46W TO 8N43W MOVING W NEAR 20
KT. THIS WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM
OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. SATELLITE IMAGERY
INDICATES AN INVERTED-V STRUCTURE IN THE LOW-LEVEL CLOUDS.
SATELLITE DERIVED WINDS ALSO INDICATE CYCLONIC TURNING IN THE
VICINITY OF THE WAVE AXIS. A DRY SAHARAN AIR LAYER LIES TO THE E
OF THE WAVE AXIS INHIBITING ANY DEEP CONVECTION.

A TROPICAL WAVE IS ALONG 84W S OF 19N MOVING W NEAR 15 KT. THIS
WAVE ORIGINATED AS THE REMNANTS OF ANA THAT DISSIPATED A FEW
DAYS AGO. THIS WAVE LIES UNDER A DIFFLUENT ZONE ALOFT WHICH IS
ENHANCING SCATTERED MODERATE/ISOLATED STRONG CONVECTION ACROSS
CENTRAL AMERICA FROM 8N-17N BETWEEN 78W-86W.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 12N15W 10N30W 12N43W 9N48W
12N56W 10N61W. SCATTERED MODERATE/STRONG CONVECTION IS JUST
INLAND OVER AFRICA FROM 10N-13N BETWEEN 13W-16W. A CLUSTER OF
SCATTERED MODERATE/STRONG CONVECTION IS FROM 11N-12N BETWEEN
24W-26W. ISOLATED MODERATE CONVECTION IS WITHIN 150 NM N AND 200
NM S OF THE AXIS BETWEEN 22W-32W.

...DISCUSSION...

THE GULF OF MEXICO...
A WEAK SURFACE RIDGE IS ACROSS THE GULF OF MEXICO TONIGHT.
HOWEVER...SHOWERS/THUNDERSTORMS ARE AFFECTING MUCH OF THE BASIN
DUE TO UPPER LEVEL FEATURES. ISOLATED SHOWERS/THUNDERSTORMS ARE
ACROSS THE NRN GULF N OF 28N BETWEEN 85W-96W ENHANCED BY UPPER
LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL RIDGE ACROSS THE ERN
CONUS FROM VIRGINIA TO AN UPPER LEVEL HIGH S OF LOUISIANA NEAR
28N92W AND AN UPPER LEVEL TROUGH ACROSS THE CENTRAL CONUS.
SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS THE W FLORIDA COAST N
OF 27N E OF 84W DUE TO UPPER LEVEL DIFFLUENCE BETWEEN THE RIDGE
ACROSS THE NRN GULF/ERN CONUS AND AN UPPER LEVEL TROUGH ACROSS
THE W ATLC. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO ACROSS NW
CUBA FROM 22N-24N BETWEEN 81W-83W INTO THE STRAITS OF
FLORIDA...AND ACROSS THE YUCATAN PENINSULA FROM 18N-21N BETWEEN
88W-91W. THIS ACTIVITY IS ENHANCED BY UPPER LEVEL DIFFLUENCE
BETWEEN THE HIGH IN THE NW GULF AND AN UPPER LEVEL LOW E OF THE
YUCATAN PENINSULA NEAR 19N86W. EXPECT A TROPICAL WAVE ALONG 84W
TO REACH THE YUCATAN PENINSULA TONIGHT AND TO MOVE INTO THE SW
GULF S OF 20N THU.

THE CARIBBEAN SEA...
A TROPICAL WAVE ALONG 84W IS SUPPORTING SCATTERED
SHOWERS/THUNDERSTORMS ACROSS THE SW CARIBBEAN AND CENTRAL
AMERICA FROM 8N-17N BETWEEN 78W-86W. THIS ACTIVITY IS ENHANCED
BY UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL LOW E OF THE
YUCATAN PENINSULA NEAR 19N86W AND AN UPPER LEVEL HIGH OVER
COLUMBIA NEAR 11N74W. A FEW ISOLATED SHOWERS/POSSIBLE
THUNDERSTORMS OVER OVER THE E DOMINICAN REPUBLIC FROM 18N-19N
BETWEEN 69W-70W. THIS ACTIVITY IS MOST LIKELY DUE TO DAYTIME
HEATING AND INSTABILITY...AS THE AREA IN UNDER STRONG SUBSIDENCE
ALOFT. THE REMINDER OF THE CARIBBEAN IS EXPERIENCING GENERALLY
FAIR WEATHER UNDER THE INFLUENCE OF A DRY SAHARAN AIR LAYER AND
STRONG SUBSIDENCE ALOFT. FRESH TO STRONG TRADEWINDS ARE ACROSS
MUCH OF THE BASIN WITH THE HIGHEST WINDS NEAR THE COAST OF
COLUMBIA. LARGE SWELLS ASSOCIATED WITH MAJOR HURRICANE BILL WILL
BEGIN IMPACTING ISLANDS ACROSS THE NE CARIBBEAN IN THE NEXT DAY
OR TWO.

THE ATLANTIC OCEAN...
ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS ARE ACROSS THE FAR W
ATLC N OF 27N W OF 78W. THIS ACTIVITY IS ENHANCED BY UPPER LEVEL
DIFFLUENCE BETWEEN AN UPPER LEVEL RIDGE OVER THE ERN CONUS AND
AN UPPER LEVEL TROUGH ACROSS THE W ATLC WITH AXIS ALONG 72W. A
SURFACE TROUGH ENTERS THE DISCUSSION AREA NEAR 31N42W EXTENDING
TO 29N55W. NO SHOWERS ARE CURRENTLY ASSOCIATED WITH THE TROUGH.
THE REMAINDER OF THE ATLC...BESIDES HURRICANE BILL...SEE
ABOVE...IS DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1021
MB HIGH NEAR 32N71W...AND A 1024 MB HIGH NEAR 32N32W. IN THE
UPPER LEVELS...AN UPPER LEVEL RIDGE IS OVER THE CENTRAL ATLC E
OF THE UPPER TROUGH IN THE W ATLC WITH AN UPPER LEVEL HIGH
CENTERED NEAR 28N31W. AN UPPER LEVEL TROUGH IS ACROSS THE FAR E
ATLC N OF 23N WITH AXIS ALONG 23W.

$$
WALTON

[Gustywind]

Interresting snippet from a correspondant of Stormcarib.com: "Dave"...focusing on a possible tropical system that could appear during the next 10-12 days... Whereas as usual let's be prudent and continue to watch all the suspicious areas between Africa and the Leeser Antilles.
http://www.stormcarib.com/
19 Aug 2009 12:25:21 -0000 - Cat 4 Bill


Good morning!

A slightly ragged Category 4 Hurricane Bill continues his WNW journey towards Bermuda. the New England Coast, and eventually, the Canadian provinces at a decent speed of 16 mph. Fortunately for us here in the Caribbean, Bill has decided to take his impression of a pinwheel elsewhere. Wind shear has taken a slight toll on Bill but that should not last long and Bill could even intensify more as it chugs over warmer sea surface waters. Major beach erosion will be a problem along the northern coast of the US as Bill is pushing upwards of 50 foot waves over the open Atlantic with swells expected to reach the Leeward Islands late today into tomorrow probably necessitating coastal flood and rip current advisories.

Behind Bill, another impressive wave is about to exit the African coast but it will be coming off relatively high, around 15N, so should have no real impact on the Caribbean. Another reason no real impact is Bill has taken much of the moisture out of the air and stolen plenty of heat from the seas so the next system does not have many tools to work with. However, the one behind it might be one worth watching in about 10-12 days or so.

We've dodged another bullet but the Atlantic is sure to keep firing so please stay alert.
For those who have asked, I will not attempt to fly with the hurricane hunters into Bill as I have already been into a Cat 5 named Isabel in 2003. I'm looking for another recurving to the north storm around Cat 1 or 2 status for a better perspective on developing storms.

Dave

[Gustywind]

Good morning to all. Bill is now at 21 of latitud but has weakned a bit, he's a cat 3 cane this morning. Seems that we're fairly out of danger... and in definitive blessed . Moreover, looks like that any feeder bands will affect us. Whereas we should continue to monitor carefully the rough sea, swells in our our area...
Have a nice day all

Say in chorus Good-Bye BILL






000
WTNT33 KNHC 200833
TCPAT3
BULLETIN
HURRICANE BILL ADVISORY NUMBER 20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 AM AST THU AUG 20 2009

...BILL WEAKENS SLIGHTLY TO A CATEGORY THREE HURRICANE...

INTERESTS IN BERMUDA SHOULD MONITOR THE PROGRESS OF BILL. A
HURRICANE OR TROPICAL STORM WATCH WILL LIKELY BE REQUIRED FOR
BERMUDA LATER THIS MORNING.

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 OF THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR NATIONAL METEOROLOGICAL SERVICE.

AT 500 AM AST...0900 UTC...THE CENTER OF HURRICANE BILL WAS LOCATED
NEAR LATITUDE 21.6 NORTH...LONGITUDE 60.3 WEST OR ABOUT 325 MILES...
525 KM...NORTH-NORTHEAST OF THE LEEWARD ISLANDS AND ABOUT 790 MILES
...1270 KM...SOUTH-SOUTHEAST OF BERMUDA.

BILL IS MOVING TOWARD THE NORTHWEST NEAR 18 MPH...30 KM/HR...AND
THIS GENERAL MOTION IS EXPECTED FOR THE NEXT DAY OR SO WITH A TURN
TOWARD THE NORTH-NORTHWEST BY LATE FRIDAY.

MAXIMUM SUSTAINED WINDS HAVE DECREASED TO NEAR 125 MPH...
205 KM/HR...WITH HIGHER GUSTS. BILL IS A CATEGORY THREE HURRICANE
ON THE SAFFIR-SIMPSON SCALE. SOME STRENGTHENING IS POSSIBLE DURING
THE NEXT 24 HOURS...AND BILL COULD REGAIN CATEGORY FOUR STATUS
LATER TODAY OR FRIDAY. A NOAA HURRICANE HUNTER AIRCRAFT IS
CURRENTLY ENROUTE TO INVESTIGATE BILL.

BILL IS A LARGE TROPICAL CYCLONE. HURRICANE FORCE WINDS EXTEND
OUTWARD UP TO 85 MILES...140 KM...FROM THE CENTER...AND TROPICAL
STORM FORCE WINDS EXTEND OUTWARD UP TO 230 MILES...370 KM. DURING
THE PAST SEVERAL HOURS...NOAA BUOY 41044 REPORTED 1-MINUTE MEAN
WINDS OF 77 MPH...124 KM/HR...AND A PEAK GUST OF 92 MPH...
148 KM/HR...AS THE CENTER OF BILL PASSED ABOUT 75 MILES...
120 KM...TO THE SOUTHWEST.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 949 MB...28.02 INCHES.

LARGE SWELLS ASSOCIATED WITH BILL WILL BE IMPACTING THE ISLANDS OF
THE NORTHEAST CARIBBEAN SEA...THE BAHAMAS...AND BERMUDA DURING THE
NEXT DAY OR TWO. LARGE SWELLS ASSOCIATED WITH BILL SHOULD ALSO
BEGIN TO AFFECT PORTIONS OF THE EAST COAST OF THE UNITED STATES
FRIDAY AND SATURDAY.

...SUMMARY OF 500 AM AST INFORMATION...
LOCATION...21.6N 60.3W
MAXIMUM SUSTAINED WINDS...125 MPH
PRESENT MOVEMENT...NORTHWEST OR 305 DEGREES AT 18 MPH
MINIMUM CENTRAL PRESSURE...949 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
1100 AM AST.

$$
FORECASTER BEVEN


000
WTNT43 KNHC 200849
TCDAT3
HURRICANE BILL DISCUSSION NUMBER 20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 AM AST THU AUG 20 2009

DURING THE LAST PASS THROUGH THE NORTHEASTERN EYEWALL...AN AIR
FORCE RESERVE HURRICANE HUNTER AIRCRAFT REPORTED 123 KT WINDS AT
700 MB...WHICH IS DOWN ALMOST 20 KT FROM EARLIER. AN EYEWALL
DROPSONDE SUGGESTS THE SURFACE WINDS IN THAT AREA WERE 105-110 KT.
BASED ON THIS AND A SLIGHT WEAKENING OF THE SATELLITE CLOUD
PATTERN...THE INITIAL INTENSITY IS REDUCED TO 110 KT. ANALYSES
FROM CIMSS AT THE UNIVERSITY OF WISCONSIN SHOW THAT BILL HAS BEEN
EXPERIENCING 10-15 KT OF WESTERLY VERTICAL WIND SHEAR. THIS MAY BE
STARTING TO DIMINISH...AS THE CIRRUS OUTFLOW IS INCREASING IN THE
WESTERN SEMICIRCLE.

THE INITIAL MOTION IS 305/16. BILL IS MOVING TOWARD A WEAKNESS IN
THE SUBTROPICAL RIDGE CAUSED BY TWO MID/UPPER-LEVEL TROUGHS...ONE
TO THE EAST-NORTHEAST OF BERMUDA AND ONE BETWEEN BERMUDA AND THE
UNITED STATES. THE SECOND TROUGH IS FORECAST TO MOVE SOUTHWARD AND
WESTWARD DURING THE NEXT 24-48 HR...CAUSING BILL TO GRADUALLY TURN
MORE NORTHWARD AS THE SYSTEMS INTERACT. AFTER 48 HR...ALL GUIDANCE
FORECASTS A LARGE DEEP-LAYER TROUGH TO MOVE INTO THE EASTERN UNITED
STATES...WITH A LARGE MID/UPPER-LEVEL RIDGE BUILDING OVER THE
CENTRAL ATLANTIC. THIS COMBINATION SHOULD STEER BILL NORTHWARD AND
EVENTUALLY NORTHEASTWARD INTO THE WESTERLIES. THE TRACK GUIDANCE
IS TIGHTLY CLUSTERED FOR THE FIRST 48-72 HR...THEN BECOME SOMEWHAT
DIVERGENT IN BOTH DIRECTION AND SPEED. THE GFDN AND NOGAPS ARE ON
THE LEFT SIDE OF THE GUIDANCE ENVELOPE...BRINGING THE CENTER OF
BILL JUST SOUTHEAST OF NEW ENGLAND AND THEN OVER NOVA SCOTIA AND
NEWFOUNDLAND. THE CORRECTED CONSENSUS MODELS CALL FOR A MUCH
SHARPER EASTWARD TURN...KEEPING THE CENTER WELL AWAY FROM NEW
ENGLAND AND CANADA. THE TRACK FORECAST IS BETWEEN THESE EXTREMES
AND DOWN THE MIDDLE OF THE GUIDANCE ENVELOPE IN BEST OVERALL
AGREEMENT WITH THE GFDL. IT SHOULD BE NOTED THAT BILL WILL
PROBABLY NOT TURN AS SHARPLY BETWEEN 72-96 HR AS IMPLIED BY THE
TRACK GRAPHIC...AND THUS IS LIKELY TO PASS CLOSER TO NEW ENGLAND
THAN THE GRAPHIC WOULD SUGGEST.

THE LARGE-SCALE MODELS SUGGEST THE CURRENT SHEAR SHOULD DIMINISH
DURING THE NEXT 24 HR...AND THIS BASIS SOME RE-INTENSIFICATION IS
EXPECTED. THE INTENSITY FORECAST IS MOST UNCERTAIN DURING THE
24-72 HR TIME FRAME AS BILL INTERACTS WITH THE CURRENT WESTERN
ATLANTIC TROUGH. THIS TROUGH COULD CAUSE SHEAR TO WEAKEN THE
SYSTEM. HOWEVER...SOME OF THE LARGE-SCALE MODELS FORECAST
INCREASED UPPER-LEVEL DIVERGENCE OVER BILL...WHICH COULD STRENGTHEN
THE HURRICANE. FOR NOW...THE INTENSITY FORECAST CALLS FOR LITTLE
CHANGE IN STRENGTH AS A COMPROMISE. AFTER 72 HR...BILL SHOULD
WEAKEN RAPIDLY AS IT MOVES OVER COLDER SEA SURFACE TEMPERATURES AND
INTO STRONG VERTICAL WIND SHEAR. EXTRATROPICAL TRANSITION SHOULD
BEGIN AROUND 96 HR AND BE COMPLETE BY 120 HR.

LARGE SWELLS GENERATED BY THIS HURRICANE WILL AFFECT THE NORTHERN
LEEWARD ISLANDS...THE BAHAMAS...BERMUDA AND MOST OF THE EASTERN
U.S. COAST DURING THE NEXT FEW DAYS. THESE SWELLS WILL LIKELY
CAUSE EXTREMELY DANGEROUS SURF AND LIFE-THREATENING RIP CURRENTS.
PLEASE CONSULT STATEMENTS ISSUED BY YOUR LOCAL WEATHER OFFICE FOR
MORE DETAILS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 20/0900Z 21.6N 60.3W 110 KT
12HR VT 20/1800Z 23.0N 62.3W 115 KT
24HR VT 21/0600Z 25.2N 64.7W 120 KT
36HR VT 21/1800Z 27.8N 66.5W 120 KT
48HR VT 22/0600Z 30.8N 68.1W 120 KT
72HR VT 23/0600Z 38.5N 68.0W 105 KT
96HR VT 24/0600Z 46.6N 59.0W 70 KT
120HR VT 25/0600Z 53.5N 36.0W 55 KT...EXTRATROPICAL

$$
FORECASTER BEVEN

[cycloneye]

Good morning to all.Some scattered showers moving rapidly from NE to SW this morning as Bill moves away from us.The seas will be the biggest problem.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
333 AM AST THU AUG 20 2009

.DISCUSSION...MADE FEW CHANGES TO GOING PACKAGE THIS MORNING AS
SYNOPTIC REASONING SEEMED RIGHT ON TRACK. AS HURRICANE BILL TRACKS
NORTHEAST OF AREA...WINDS ARE TURNING NORTHEASTERLY...BRINGING
SOME FAST MOVING SHOWERS OVER THE ISLANDS AND COASTAL WATERS.
WINDS WILL SHIFT OVER THE NEXT 24 HOURS TO THE NORTH AND SLIGHTLY
NW BEFORE BECOMING SOUTHERLY ON FRIDAY. DURING THAT TIME...LITTLE
CHANGE IN THE SYNOPTIC PATTERN IS EXPECTED...WITH SCATTERED
SHOWERS MOST AREAS AND BRIEF WIND GUSTS. BIGGEST STORY CONTINUES
TO BE WHAT KIND OF SWELL ENERGY THE LOCAL ISLANDS WILL RECEIVE.
BUOY 41044 SHOWED A VERY IMPRESSIVE PASSAGE OF THE MAIN DYNAMIC
FETCH ALONG THE NE QUADRANT OF THE STORM WITH WAVE HEIGHTS OF
NEARLY 40 FEET. 41403...MUCH CLOSER TO OUR LOCAL WATERS IS ALSO
RAPIDLY RISING...AND WILL BE A BIT MORE INDICATIVE OF OUR ATLC
OFFSHORE WATERS. THAT BUOY CURRENTLY SHOWING 10 FEET AT AROUND 12
SECONDS...VERIFYING WNA MODEL INITIALIZATION QUITE WELL. EXPECTING
UP TO 12 FEET IN THE OFFSHORE WATERS. QUESTION WILL BE HOW MUCH
PERIPHERAL SWELL ENERGY FROM THE CYCLONE WILL REACH LOCAL
COASTLINES AND WILL IT BE ENOUGH TO CAUSE LARGE BREAKING WAVES.
ADMITTEDLY...ITS HARD TO GAGE THE IMPACTS OF EASTERLY
SWELL...SINCE ITS NOT THE FAVORABLE DIRECTION FOR BREAKING WAVES.
WITH THIS IN MIND...WILL HOLD OFF ON HIGH SURF ADVISORY FOR
NOW...AND WAIT FOR EVIDENCE OF LARGE BREAKERS LATER TODAY.
REGARDLESS...SEAS WILL BE HEAVY AS SYSTEM MOVES BY.

STILL THINK LARGE SCALE PATTERN WILL BE LARGELY SUBSIDENT...TODAY
WILL BE A MOSTLY SCT SHOWER TYPE DAY...BUT EXPECTING LESS COVERAGE
TONIGHT AND FRIDAY. AS SYSTEM MOVES RAPIDLY UP THE EAST COAST OF
THE STATES THIS WEEKEND SOUTHERLY FLOW IN ITS WAKE WILL DRAG SOME
ITCZ MOISTURE INTO THE LOCAL AREA...ENSURING AT LEAST SCATTERED
COVERAGE. A TUTT LOW IS FORECAST TO FORM MONDAY NORTH OF THE
AREA...WHICH COULD BRING SOME REFLECTING LOWER LEVEL ENERGY AND
SHOWERS TO THE AREA FOR EARLY NEXT WEEK. FURTHER AHEAD INTO NEXT
WEEK LOOKS RELATIVELY THREAT FREE AS FAR AS TROPICAL
CYCLONES...WITH WEAK TO MODERATE WAVE MID TO LATE WEEK.

[Gustywind]

Yellow alert for the rough sea, swells in Guadeloupe and Martinica have been disrupted this morning. Northern Leewards continue to be on yellow alert.
Waves have lessened a bit today in Guadeloupe, Meteo-France expect waves near 2meters with some up to 4 meters, while some weak feeder bands could always reach the butterfly island. We're back in green code meaning no danger in our area.

Given always Meteo-France, the Northern Leewards stay in yellow alert today could see waves near 4 meters and the strongest could reach 6 to 7 meters . Note that the buoy north of PR has mesured yesterday night waves near 4meters yesterday...some waves have reached 6 to 7 meters.

[Gustywind]

000
AWCA82 TJSJ 200926
RWSVI

WEATHER SUMMARY FOR THE U.S. VIRGIN ISLANDS
NATIONAL WEATHER SERVICE SAN JUAN PR
526 AM AST THU AUG 20 2009

PARTLY TO VARIABLY CLOUDY SKIES PREVAILED ACROSS THE U.S. VIRGIN
ISLANDS THIS EARLY THIS MORNING. PASSING SHOWERS MOVED ACROSS THE
ISLANDS AND SURROUNDING WATERS FROM TIME TO TIME TO PRODUCE
PERIODS OF MODERATE RAINFALL. WINDS WERE FROM THE NORTHEAST AT
AROUND 10 MPH WITH HIGHER GUSTS ACCOMPANYING THE PASSING SHOWERS.

SHOWERS WILL CONTINUE TO AFFECT THE LOCAL ISLANDS...GENERATING
PERIODS OF LIGHT TO MODERATE RAINFALL THROUGH MID MORNING.
HOWEVER...NO WIDESPREAD RAINFALL IS EXPECTED. BRIEF GUSTY WINDS
MAY ALSO ACCOMPANY THE PASSING SHOWER AS THEY MOVE ACROSS THE
ISLANDS.

AT 5 AM AST...THE CENTER OF POWERFUL HURRICANE BILL WAS LOCATED
NEAR LATITUDE 21.6 NORTH...LONGITUDE 60.3 WEST OR ABOUT 325
MILES...NORTH NORTHEAST OF THE LEEWARD ISLANDS. THE HURRICANE IS
MOVING TOWARD THE NORTHWEST NEAR 18 MPH. MAXIMUM SUSTAINED WINDS
ARE NEAR 125 MPH...WITH HIGHER GUSTS.

EAST NORTHEAST SWELLS WILL BEGIN TO AFFECT THE LOCAL WATERS THIS
MORNING AND PEAKING TONIGHT. THEREFORE...SMALL CRAFT ADVISORIES WILL
BE IN EFFECT FOR THE ATLANTIC WATERS AND CARIBBEAN PASSAGES. SMALL
CRAFT OPERATORS SHOULD EXERCISE CAUTION ELSEWHERE...EXCEPT FOR THE
WESTERN COASTAL WATERS OF PUERTO RICO.

$$

[Gustywind]

000
ABNT20 KNHC 200531
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT THU AUG 20 2009

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON HURRICANE
BILL...LOCATED ABOUT 315 MILES NORTHEAST OF THE LEEWARD ISLANDS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BEVEN