Tropical Storm Bill | Hurricane Bill – The National Hurricane Center is reporting that a second tropical storm named Bill has formed and that it will quickly become Hurricane Bill.
According to the NHC, Tropical Storm Bill is following hot on the heels of Tropical Storm Ana and is racing toward the Virgin Islands.
Bill is expected to be at least a Category 2 hurricane when it makes landfall in the Virgin Islands and Puerto Rico.
National Hurricane Center on path of Tropical Storm Bill:
TROPICAL DEPRESSION THREE – DISCUSSION NUMBER 1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
1100 AM AST SAT AUG 15 2009SATELLITE IMAGERY AND QUIKSCAT DATA INDICATE THAT THE BROAD AREA OF LOW PRESSURE OVER THE EASTERN ATLANTIC HAS FORMED A WELL-DEFINED CIRCULATION AND SUFFICIENTLY ORGANIZED CONVECTION TO BE DESIGNATED A TROPICAL DEPRESSION.
THE INITIAL INTENSITY IS 30 KT BASED ON THE QUIKSCAT DATA…AS WELL AS SATELLITE INTENSITY ESTIMATES OF 30 AND 35 KT FROM SAB AND TAFB.
THE SYSTEM IS CONSOLIDATING SOUTH OF WHERE THE CENTER WAS BEING TRACKED YESTERDAY…AND THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 265/15.
SOME ERRATIC MOTION IS POSSIBLE TODAY AS THE DEPRESSION INTERACTS WITH THE ELONGATED MONSOON/TROPICAL WAVE CIRCULATION THAT SPAWNED IT.
OVERALL…DEEP-LAYER HIGH PRESSURE OVER THE CENTRAL AND EASTERN ATLANTIC SHOULD STEER THE CYCLONE GENERALLY WESTWARD FOR THE NEXT COUPLE OF DAYS…FOLLOWED BY A TURN TOWARD THE WEST-NORTHWEST.
THE TRACK MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THIS SCENARIO…AND THERE IS A FAIRLY TIGHT CLUSTER OF THE MODELS AROUND THE 5 DAY FORECAST POINT.
ONE EXCEPTION IS THE ECMWF…WHICH FORECASTS SIGNIFICANTLY MORE NORTHWARD MOTION THAN THE OTHER MODELS AND AT THIS TIME IS A RIGHT OUTLIER.
THE CYCLONE IS IN DEEP-LAYER EASTERLY FLOW WITH LIGHT/MODERATE VERTICAL WIND SHEAR FORECAST FOR AT LEAST THE NEXT 4 DAYS.
ALL INTENSITY GUIDANCE FORECASTS THE SYSTEM TO BECOME A HURRICANE BY THE END OF THE FORECAST PERIOD…WITH THE HWRF FORECASTING A MAJOR HURRICANE.
THE INTENSITY FORECAST THUS CALLS FOR GRADUAL STRENGTHENING TO A TROPICAL STORM IN 12 HR AND A HURRICANE IN 72-96 HR IN BEST AGREEMENT WITH THE INTENSITY CONSENSUS MODELS.
FORECAST POSITIONS AND MAX WINDS
INITIAL 15/1500Z 11.5N 34.0W 30 KT
12HR VT 16/0000Z 11.3N 36.1W 35 KT
24HR VT 16/1200Z 11.3N 38.9W 40 KT
36HR VT 17/0000Z 11.8N 41.7W 45 KT
48HR VT 17/1200Z 12.4N 44.4W 50 KT
72HR VT 18/1200Z 14.0N 50.5W 60 KT
96HR VT 19/1200Z 16.5N 57.0W 75 KT
120HR VT 20/1200Z 19.0N 63.0W 90 KT
And that’s the latest news on the rapidly growing threat of Tropical Storm Bill | Hurricane Bill.
Tags: 2009 hurricane season, hurricane bill, hurricane bill path, national hurricane center, tropical storm ana, tropical storm bill, tropical storm bill path
August 15th, 2009 at 5:44 pm
Tropical Storm Bill – Latest Update
TROPICAL STORM BILL DISCUSSION NUMBER 2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 PM AST SAT AUG 15 2009
SATELLITE IMAGERY INDICATES THAT THE DEPRESSION IN THE FAR EASTERN ATLANTIC HAS CONTINUED TO BECOME BETTER ORGANIZED.
THE CYCLONE IS LARGE AND HAS NUMEROUS CYCLONICALLY-CURVED CONVECTIVE BANDS WITH THE OUTFLOW PRIMARILY ON THE WESTERN SEMICIRCLE.
DVORAK T-NUMBERS HAVE INCREASED AND SUPPORT UPGRADING THE SYSTEM TO TROPICAL STORM STATUS WITH AN INITIAL INTENSITY OF 35 KNOTS.
BILL IS EXPECTED TO REMAIN OVER WARM WATERS AND EMBEDDED WITHIN LIGHT SHEAR THROUGH THE FORECAST PERIOD.
STRENGTHENING IS INDICATED AND BILL IS EXPECTED TO BECOME A HURRICANE IN 3 TO 4 DAYS.
THIS IS CONSISTENT WITH THE UPWARD INTENSITY TREND INDICATED BY THE GUIDANCE.
BILL IS IN THE DEEP TROPICS AND IS WELL-EMBEDDED WITHIN THE EASTERLY TRADE WINDS.
THE CYCLONE IS MOVING JUST SOUTH OF DUE WEST OR 265 DEGREES AT 14 KNOTS.
IN GENERAL…NO SIGNIFICANT CHANGE IN THE STEERING CURRENTS IS ANTICIPATED AND BILL SHOULD BEGIN TO TURN A LITTLE MORE TO THE WEST-NORTHWEST AROUND THE PERIPHERY OF THE SUBTROPICAL RIDGE IN A DAY OR SO…WITH LITTLE CHANGE IN FORWARD SPEED.
THERE HAS NOT BEEN A SIGNIFICANT CHANGE IN THE GUIDANCE…AND THE BULK OF THE MODELS HAS BILL AS A HURRICANE JUST NORTH AND VERY NEAR THE NORTHERN LEEWARD ISLANDS AND SO DOES THE OFFICIAL FORECAST.
HURRICANE BILL FORECAST POSITIONS AND MAX WINDS
INITIAL 15/2100Z 11.3N 35.2W 35 KT
12HR VT 16/0600Z 11.2N 37.2W 35 KT
24HR VT 16/1800Z 11.5N 40.0W 45 KT
36HR VT 17/0600Z 12.0N 43.0W 50 KT
48HR VT 17/1800Z 13.0N 46.0W 55 KT
72HR VT 18/1800Z 14.5N 52.0W 60 KT
96HR VT 19/1800Z 17.0N 58.0W 75 KT
120HR VT 20/1800Z 19.5N 63.5W 90 KT
August 15th, 2009 at 10:01 pm
I had no idea a hurricane was on its way behind Ana! Thanks for posting about this.
August 16th, 2009 at 9:08 am
Tropical Storm Bill To Become Major Hurricane
The National Hurricane Center has updated it’s forecast on Tropical Storm Bill to predict an increase to major hurricane strength by Friday.
The prediction that Tropical Storm Bill will become a category 3 hurricane has the Virgin Islands and Puerto Rico preparing for the worst, but the good news is that TS Bill is moving more North than yesterday, so the islands may avoid a direct hit.
TROPICAL STORM BILL DISCUSSION NUMBER 4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 AM AST SUN AUG 16 2009
THE CENTER OF BILL HAS BEEN DIFFICULT TO FIND THIS MORNING…AND A 0419 UTC AMSR-E PASS INDICATED THAT IT HAS EITHER SLOWED DOWN OR HAS BEEN RE-FORMING CLOSER TO THE DEEP CONVECTION.
DVORAK T-NUMBERS ARE NOW 3.0 FROM TAFB AND 2.5 FROM SAB…SO THE INITIAL INTENSITY IS RAISED TO 40 KT.
BILL IS EXPECTED TO GRADUALLY STRENGTHEN OVER THE NEXT COUPLE OF DAYS…AND THE OFFICIAL FORECAST FOLLOWS THE UPWARD TREND NOTED IN THE INTENSITY GUIDANCE.
BILL IS NOW EXPECTED TO REACH MAJOR HURRICANE STATUS BY DAY 5…BUT IT SHOULD BE NOTED THAT THE 100 KT SHOWN IN THE FORECAST IS STILL BELOW THE INTENSITY CONSENSUS AND WELL BELOW THE HWRF MODEL.
THIS IS TO ACCOUNT FOR INCREASED VERTICAL SHEAR THAT MAY DEVELOP BY DAYS 4 AND 5…AS INDICATED IN THE SHIPS GUIDANCE.
THE INITIAL MOTION IS AN UNCERTAIN 270/11. BILL IS EXPECTED TO GRADUALLY GAIN LATITUDE AND TURN TO THE WEST-NORTHWEST OVER THE NEXT FEW DAYS.
THE NEW SUITE OF MODEL GUIDANCE HAS SHIFTED A LITTLE NORTH OF THE PREVIOUS GUIDANCE ENVELOPE AS MOST OF THE MODELS APPEAR TO BE SHOWING THE DEVELOPMENT OF A DEEP MID- TO UPPER-LEVEL TROUGH OVER THE EASTERN UNITED STATES AT THE END OF THE FORECAST PERIOD.
MOST OF THE MODELS…WITH THE EXCEPTION OF THE UKMET AS A SOUTHERN OUTLIER…ARE IN REMARKABLY GOOD AGREEMENT THROUGH DAY 5.
HURRICANE BILL FORECAST POSITIONS AND MAX WINDS
INITIAL 16/0900Z 11.4N 37.2W 40 KT
12HR VT 16/1800Z 11.8N 39.3W 45 KT
24HR VT 17/0600Z 12.5N 41.9W 50 KT
36HR VT 17/1800Z 13.4N 44.7W 60 KT
48HR VT 18/0600Z 14.3N 47.5W 70 KT
72HR VT 19/0600Z 16.5N 53.0W 85 KT
96HR VT 20/0600Z 19.0N 58.5W 95 KT
120HR VT 21/0600Z 22.0N 64.0W 100 KT
August 16th, 2009 at 6:19 pm
Hurricane Bill Could Become Category 4 Storm
TROPICAL STORM BILL DISCUSSION NUMBER 6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 PM AST SUN AUG 16 2009
SATELLITE IMAGES SHOW THAT BILL HAS DEVELOPED A CENTRAL DENSE OVERCAST ALONG WITH IMPRESSIVE BANDING AND OUTFLOW. THESE FEATURES SUGGEST THAT THE STORM CONTINUES TO INTENSIFY.
SATELLITE INTENSITY ESTIMATES FROM TAFB/SAB HAVE INCREASED TO T3.5…55 KT ON THE DVORAK SCALE AND THIS VALUE WILL BE USED FOR THE INITIAL WIND SPEED.
BILL IS MOVING TOWARD THE WEST-NORTHWEST OR 285/14. THIS GENERAL MOTION IS EXPECTED FOR THE NEXT COUPLE OF DAYS AS A SUBTROPICAL RIDGE SHOULD REMAIN FIRM TO THE NORTH OF THE TROPICAL CYCLONE.
THEREAFTER…A COUPLE OF EVOLUTIONS TO THE SYNOPTIC PATTERN SEEM POSSIBLE. THE FIRST…FAVORED BY THE GFS/ECMWF/GFDL/HWRF…SHOWS A MID-LATITUDE SHORTWAVE DIVING INTO THE SUBTROPICAL RIDGE…CAUSING IT TO BREAK AROUND 65W.
THIS LEADS TO A NORTHWEST MOTION OF BILL IN ABOUT THREE DAYS.
THE OTHER SOLUTION…SHOWN BY THE NOGAPS/UKMET…IS THAT THE HURRICANE BYPASSES THE FIRST BREAK AND CONTINUES MOVING TOWARD THE WEST-NORTHWEST…EVENTUALLY TURNING NORTHWEST AT THE END OF THE FORECAST DUE TO A LARGE MID-LATITUDE TROUGH APPROACHING THE EASTERN UNITED STATES.
THE OFFICIAL FORECAST IS SHIFTED A LITTLE BIT TO THE RIGHT AT THE END…IN DEFERENCE TO THE HIGHLY-SKILLED MODELS IN THE FORMER SOLUTION.
WATER VAPOR IMAGES SHOW THAT THE HURRICANE IS ON THE SOUTH SIDE OF AN UPPER HIGH WITH LITTLE SHEAR LIKELY FOR THE NEXT SEVERAL DAYS.
IN COMBINATION WITH WARM SSTS…THERE IS NO REASON NOT TO FORECAST CONTINUED STRENGTHENING OF BILL.
IN FACT…THE SHIPS RAPID INTENSIFICATION INDEX SHOWS A 38 PERCENT CHANCE OF A 30 KT INCREASE IN WINDS DURING THE NEXT 24 HOURS.
ALL RELIABLE MODELS CONTINUE TO SHOW THIS SYSTEM BECOMING A MAJOR HURRICANE…WITH THE GFDL/HWRF/GFDN MODELS FORECASTING BILL TO REACH CATEGORY FOUR STRENGTH BY DAY 5.
HOWEVER…THERE IS SOME EVIDENCE IN THE GLOBAL MODEL FIELDS THAT THE UPPER-LEVEL WINDS WILL BECOME LESS FAVORABLE AFTER 72 HOURS WITH SOME SOUTHWESTERLY SHEAR DEVELOPING AS BILL BECOMES DISPLACED FROM AN UPPER-LEVEL HIGH.
THE OFFICIAL FORECAST WILL SHOW THE INTENSITY LEVELING OFF AFTER THAT TIME DUE TO THAT POSSIBILITY.
THE NHC INTENSITY FORECAST IS CLOSE TO THE PREVIOUS FORECAST AND IS SIMILAR TO THE SHIPS MODEL.
HURRICANE BILL FORECAST POSITIONS AND MAX WINDS
INITIAL 16/2100Z 12.8N 40.0W 55 KT
12HR VT 17/0600Z 13.4N 42.1W 65 KT
24HR VT 17/1800Z 14.2N 45.0W 75 KT
36HR VT 18/0600Z 15.0N 47.7W 85 KT
48HR VT 18/1800Z 16.0N 50.4W 95 KT
72HR VT 19/1800Z 18.5N 55.5W 105 KT
96HR VT 20/1800Z 22.0N 60.5W 105 KT
120HR VT 21/1800Z 26.5N 65.0W 105 KT
August 16th, 2009 at 7:33 pm
will hurricane bill hit panhandle of florida?
August 17th, 2009 at 8:17 am
Hurricane Bill Strengthening Rapidly
The National Hurricane Center is predicting that Hurricane Bill could intensify rapidly in favorable conditions and increase wind speed by 30 knots in one day.
The NHC forecast places Bill as a Category 3 hurricane by Wednesday and a Category 4 hurricane by Thursday.
Bill is moving fast at 19 knots, but forecasters are placing Bill’s projected path further northward than before, which is good news for the Virgin Islands and Puerto Rico, but bad news for Bermuda.
HURRICANE BILL DISCUSSION NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 AM AST MON AUG 17 2009
INFRARED SATELLITE PICTURES REVEAL AN IMPRESSIVE MASS OF DEEP CONVECTION…WITH A LARGE AREA OF -70C AND EVEN -80C CLOUD TOPS WITHIN A WELL-ORGANIZED CENTRAL DENSE OVERCAST.
IN ADDITION…SEVERAL WELL-DEFINED BANDS ARE NOTED OUTSIDE OF THE CENTRAL CONVECTIVE CORE.
A 0142 UTC TRMM PASS INDICATED A DISTINCT CONVECTIVE RING AROUND THE CENTER…ALSO SUGGESTIVE OF INCREASED ORGANIZATION.
DVORAK T-NUMBERS ARE AT 4.0 FROM TAFB AND SAB…ALONG WITH CURRENT TRENDS…SUPPORT INCREASING THE INITIAL INTENSITY TO 65 KT.
THIS MAKES BILL THE FIRST HURRICANE OF THE 2009 ATLANTIC HURRICANE SEASON.
RECENT SATELLITE CENTER FIXES ARE LESS DOUBTFUL THAN EARLIER AND YIELD A RATHER RAPID INITIAL MOTION ESTIMATE OF 285/19.
GLOBAL MODELS ARE IN GOOD AGREEMENT ON A GENERAL WEST-NORTHWEST TRACK FOR THE NEXT DAY OR TWO…AS BILL IS STEERED BY A DEEP-LAYER RIDGE NORTHEAST OF THE CYCLONE.
HOWEVER…WATER VAPOR IMAGERY SHOWS A WEAKNESS CURRENTLY ALONG 50W…WHICH IS FORECAST TO BEGIN ERODING A PORTION OF THE SUBTROPICAL RIDGE OVER THE CENTRAL ATLANTIC OVER THE NEXT 48 HOURS.
AS THE BREAK IN THE RIDGE BECOMES MORE SUBSTANTIAL…A MAJORITY OF THE MODEL GUIDANCE TURNS BILL ON A MORE NORTHWESTWARD COURSE LATE IN THE FORECAST PERIOD.
THE ONE EXCEPTION IS THE UKMET WHICH INSISTS ON A MORE SOUTHERN SOLUTION.
THE OFFICIAL TRACK IS INITIALLY NUDGED SLIGHTLY SOUTHWARD IN THE SHORT-TERM TO ACCOUNT FOR A MORE CERTAIN INITIAL POSITION…BUT LITTLE CHANGE WAS MADE TO THE PREVIOUS TRACK THEREAFTER.
BILL IS EXPECTED TO TRACK THROUGH AN ENVIRONMENT CHARACTERIZED BY LOW SHEAR AND SEA SURFACE TEMPERATURES JUST UNDER 27C THROUGH 24 HOURS.
SIMILAR TO BEFORE…THE GFDL/HWRF INDICATE A NEARLY FLAT RATE OF INTENSIFICATION FOR THE NEXT DAY OR TWO…PERHAPS REFLECTING MARGINALLY WARM WATERS.
IN SPITE OF THIS…THE SHIPS RAPID INTENSIFICATION INDEX HAS CONTINUED FORECASTING A RATHER HIGH PROBABILITY OF A 30 KT INTENSITY INCREASE DURING THE NEXT 24 HOURS.
THEREAFTER…ALL INTENSITY GUIDANCE INDICATES A CONDUCIVE ENVIRONMENT FOR STRENGTHENING…WHICH SHOULD ALLOW BILL TO BECOME A MAJOR HURRICANE.
THE OFFICIAL FORECAST FOLLOWS SUIT…CLOSEST TO THE SHIPS MODEL GUIDANCE.
TOWARD THE END OF THE FORECAST PERIOD…SEVERAL OF THE RELIABLE GLOBAL MODELS SUGGEST INCREASING WESTERLY SHEAR AS BILL IS SEPARATED FROM ITS FAVORABLE…UPPER-LEVEL SUPPORT.
CONSEQUENTLY…THE OFFICIAL INTENSITY FORECAST INDICATES MINOR WEAKENING NEAR THE END OF THE PERIOD.
IT APPEARS AS IF THE CENTER OF BILL WILL PASS VERY CLOSE TO NOAA BUOY 41041 LATER THIS MORNING.
HURRICANE BILL PROJECTED PATH:
FORECAST POSITIONS AND MAX WINDS
INITIAL 17/0900Z 13.8N 44.0W 65 KT
12HR VT 17/1800Z 14.4N 46.4W 75 KT
24HR VT 18/0600Z 15.1N 49.0W 85 KT
36HR VT 18/1800Z 16.0N 51.6W 95 KT
48HR VT 19/0600Z 17.3N 54.0W 105 KT
72HR VT 20/0600Z 20.5N 59.0W 110 KT
96HR VT 21/0600Z 25.0N 63.5W 105 KT
120HR VT 22/0600Z 30.1N 66.5W 100 KT
August 17th, 2009 at 1:40 pm
Thank you for your updates. I’ve lived in Florida for 6 years now and I always get really stressed during hurricane season.
August 17th, 2009 at 6:00 pm
Projected Path of Hurricane Bill – Latest Update
Category 3 storm Bill still headed sliightly south and west of Bermuda.
HURRICANE BILL DISCUSSION NUMBER 10…CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 PM AST MON AUG 17 2009
CORRECTED BUOY ID TO 41041
BILL IS BEGINNING TO SHOW SIGNS OF DEVELOPING INNER CORE FEATURES…WITH HINTS OF AN EYE FORMING IN RECENT SATELLITE IMAGERY AND EXPANDING COLD CLOUD TOPS AROUND THE CENTER.
DVORAK T-NUMBERS WERE 4.5 FROM SAB AND TAFB AT 1800 UTC…AND THE INITIAL INTENSITY IS HELD AT 80 KT FOR THIS PACKAGE.
BILL PASSED JUST TO THE NORTH OF NOAA BUOY 41041 THIS AFTERNOON…WHICH REPORTED A MINIMUM PRESSURE OF 972 MB AT 1800 UTC WITH A PEAK 1-MINUTE WIND OF 51 KT.
BASED ON THESE DATA…THE CENTRAL PRESSURE ESTIMATE IS REDUCED TO 969 MB.
THE INTENSITY FORECAST IS UNCHANGED FROM THE PREVIOUS PACKAGE. THE ENVIRONMENT AROUND THE CYCLONE APPEARS FAVORABLE FOR INTENSIFICATION.
OCEAN TEMPERATURES INCREASE ALONG THE TRACK…AND THE GFS AND ECMWF BOTH SHOW AN UPPER-LEVEL ANTICYCLONE DEVELOPING OVER THE SYSTEM.
AS WAS THE CASE EARLIER…THE SHIPS AND LGEM SHOW A BROAD PEAK IN INTENSITY IN 2 OR 3 DAYS…WHILE THE HWRF AND GFDL SHOW ARE STRONGER LATER IN THE PERIOD.
THE OFFICIAL FORECAST REMAINS UNCHANGED FROM THE PREVIOUS ADVISORY…PEAKING A LITTLE HIGHER THAN THE SHIPS AND LGEM BEFORE SHOWING SOME WEAKENING AT DAY 5.
THE INITIAL MOTION ESTIMATE IS 285/14.
THE TRACK MODEL GUIDANCE IS IN EXCELLENT AGREEMENT THROUGH 48 HOURS…AND THROUGH THAT TIME THE OFFICIAL FORECAST IS SIMPLY AN EXTENSION OF THE PREVIOUS PACKAGE.
BEYOND THAT TIME ALMOST ALL OF THE TRACK GUIDANCE HAS SHIFTED TO THE LEFT….WITH THE EXCEPTION OF THE UKMET…WHICH HAS FINALLY TRENDED TOWARD A RECURVATURE SCENARIO.
ALL OF THE GLOBAL MODELS NOW SHOW BILL INTERACTING WITH A LARGE MID TO UPPER-LEVEL TROUGH CENTERED OVER THE EASTERN UNITED STATES BY THE END OF THE PERIOD…HOWEVER THERE ARE DIFFERENCES IN THE AMPLITUDE AND SPEED OF THE TROUGH THAT WILL BE CRUCIAL TO WHEN AND WHERE BILL RECURVES.
INTERESTINGLY…THE GFS AND ECMWF ARE IN EXCELLENT AGREEMENT AT 5 DAYS…BUT NOW LIE ON THE EASTERN EDGE OF THE GUIDANCE ENVELOPE…WITH THE GFS ENSEMBLE MEAN EVEN FARTHER EAST.
GIVEN THE SPREAD IN THE GUIDANCE…THE OFFICIAL FORECAST IS SHIFTED ONLY SLIGHTLY TO THE LEFT OF THE PREVIOUS PACKAGE AT DAYS 3 THROUGH 5…AND LIES BETWEEN THE TVCN MULTI-MODEL CONSENSUS AND THE ECMWF/GFS BLEND.
THIS IS A GOOD TIME TO EMPHASIZE THE UNCERTAINTY THAT EXISTS IN TRACK FORECASTING IN THE 3 TO 5 DAY PERIOD…WHERE AVERAGE NHC TRACK ERRORS ARE TYPICALLY SEVERAL HUNDRED MILES.
HURRICANE BILL FORECAST POSITIONS AND MAX WINDS
INITIAL 17/2100Z 14.6N 46.7W 80 KT
12HR VT 18/0600Z 15.2N 48.7W 90 KT
24HR VT 18/1800Z 16.2N 51.3W 95 KT
36HR VT 19/0600Z 17.4N 53.8W 100 KT
48HR VT 19/1800Z 18.8N 56.4W 105 KT
72HR VT 20/1800Z 22.5N 61.0W 110 KT
96HR VT 21/1800Z 27.0N 65.0W 110 KT
120HR VT 22/1800Z 33.1N 67.5W 105 KT
August 18th, 2009 at 5:43 am
Very good information for one to exrcise his or her interest in something that is important
August 18th, 2009 at 8:38 am
Hurricane Bill Now Category 2 Storm
HURRICANE BILL DISCUSSION NUMBER 12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 AM AST TUE AUG 18 2009
AT 500 AM AST…0900 UTC…THE CENTER OF HURRICANE BILL WAS LOCATED NEAR LATITUDE 15.5 NORTH…LONGITUDE 49.7 WEST OR ABOUT 810 MILES…1305 KM…EAST OF THE LEEWARD ISLANDS.
BILL IS MOVING TOWARD THE WEST-NORTHWEST NEAR 17 MPH…28 KM/HR…AND THIS MOTION IS EXPECTED TO CONTINUE FOR THE NEXT DAY OR TWO WITH A GRADUAL TURN TO THE NORTHWEST ON WEDNESDAY.
MAXIMUM SUSTAINED WINDS ARE NEAR 100 MPH…160 KM/HR…WITH HIGHER GUSTS.
HURRICANE BILL IS A CATEGORY TWO HURRICANE ON THE SAFFIR-SIMPSON SCALE. STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS…AND BILL COULD BECOME A MAJOR HURRICANE WITHIN THE NEXT DAY OR SO.
HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 30 MILES…45 KM…FROM THE CENTER…AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 150 MILES…240 KM.
ESTIMATED MINIMUM CENTRAL PRESSURE IS 967 MB…28.56 INCHES.
TRMM DATA FROM 0223 UTC AND RECENT INFRARED IMAGERY SUGGEST THAT BILL IS UNDERGOING AN EYEWALL REPLACEMENT CYCLE…WITH THE COLDEST CLOUD TOPS CURRENTLY IN THE OUTER CONVECTIVE RING.
SATELLITE INTENSITY ESTIMATES REMAIN 90 KT FROM SAB AND 77 KT FROM TAFB.
THE INITIAL INTENSITY IS 85 KT…AND THIS COULD BE GENEROUS DUE TO THE EYEWALL REPLACEMENT.
THE INITIAL MOTION IS 285/15.
HURRICANE BILL IS ON THE SOUTH SIDE OF A LOW/MID-LEVEL RIDGE…WHICH SHOULD STEER THE HURRICANE GENERALLY WEST-NORTHWESTWARD FOR THE NEXT COUPLE OF DAYS.
AFTER THAT…THE LARGE-SCALE MODELS FORECAST THE RIDGE TO WEAKEN AS A SERIES OF TROUGHS MOVE THROUGH THE WESTERN ATLANTIC AND THE EASTERN UNITED STATES.
ONE MID/UPPER-LEVEL TROUGH IS CURRENTLY NORTHEAST OF BERMUDA…MOVING SOUTHWARD.
A SECOND MID/UPPER-LEVEL TROUGH IS ALONG THE EAST COAST OF THE UNITED STATES…FORECAST TO MOVE EASTWARD AND THEN SOUTHWARD.
FINALLY…A STRONG DEEP-LAYER TROUGH IS FORECAST TO DEVELOP OVER THE EASTERN UNITED STATES BETWEEN 72-120 HR.
ALL TRACK GUIDANCE INDICATES THAT BILL SHOULD TURN NORTHWARD IN RESPONSE TO THE TROUGHS…BUT THERE IS SOME NOTABLE SPREAD IN WHERE AND WHEN.
THE ECMWF…GFS…GFS ENSEMBLE MEAN…AND THE BAM MODELS TURN BILL NORTHWARD BETWEEN 62W-65W IN RESPONSE TO THE FIRST TWO TROUGHS.
THE REMAINDER OF THE TRACK GUIDANCE CALLS FOR THE NORTHWARD TURN BETWEEN 65W-70W…DUE TO LESS RESPONSE TO THE FIRST TWO TROUGHS AND THE EVENTUAL EFFECT OF THE THIRD TROUGH.
THE PREVIOUS FORECAST TRACK WAS IN THE WESTERN CLUSTER…AND THERE IS NO OBVIOUS REASON TO JUMP THE FORECAST TO THE EASTERN CLUSTER.
THEREFORE…THE NEW TRACK IS DOWN THE MIDDLE OF THE WESTERN GUIDANCE CLUSTER AND SIMILAR TO THE PREVIOUS FORECAST.
BILL IS IN A LIGHT VERTICAL WIND SHEAR ENVIRONMENT…AND THE SEA SURFACE TEMPERATURES INCREASE ALONG THE FORECAST TRACK.
THE HURRICANE SHOULD INTENSIFY AFTER THE EYEWALL REPLACEMENT CYCLE IS OVER…WITH ALL GUIDANCE FORECASTING IT TO BECOME A MAJOR HURRICANE.
THE INTENSITY FORECAST CALLS FOR A PEAK INTENSITY OF 110 KT IN 48 HR.
AFTER 48 HR…THE LARGE-SCALE MODELS FORECAST BILL TO ENCOUNTER MODERATE SOUTHERLY OR SOUTHWESTERLY VERTICAL WIND SHEAR…AND THE INTENSITY FORECAST THUS CALLS FOR GRADUAL WEAKENING DURING THAT TIME.
HURRICANE BILL FORECAST POSITIONS AND MAX WINDS
INITIAL 18/0900Z 15.5N 49.7W 85 KT
12HR VT 18/1800Z 16.2N 51.7W 90 KT
24HR VT 19/0600Z 17.4N 54.2W 100 KT
36HR VT 19/1800Z 18.9N 56.7W 105 KT
48HR VT 20/0600Z 20.5N 59.0W 110 KT
72HR VT 21/0600Z 24.0N 63.5W 110 KT
96HR VT 22/0600Z 29.5N 67.5W 105 KT
120HR VT 23/0600Z 35.5N 68.0W 100 KT
August 18th, 2009 at 7:43 pm
Hurricane Bill Becomes Major Hurricane
HURRICANE BILL DISCUSSION NUMBER 14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 PM AST TUE AUG 18 2009
BILL REMAINS A VERY IMPRESSIVE AND SYMMETRIC HURRICANE IN SATELLITE IMAGERY.
MAXIMUM SUSTAINED WINDS ARE NEAR 110 MPH…175 KM/HR…WITH HIGHER GUSTS.
BILL IS A CATEGORY TWO HURRICANE ON THE SAFFIR-SIMPSON SCALE.
STRENGTHENING IS FORECAST DURING THE NEXT DAY OR TWO AND BILL IS EXPECTED TO BECOME A MAJOR HURRICANE TONIGHT OR WEDNESDAY.
HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 45 MILES…75 KM…FROM THE CENTER…AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 175 MILES…280 KM.
THE MINIMUM CENTRAL PRESSURE REPORTED BY RECONNAISSANCE AIRCRAFT WAS 962 MB…28.41 INCHES.
THE AIR FORCE HURRICANE HUNTER AIRCRAFT INVESTIGATING BILL THIS AFTERNOON REPORTED PEAK 700 MB FLIGHT-LEVEL WINDS OF 114 KT IN THE NORTHEAST QUADRANT.
THE SFMR OBSERVED MAXIMUM WINDS AROUND 85 KT IN EACH QUADRANT OF THE HURRICANE.
USING A BLEND OF THESE DATA…THE INITIAL INTENSITY HAS BEEN INCREASED TO 95 KT.
THIS IS ALSO SUPPORTED BY SUBJECTIVE DVORAK INTENSITY ESTIMATES OF 90 AND 102 KT FROM SAB AND TAFB RESPECTIVELY.
THE INITIAL MOTION IS 290/14.
THE FORECAST SCENARIO REMAINS UNCHANGED FROM THE PREVIOUS ADVISORY.
BILL IS EXPECTED TO GRADUALLY TURN TO THE NORTHWEST DURING THE NEXT DAY OR TWO AS A WEAKNESS DEVELOPS IN THE SUBTROPICAL RIDGE OVER THE WESTERN ATLANTIC.
THEREAFTER…THE HURRICANE IS FORECAST TO TURN NORTHWARD AHEAD OF A STRONG TROUGH MOVING INTO THE EASTERN UNITED STATES.
THE TRACK GUIDANCE ENVELOPE CHANGED VERY LITTLE THROUGH 48 HOURS…BUT HAS GENERALLY SHIFTED WESTWARD DURING THE REMAINDER OF THE FORECAST PERIOD.
AS BEFORE THE ECMWF AND GFS ARE ON THE RIGHT SIDE OF THE ENVELOPE WHILE THE UKMET IS ON THE LEFT.
THE OFFICIAL FORECAST IS VIRTUALLY UNCHANGED THROUGH DAY 2…AND HAS NOT BEEN ADJUSTED APPRECIABLY BEYOND THAT TIME AS WELL.
THE NEW FORECAST LIES BETWEEN THE DYNAMICAL MODEL CONSENSUS AND THE USUALLY WELL-PERFORMING ECMWF AND GFS MODELS.
VERTICAL WIND SHEAR IS EXPECTED TO REMAIN LOW AND SSTS GRADUALLY INCREASE ALONG THE FORECAST TRACK DURING THE NEXT COUPLE OF DAYS.
THE INTENSITY FORECAST CALLS FOR ADDITIONAL STRENGTHENING DURING THE NEXT COUPLE OF DAYS IN LINE WITH THE CONSENSUS OF THE INTENSITY GUIDANCE.
BEYOND 72 HOURS…DECREASING SSTS AND INCREASING SOUTHWESTERLY UPPER-LEVEL WINDS AHEAD OF THE AFOREMENTIONED TROUGH SHOULD INDUCE SLOW WEAKENING.
HURRICANE BILL FORECAST POSITIONS AND MAX WINDS
INITIAL 18/2100Z 16.6N 52.2W 95 KT
12HR VT 19/0600Z 17.5N 54.3W 105 KT
24HR VT 19/1800Z 18.9N 56.9W 115 KT
36HR VT 20/0600Z 20.7N 59.3W 115 KT
48HR VT 20/1800Z 22.6N 61.8W 115 KT
72HR VT 21/1800Z 27.3N 65.8W 110 KT
96HR VT 22/1800Z 33.5N 68.0W 100 KT
120HR VT 23/1800Z 40.5N 65.5W 85 KT
August 19th, 2009 at 8:12 am
Hurricane Bill Now Category 4 – Projected Path Could Threaten New England
Powerful Hurricane Bill has 125 mph winds that extend 45 miles outward from its center and the huge tropical storm system spans 350 miles across as it skirts the northern Leeward Isands.
Bill’s projected path shifts further westward each day and some computer models now show a storm track that skirts the New England coast.
HURRICANE BILL DISCUSSION NUMBER 16
NWS TPC / NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 AM AST WED AUG 19 2009
BILL HAS A WELL-DEFINED 25-30 N MI WIDE EYE WITH EYEWALL CLOUD TOPS TO NEAR -80C. SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB WERE 115 KT AT 06Z…AND THE CURRENT SATELLITE SIGNATURE SUGGESTS A SLIGHTLY STRONGER SYSTEM.
BASED ON THE SATELLITE ESTIMATES…THE INITIAL INTENSITY IS INCREASED TO 115 KT. A NOAA HURRICANE HUNTER AIRCRAFT IS CURRENTLY ENROUTE TO INVESTIGATE BILL.
BILL IS MOVING TOWARD THE WEST-NORTHWEST NEAR 16 MPH…26 KM/HR…AND A GRADUAL TURN TOWARD THE NORTHWEST IS EXPECTED DURING THE NEXT 24 TO 48 HOURS.
ON THIS TRACK…THE CORE OF THIS DANGEROUS HURRICANE WILL BE PASSING WELL TO THE NORTHEAST OF THE NORTHERN LEEWARD ISLANDS LATE TODAY AND EARLY THURSDAY.
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 FORECAST DURING THE NEXT 24 HOURS.
HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 45 MILES…75 KM…FROM THE CENTER…AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 175 MILES…280 KM.
THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 948 MB…27.99 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 SOUTHEASTERN COAST OF THE UNITED STATES FRIDAY AND SATURDAY.
THE MOTION IS WOBBLING BETWEEN 295-300 DEGREES AT 14 KT.
BILL IS ON THE SOUTHWEST SIDE OF THE ATLANTIC SUBTROPICAL RIDGE.
WATER VAPOR IMAGERY SHOWS A MID/UPPER-LEVEL LOW NEAR 32N60W AND A MID/UPPER-LEVEL TROUGH N OF 30N BETWEEN 69W-75W.
THESE FEATURES ARE CURRENTLY CREATING A WEAKNESS IN THE WESTERN PORTION OF THE SUBTROPICAL RIDGE.
THE TRACK GUIDANCE MODELS FORECAST BILL TO GRADUALLY TURN NORTHWESTWARD TOWARDS THIS WEAKNESS DURING THE NEXT 48-72 HR…WITH THE ECMWF SHOWING THE EARLIEST TURN AND THE NOGAPS/UKMET SHOWING THE LATEST TURN.
AFTER THAT…A LARGE DEEP-LAYER TROUGH MOVING INTO THE EASTERN UNITED STATES SHOULD CAUSE BILL TO RECURVE NORTHWARD AND NORTHEASTWARD.
THERE IS A LARGE MODEL SPREAD IN BOTH DIRECTION AND SPEED AFTER 72 HR…WITH THE NOGAPS ON ONE SIDE BRINGING BILL NEAR NEW ENGLAND AND THE CORRECTED CONSENSUS MODELS ON THE OTHER SIDE CALLING FOR A SHARP TURN OUT TO SEA.
OVERALL…THE ENVELOPE OF MODEL GUIDANCE HAS SHIFTED A LITTLE TO THE WEST…SO THE NEW OFFICIAL FORECAST WILL DO LIKEWISE.
THE NEW FORECAST TRACK IS NEAR THE MODEL CONSENSUS AND THE MIDDLE OF THE GUIDANCE ENVELOPE.
BILL HAS STRENGTHENED IN SPITE OF BEING IN AN ENVIRONMENT OF 10-15 KT OF SOUTHWESTERLY VERTICAL WIND SHEAR.
THE LARGE-SCALE MODELS FORECAST THIS SHEAR SHOULD DECREASE AFTER 12 HR…SO ADDITIONAL STRENGTHENING IS FORECAST.
BY 48-72 HR…BILL SHOULD INTERACT WITH THE UPPER-LEVEL TROUGH CURRENTLY JUST OFF THE NORTH CAROLINA COAST.
THIS IS LIKELY TO CAUSE ANOTHER ROUND OF SHEAR…SO THE INTENSITY FORECAST CALLS FOR SLOW WEAKENING DURING THAT TIME.
AFTER 72 HR…BILL SHOULD BECOME EMBEDDED IN THE WESTERLIES AS IT MOVES OVER COLDER SEA SURFACE TEMPERATURES…AND A FASTER WEAKENING IS EXPECTED.
IT SHOULD BE NOTED THAT EYEWALL REPLACEMENT CYCLES…WHICH ARE VERY DIFFICULT TO ANTICIPATE…MAY PRODUCE SOME FLUCTUATIONS IN INTENSITY SUPERIMPOSED ON THE GENERAL TREND OF THE INTENSITY FORECAST.
HURRICANE BILL FORECAST POSITIONS AND MAX WINDS
INITIAL 19/0900Z 18.0N 54.9W 115 KT
12HR VT 19/1800Z 19.0N 56.8W 120 KT
24HR VT 20/0600Z 20.6N 59.4W 125 KT
36HR VT 20/1800Z 22.5N 62.0W 125 KT
48HR VT 21/0600Z 24.4N 64.4W 120 KT
72HR VT 22/0600Z 29.5N 68.0W 115 KT
96HR VT 23/0600Z 36.0N 68.5W 100 KT
120HR VT 24/0600Z 44.0N 62.0W 80 KT
August 19th, 2009 at 6:13 pm
Hurricane Bill Projected Path – Latest Update
It’s looking more and more likely that Hurricane Bill could threaten the New England area with high winds and heavy rain as the projected path of Hurricane Bill has shifted further westward, as it has with every update from the National Hurricane Center.
Here’s the latest update:
HURRICANE BILL DISCUSSION NUMBER 18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 PM AST WED AUG 19 2009
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.
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.
HURRICANE BILL 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
August 20th, 2009 at 7:15 am
Hurricane Bill Path – Latest Update – August 19, 2009
Hurricane Bill to hammer New England coast with high winds, heavy rain, and rough surf on Sunday.
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
August 20th, 2009 at 11:27 am
Hurricane Bill Sending Large Waves Ashore All Along The Eastern Seaboard
The National Hurricane Service is warning of dangerously large waves and life-threatening rip currents all along the Eastern Seaboard of the United States as the massive 525-wide storm known as Hurricane Bill slowly churns northeastward through the Atlantic Ocean.
The large swells will be pounding the coastline from Florida to Maine through Sunday night with storm surges and flooding likely in low-lying areas.
Here’s the latest update:
HURRICANE BILL ADVISORY NUMBER 21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
1100 AM AST THU AUG 20 2009
…LARGE HURRICANE BILL SPREADING HIGH SWELLS OVER THE WESTERN ATLANTIC…
AT 11 AM AST…1500 UTC…THE BERMUDA WEATHER SERVICE HAS ISSUED A HURRICANE WATCH FOR BERMUDA. A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA…GENERALLY WITHIN 36 HOURS.
AT 1100 AM AST…1500 UTC…THE EYE OF HURRICANE BILL WAS LOCATED NEAR LATITUDE 22.6 NORTH…LONGITUDE 61.7 WEST OR ABOUT 380 MILES…610 KM…NORTH OF THE LEEWARD ISLANDS AND ABOUT 695 MILES…1120 KM…SOUTH-SOUTHEAST OF BERMUDA.
BILL IS MOVING TOWARD THE NORTHWEST NEAR 18 MPH…30 KM/HR…AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE TROUGH FRIDAY.
ON THIS FORECAST TRACK…THE CORE OF HURRICANE BILL IS EXPECTED TO PASS OVER OPEN WATERS BETWEEN BERMUDA AND THE EAST COAST OF THE UNITED STATES EARLY SATURDAY.
MAXIMUM SUSTAINED WINDS HAVE DECREASED TO NEAR 120 MPH…195 KM/HR…WITH HIGHER GUSTS.
BILL IS A CATEGORY THREE HURRICANE ON THE SAFFIR-SIMPSON SCALE.
SOME STRENGTHENING IS FORECAST DURING THE NEXT 24 HOURS AND BILL COULD REGAIN CATEGORY FOUR STATUS ON FRIDAY.
BILL IS A LARGE TROPICAL CYCLONE. HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 105 MILES…165 KM…FROM THE CENTER…AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 260 MILES…415 KM.
THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY A NOAA P-3 HURRICANE RECONNAISSANCE AIRCRAFT WAS 951 MB…28.08 INCHES.
LARGE SWELLS GENERATED BY THIS HURRICANE ARE AFFECTING THE NORTHERN LEEWARD ISLANDS AND SHOULD BEGIN AFFECTING THE BAHAMAS…BERMUDA…MOST OF THE EASTERN U.S. COAST…AND THE ATLANTIC MARITIMES OF CANADA DURING THE NEXT FEW DAYS.
THESE SWELLS WILL LIKELY CAUSE EXTREMELY DANGEROUS SURF AND LIFE-THREATENING RIP CURRENTS.
…SUMMARY OF 1100 AM AST INFORMATION…
LOCATION…22.6N 61.7W
MAXIMUM SUSTAINED WINDS…120 MPH
PRESENT MOVEMENT…NORTHWEST OR 305 DEGREES AT 18 MPH
MINIMUM CENTRAL PRESSURE…951 MB
August 21st, 2009 at 10:46 am
HURRICANE BILL DISCUSSION NUMBER 25
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
1100 AM AST FRI AUG 21 2009
AFTER SOME DETERIORATION OF THE CLOUD PATTERN EARLY THIS MORNING…VISIBLE SATELLITE IMAGES INDICATE THAT THE EYE HAS BECOME APPARENT AGAIN ALTHOUGH IS NOT AS DISTINCT IT WAS YESTERDAY.
MICROWAVE IMAGES SHOW A CONVECTIVE RING ASSOCIATED WITH THE EYEWALL WITH AN OUTER CONVECTIVE BAND.
AT THIS POINT IT IS DIFFICULT TO KNOW WHETHER THIS IS THE BEGINNING OF THE FORMATION OF A SECONDARY EYEWALL.
IT IS ALSO POSSIBLE THAT THE WEAKENING OVERNIGHT WAS RELATED TO AN EYEWALL REPLACEMENT CYCLE.
THE AVERAGE OF THE LATEST OBJECTIVE AND SUBJECTIVE DVORAK T-NUMBERS INDICATE THAT INITIAL INTENSITY CAN BE ADJUSTED DOWN TO 100 KT.
AN AIR FORCE HURRICANE HUNTER PLANE WILL CHECK THE INTENSITY LATER TODAY.
THE HURRICANE STILL HAS TO MOVE OVER THE WARMEST OCEAN YET TODAY AND SATURDAY…AND THE SHEAR IS LOW AS DIAGNOSED BY THE SHIPS MODEL.
HURRICANE BILL HAS THE POTENTIAL TO RESTRENGTHEN A LITTLE BUT MOST LIKELY THE HURRICANE WILL EXPERIENCE SOME FLUCTUATIONS IN INTENSITY DURING THE NEXT 24 HOURS.
THEREAFTER…SHEAR AND A COLDER OCEAN SHOULD WORK AGAINST INTENSIFICATION AND BILL SHOULD BEGIN ITS EXTRATROPICAL TRANSITION BEYOND 72 HOURS.
HURRICANE BILL IS MOVING TOWARD THE NORTHWEST OR 325 DEGREES AT 16 KNOTS WHILE EMBEDDED IN VERY WELL-ESTABLISHED STEERING CURRENTS ASSOCIATED WITH THE AZORES-BERMUDA HIGH.
BILL IS ALREADY REACHING THE SOUTHWESTERN EDGE OF THE RIDGE AND SOON WILL BECOME STEERED NORTHWARD AND NORTHEASTWARD BY THE FLOW BETWEEN THE HIGH AND A LARGE MID-LATITUDE TROUGH DEVELOPING OVER THE EASTERN UNITED STATES.
THESE TWO FEATURES ARE BEING HANDLED CONSISTENTLY ACROSS MOST OF THE DYNAMICAL MODELS AND CONSEQUENTLY THE TRACK GUIDANCE IS TIGHTLY PACKED. THE FACT THAT TRACK GUIDANCE IS IN VERY GOOD AGREEMENT INCREASES MY CONFIDENCE IN THE TRACK FORECAST.
LARGE SWELLS GENERATED BY THIS HURRICANE WILL AFFECT A LARGE PORTION OF THE WESTERN NORTH ATLANTIC COASTAL AREA DURING THE NEXT FEW DAYS.
THESE SWELLS WILL LIKELY CAUSE EXTREMELY DANGEROUS SURF AND LIFE-THREATENING RIP CURRENTS.
HURRICANE BILL FORECAST POSITIONS AND MAX WINDS
INITIAL 21/1500Z 27.6N 66.3W 100 KT
12HR VT 22/0000Z 29.8N 67.7W 100 KT
24HR VT 22/1200Z 33.0N 68.5W 100 KT
36HR VT 23/0000Z 36.5N 68.4W 90 KT
48HR VT 23/1200Z 41.0N 66.0W 80 KT
72HR VT 24/1200Z 48.5N 52.0W 60 KT
96HR VT 25/1200Z 53.5N 27.5W 50 KT…EXTRATROPICAL
120HR VT 26/1200Z 57.5N 10.0W 40 KT…EXTRATROPICAL
August 22nd, 2009 at 8:21 am
Hurricane Bill Shifts West – Tropical Storm Force Wind Warnings For New England
HURRICANE BILL DISCUSSION NUMBER 28
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 AM AST SAT AUG 22 2009
REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE THAT BILL HAS JUST ABOUT FINISHED ITS EYEWALL REPLACEMENT CYCLE…AND NOW HAS A 48 N MI WIDE EYE.
THE AIRCRAFT ENCOUNTERED 120 KT FLIGHT-LEVEL WINDS AT 700 MB IN THE NORTHEASTERN EYEWALL…AND A DROPSONDE IN THE AREA SUGGESTS SURFACE WINDS OF 90 KT.
THE MINIMUM CENTRAL PRESSURE WAS 960 MB.
BASED ON THIS DATA…THE INITIAL INTENSITY REMAINS 90 KT.
THE CIRRUS OUTFLOW IS GOOD IN THE NORTHWESTERN SEMICIRCLE AND POOR ELSEWHERE.
BILL HAS MOVED A LITTLE TO THE LEFT OF THE PREVIOUS FORECAST…WITH AN INITIAL MOTION OF 345/19.
OTHER THAN THAT…THERE IS LITTLE CHANGE IN THE FORECAST PHILOSOPHY OR THE TRACK FORECAST GUIDANCE.
HURRICANE BILL IS EXPECTED TO RECURVE INTO THE WESTERLIES DURING THE NEXT 24-48 HR BETWEEN A LARGE DEEP-LAYER TROUGH OVER THE EASTERN UNITED STATES AND A RIDGE OVER THE CENTRAL ATLANTIC.
AFTER 48 HR…THE SYSTEM SHOULD MOVE QUICKLY EASTWARD IN THE WESTERLIES.
THE NEW FORECAST TRACK IS SLIGHTLY NORTH AND WEST OF THE PREVIOUS TRACK FOR THE FIRST 48 HR DUE TO THE INITIAL POSITION AND MOTION.
AFTER THAT TIME…THE TRACK IS SHIFTED SOUTHWARD FROM THE PREVIOUS TRACK.
THE NEW FORECAST IS DOWN THE MIDDLE OF THE DYNAMICAL GUIDANCE ENVELOPE.
BILL SHOULD REMAIN IN LIGHT VERTICAL WIND SHEAR AND OVER WARM SEA SURFACE TEMPERATURES FOR THE NEXT 12-24 HOURS…AND THUS THE INTENSITY FORECAST CALLS FOR SOME STRENGTHENING DURING THIS TIME.
AFTER 24 HR…COLDER SSTS AND INCREASING SHEAR SHOULD CAUSE BILL TO WEAKEN.
EXTRATROPICAL TRANSITION IS EXPECTED TO BEGIN AT ABOUT THE 48 HR PERIOD AND BE COMPLETE BY 72 HR…AND THE EXTRATROPICAL REMNANTS OF BILL ARE FORECAST TO GRADUALLY WEAKEN AS THEY CROSS THE ATLANTIC.
LARGE SWELLS GENERATED BY HURRICANE BILL ARE BEGINNING TO ARRIVE ALONG THE EAST COAST OF THE UNITED STATES. THESE SWELLS WILL SPREAD NORTHWARD OVER THE WEEKEND…CAUSING EXTREMELY DANGEROUS SURF AND LIFE-THREATENING RIP CURRENTS.
PLEASE CONSULT STATEMENTS ISSUED BY YOUR LOCAL WEATHER OFFICE AND METEOROLOGICAL SERVICES FOR MORE DETAILS.
THE WESTWARD SHIFT IN THE FORECAST TRACK REQUIRES A TROPICAL STORM WARNING FOR PORTIONS OF THE MASSACHUSETTS COAST…AND THE WIND SPEED PROBABILITY PRODUCT NOW SHOWS A 40 PERCENT CHANCE OF TROPICAL-STORM-FORCE WINDS IN THAT AREA.
ANY ADDITIONAL TRACK DEVIATIONS TO THE WEST WOULD REQUIRE ADDITIONAL WARNINGS ALONG THE NEW ENGLAND COAST.
HURRICANE BILL FORECAST POSITIONS AND MAX WINDS
INITIAL 22/0900Z 33.0N 68.5W 90 KT
12HR VT 22/1800Z 36.1N 68.7W 95 KT
24HR VT 23/0600Z 40.1N 67.2W 90 KT
36HR VT 23/1800Z 44.1N 63.1W 75 KT
48HR VT 24/0600Z 48.0N 55.6W 60 KT…INLAND
72HR VT 25/0600Z 51.0N 31.5W 40 KT…EXTRATROPICAL
96HR VT 26/0600Z 54.0N 14.0W 30 KT…EXTRATROPICAL
120HR VT 27/0600Z 58.0N 4.0W 20 KT…EXTRATROPICAL