Thomas Smith
September 13th, 2003, 07:36 AM
From the National Weather Service. They seem a little less alarmist than
the Weather Channel.
BEGIN QUOTE
000
WTNT33 KNHC 130246
TCPAT3
BULLETIN
HURRICANE ISABEL ADVISORY NUMBER 28
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM AST FRI SEP 12 2003
....ISABEL CONTINUES WESTWARD...
AT 11 PM AST...0300Z...THE CENTER OF HURRICANE ISABEL WAS LOCATED NEAR
LATITUDE 21.8 NORTH... LONGITUDE 59.5 WEST OR ABOUT 320 MILES...515
KM...NORTH-NORTHEAST OF THE NORTHERN LEEWARD ISLANDS.
ISABEL IS MOVING TOWARD THE WEST NEAR 9 MPH ...15 KM/HR. A WEST TO
WEST-NORTHWESTWARD MOTION IS EXPECTED OVER THE NEXT 24 HOURS.
MAXIMUM SUSTAINED WINDS ARE NEAR 160 MPH...260 KM/HR...WITH HIGHER GUSTS.
SATELLITE IMAGES INDICATE THAT ISABEL MAY BE WEAKENING A LITTLE...AND
ANOTHER RECONNAISSANCE AIRCRAFT WILL BE IN THE HURRICANE IN A FEW HOURS.
HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 85 MILES...140 KM...FROM THE
CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 160 MILES...260
KM.
ESTIMATED MINIMUM CENTRAL PRESSURE IS 923 MB...27.26 INCHES.
LARGE OCEAN SWELLS AND DANGEROUS SURF CONDITIONS ARE LIKELY OVER PORTIONS OF
THE LEEWARD ISLANDS...THE VIRGIN ISLANDS...AND PUERTO RICO OVER THE NEXT
SEVERAL DAYS.
REPEATING THE 11 PM AST POSITION...21.8 N... 59.5 W. MOVEMENT TOWARD...WEST
NEAR 9 MPH. MAXIMUM SUSTAINED WINDS...160 MPH. MINIMUM CENTRAL
PRESSURE... 923 MB.
THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT 5 AM
AST.
FORECASTER FRANKLIN
END QUOTE
Source: http://www.nhc.noaa.gov/text/refresh/MIATCPAT3+shtml/130246.shtml?
BEGIN QUOTE
000
WTNT43 KNHC 130245
TCDAT3
HURRICANE ISABEL DISCUSSION NUMBER 28
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT FRI SEP 12 2003
RADAR IMAGES TRANSMITTED FROM A NOAA/HURRICANE RESEARCH DIVISION FLIGHT INTO
ISABEL LATE THIS AFTERNOON SHOWED THE DEVELOPMENT OF A SECOND CONCENTRIC
EYEWALL ABOUT 20 NM OUTSIDE OF THE INNER EYEWALL. THE AIRCRAFT CREW ALSO
REPORTED A STEPPED FREQUENCY MICROWAVE RADIOMETER MEASUREMENT OF A 140 KT
SURFACE WIND LATE IN THE
AFTERNOON. CONCURRENT WITH THIS RE-DEVELOPMENT OF AN OUTER EYEWALL...THE
CORE CONVECTION IS CURRENTLY WEAKENING AS IT DID LAST NIGHT AT THIS TIME. IN
ADDITION...MICROWAVE IMAGERY INDICATES THAT SOME DRY AIR HAS BEEN
INFILTRATING THE CIRCULATION. SUBJECTIVE DVORAK T-NUMBERS ARE DOWN TO
6.0...AND THE LATEST CIMSS ADVANCED OBJECTIVE DVORAK 3-HR AVERAGE T NUMBER
IS ALSO 6.0...WELL BELOW CATEGORY FIVE INTENSITY. I VERY MUCH DOUBT THAT
ISABEL STILL HAS WINDS OF 140 KT...BUT SINCE ANOTHER AIRCRAFT WILL BE IN THE
HURRICANE IN JUST THREE HOURS...WE WILL WAIT FOR CONFIRMATION OF THIS
APPARENT WEAKENING TREND. IT IS VIRTUALLY UNHEARD OF FOR A HURRICANE TO
REMAIN AT CATEGORY FIVE STRENGTH FOR MORE THAN 30 HOURS. HOWEVER...ISABEL IS
EXPECTED TO REMAIN A MAJOR HURRICANE THROUGHOUT THE FORECAST PERIOD.
THE INITIAL MOTION IS 275/8. ISABEL REMAINS SOUTH OF A DEEP-LAYER
ANTICYCLONE THAT IS PROVIDING THE WESTWARD STEERING CURRENT. THIS
ANTICYCLONE CONTINUES WESTWARD IN STEP WITH THE HURRICANE...AND MODEL
GUIDANCE IS IN EXCELLENT AGREEMENT ON A WEST TO
WEST-NORTHWEST TRACK FOR THE NEXT 72 HOURS. BY 72 HOURS...THE EVOLUTION OF
A MID- TO UPPER-LEVEL LOW CURRENTLY OVER THE CAROLINAS COULD PLAY A KEY ROLE
IN WHAT PORTION OF THE U.S. EAST COAST WOULD EVENTUALLY BE AFFECTED BY
ISABEL. THE GFS AND NOGAPS MODELS ARE VERY SIMILAR IN HOLDING THIS FEATURE
IN PLACE ALMOST A DAY LONGER THAN THE UKMET...WITH THE RESULT THAT THE
FORMER TWO MODELS TURN ISABEL MUCH MORE SHARPLY NORTHWARD THAN THE UKMET.
THE GFDL TURNS ISABEL EVEN MORE SHARPLY THAN THE GFS AND NOGAPS MODELS...AND
THE EUROPEAN MODEL ALSO SEEMS TO FAVOR AN EARLIER TURN NORTH. THE OFFICIAL
FORECAST HAS BEEN BEEN SHIFTED TO THE RIGHT OF THE PREVIOUS ADVISORY
TRACK...BUT IS STILL CLOSER TO THE UKMET THAN THE OTHER GUIDANCE. IN PART
THIS IS TO MAINTAIN CONTINUITY WITH PREVIOUS FORECASTS...BUT ALSO BECAUSE
THE UKMET HAS BEEN PRESENTING A MORE CONSISTENT SOLUTION OVER THE PAST
COUPLE OF DAYS THAN HAVE THE OTHER MODELS.
FORECASTER FRANKLIN
FORECAST POSITIONS AND MAX WINDS
INITIAL 13/0300Z 21.8N 59.5W 140 KT
12HR VT 13/1200Z 22.2N 60.9W 135 KT
24HR VT 14/0000Z 22.8N 63.0W 130 KT
36HR VT 14/1200Z 23.4N 65.1W 130 KT
48HR VT 15/0000Z 24.0N 67.0W 130 KT
72HR VT 16/0000Z 25.0N 70.0W 125 KT
96HR VT 17/0000Z 27.0N 72.5W 115 KT
120HR VT 18/0000Z 29.5N 74.5W 105 KT
END QUOTE
Source: http://www.nhc.noaa.gov/text/refresh/MIATCDAT3+shtml/130245.shtml?
Tom Smith
the Weather Channel.
BEGIN QUOTE
000
WTNT33 KNHC 130246
TCPAT3
BULLETIN
HURRICANE ISABEL ADVISORY NUMBER 28
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM AST FRI SEP 12 2003
....ISABEL CONTINUES WESTWARD...
AT 11 PM AST...0300Z...THE CENTER OF HURRICANE ISABEL WAS LOCATED NEAR
LATITUDE 21.8 NORTH... LONGITUDE 59.5 WEST OR ABOUT 320 MILES...515
KM...NORTH-NORTHEAST OF THE NORTHERN LEEWARD ISLANDS.
ISABEL IS MOVING TOWARD THE WEST NEAR 9 MPH ...15 KM/HR. A WEST TO
WEST-NORTHWESTWARD MOTION IS EXPECTED OVER THE NEXT 24 HOURS.
MAXIMUM SUSTAINED WINDS ARE NEAR 160 MPH...260 KM/HR...WITH HIGHER GUSTS.
SATELLITE IMAGES INDICATE THAT ISABEL MAY BE WEAKENING A LITTLE...AND
ANOTHER RECONNAISSANCE AIRCRAFT WILL BE IN THE HURRICANE IN A FEW HOURS.
HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 85 MILES...140 KM...FROM THE
CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 160 MILES...260
KM.
ESTIMATED MINIMUM CENTRAL PRESSURE IS 923 MB...27.26 INCHES.
LARGE OCEAN SWELLS AND DANGEROUS SURF CONDITIONS ARE LIKELY OVER PORTIONS OF
THE LEEWARD ISLANDS...THE VIRGIN ISLANDS...AND PUERTO RICO OVER THE NEXT
SEVERAL DAYS.
REPEATING THE 11 PM AST POSITION...21.8 N... 59.5 W. MOVEMENT TOWARD...WEST
NEAR 9 MPH. MAXIMUM SUSTAINED WINDS...160 MPH. MINIMUM CENTRAL
PRESSURE... 923 MB.
THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT 5 AM
AST.
FORECASTER FRANKLIN
END QUOTE
Source: http://www.nhc.noaa.gov/text/refresh/MIATCPAT3+shtml/130246.shtml?
BEGIN QUOTE
000
WTNT43 KNHC 130245
TCDAT3
HURRICANE ISABEL DISCUSSION NUMBER 28
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT FRI SEP 12 2003
RADAR IMAGES TRANSMITTED FROM A NOAA/HURRICANE RESEARCH DIVISION FLIGHT INTO
ISABEL LATE THIS AFTERNOON SHOWED THE DEVELOPMENT OF A SECOND CONCENTRIC
EYEWALL ABOUT 20 NM OUTSIDE OF THE INNER EYEWALL. THE AIRCRAFT CREW ALSO
REPORTED A STEPPED FREQUENCY MICROWAVE RADIOMETER MEASUREMENT OF A 140 KT
SURFACE WIND LATE IN THE
AFTERNOON. CONCURRENT WITH THIS RE-DEVELOPMENT OF AN OUTER EYEWALL...THE
CORE CONVECTION IS CURRENTLY WEAKENING AS IT DID LAST NIGHT AT THIS TIME. IN
ADDITION...MICROWAVE IMAGERY INDICATES THAT SOME DRY AIR HAS BEEN
INFILTRATING THE CIRCULATION. SUBJECTIVE DVORAK T-NUMBERS ARE DOWN TO
6.0...AND THE LATEST CIMSS ADVANCED OBJECTIVE DVORAK 3-HR AVERAGE T NUMBER
IS ALSO 6.0...WELL BELOW CATEGORY FIVE INTENSITY. I VERY MUCH DOUBT THAT
ISABEL STILL HAS WINDS OF 140 KT...BUT SINCE ANOTHER AIRCRAFT WILL BE IN THE
HURRICANE IN JUST THREE HOURS...WE WILL WAIT FOR CONFIRMATION OF THIS
APPARENT WEAKENING TREND. IT IS VIRTUALLY UNHEARD OF FOR A HURRICANE TO
REMAIN AT CATEGORY FIVE STRENGTH FOR MORE THAN 30 HOURS. HOWEVER...ISABEL IS
EXPECTED TO REMAIN A MAJOR HURRICANE THROUGHOUT THE FORECAST PERIOD.
THE INITIAL MOTION IS 275/8. ISABEL REMAINS SOUTH OF A DEEP-LAYER
ANTICYCLONE THAT IS PROVIDING THE WESTWARD STEERING CURRENT. THIS
ANTICYCLONE CONTINUES WESTWARD IN STEP WITH THE HURRICANE...AND MODEL
GUIDANCE IS IN EXCELLENT AGREEMENT ON A WEST TO
WEST-NORTHWEST TRACK FOR THE NEXT 72 HOURS. BY 72 HOURS...THE EVOLUTION OF
A MID- TO UPPER-LEVEL LOW CURRENTLY OVER THE CAROLINAS COULD PLAY A KEY ROLE
IN WHAT PORTION OF THE U.S. EAST COAST WOULD EVENTUALLY BE AFFECTED BY
ISABEL. THE GFS AND NOGAPS MODELS ARE VERY SIMILAR IN HOLDING THIS FEATURE
IN PLACE ALMOST A DAY LONGER THAN THE UKMET...WITH THE RESULT THAT THE
FORMER TWO MODELS TURN ISABEL MUCH MORE SHARPLY NORTHWARD THAN THE UKMET.
THE GFDL TURNS ISABEL EVEN MORE SHARPLY THAN THE GFS AND NOGAPS MODELS...AND
THE EUROPEAN MODEL ALSO SEEMS TO FAVOR AN EARLIER TURN NORTH. THE OFFICIAL
FORECAST HAS BEEN BEEN SHIFTED TO THE RIGHT OF THE PREVIOUS ADVISORY
TRACK...BUT IS STILL CLOSER TO THE UKMET THAN THE OTHER GUIDANCE. IN PART
THIS IS TO MAINTAIN CONTINUITY WITH PREVIOUS FORECASTS...BUT ALSO BECAUSE
THE UKMET HAS BEEN PRESENTING A MORE CONSISTENT SOLUTION OVER THE PAST
COUPLE OF DAYS THAN HAVE THE OTHER MODELS.
FORECASTER FRANKLIN
FORECAST POSITIONS AND MAX WINDS
INITIAL 13/0300Z 21.8N 59.5W 140 KT
12HR VT 13/1200Z 22.2N 60.9W 135 KT
24HR VT 14/0000Z 22.8N 63.0W 130 KT
36HR VT 14/1200Z 23.4N 65.1W 130 KT
48HR VT 15/0000Z 24.0N 67.0W 130 KT
72HR VT 16/0000Z 25.0N 70.0W 125 KT
96HR VT 17/0000Z 27.0N 72.5W 115 KT
120HR VT 18/0000Z 29.5N 74.5W 105 KT
END QUOTE
Source: http://www.nhc.noaa.gov/text/refresh/MIATCDAT3+shtml/130245.shtml?
Tom Smith