Hurricane Isabel weak (still strong Cat 4) 9/13/03

Hey tokenlib, you want to start another thread--FNC just reported sea level wind speeds are back up to Cat 5 160 mph again. Sorry I can't get that to you in all caps text just now.

Then again, you could keep starting new threads in all caps every six hours with the updated advisories.

Any updates on the storm? Is it turning north?

000 WTNT61 KNHC 131807 TCUAT BULLETIN HURRICANE ISABEL TROPICAL CYCLONE UPDATE NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 210 PM EDT SAT SEP 6 2003 RECENT REPORTS FROM AIR FORCE RESERVE AND NOAA HURRICANE HUNTER AIRCRAFT INDICATE FLIGHT-LEVEL WINDS OF 158 KT AND 157 KT... RESPECTIVELY. ALSO...DROPSONDE WIND REPORTS INDICATE WINDS OF 167 KT...OR 192 MPH...JUST A FEW HUNDRED FEET ABOVE THE SURFACE. BASED ON THIS INFORMATION...THE INTENSITY OF HURRICANE ISABEL IS BEING INCREASED TO 140 KT...OR 160 MPH...AS OF 2 PM EDT...1800Z. THIS MAKES ISABEL A CATEGORY 5 HURRICANE AGAIN. FORECASTER STEWART

criminy! batten down the hatches!

The 5 pm first burst:

WTNT23 KNHC 132023

TCMAT3

HURRICANE ISABEL FORECAST/ADVISORY NUMBER 31

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL132003

2100Z SAT SEP 13 2003

HURRICANE CENTER LOCATED NEAR 22.6N 62.6W AT 13/2100Z

POSITION ACCURATE WITHIN 15 NM

PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT 10 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 932 MB

EYE DIAMETER 30 NM

MAX SUSTAINED WINDS 140 KT WITH GUSTS TO 170 KT.

64 KT....... 80NE 70SE 70SW 80NW.

50 KT.......105NE 90SE 90SW 105NW.

34 KT.......150NE 150SE 130SW 150NW.

12 FT SEAS..325NE 325SE 275SW 300NW.

WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL

MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 22.6N 62.6W AT 13/2100Z

AT 13/1800Z CENTER WAS LOCATED NEAR 22.4N 62.1W

FORECAST VALID 14/0600Z 23.0N 64.2W

MAX WIND 140 KT...GUSTS 170 KT.

64 KT... 80NE 70SE 70SW 80NW.

50 KT...105NE 90SE 90SW 105NW.

34 KT...150NE 150SE 130SW 150NW.

FORECAST VALID 14/1800Z 23.7N 66.2W

MAX WIND 140 KT...GUSTS 170 KT.

64 KT... 80NE 70SE 70SW 80NW.

50 KT...105NE 90SE 90SW 105NW.

34 KT...150NE 150SE 130SW 150NW.

FORECAST VALID 15/0600Z 24.4N 68.0W

MAX WIND 135 KT...GUSTS 165 KT.

64 KT... 80NE 70SE 70SW 80NW.

50 KT...105NE 90SE 90SW 105NW.

34 KT...150NE 150SE 130SW 150NW.

FORECAST VALID 15/1800Z 25.2N 69.4W

MAX WIND 135 KT...GUSTS 165 KT.

50 KT...110NE 95SE 95SW 110NW.

34 KT...160NE 160SE 140SW 160NW.

FORECAST VALID 16/1800Z 26.5N 71.5W

MAX WIND 130 KT...GUSTS 160 KT.

50 KT...110NE 95SE 95SW 110NW.

34 KT...160NE 160SE 140SW 160NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 275 NM

ON DAY 4 AND 375 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 17/1800Z 29.5N 73.0W

MAX WIND 125 KT...GUSTS 155 KT.

OUTLOOK VALID 18/1800Z 33.5N 75.0W

MAX WIND 105 KT...GUSTS 130 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 22.6N 62.6W

NEXT ADVISORY AT 14/0300Z

FORECASTER STEWART

Never sat through a hurricane in the middle of the state (did a CAT 2 out on the Banks and of course Hugo back in the late 80s). We were living in the mountains during Fran and I remember Hugo in Charlotte many years ago, so this will be a new experience for us.

Back up to CAT 5 (but it may miss NC/VA after all...)WTNT43 KNHC 132046

TCDAT3

HURRICANE ISABEL DISCUSSION NUMBER 31

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

5 PM EDT SAT SEP 13 2003

THERE HAS BEEN A PLETHORA OF WIND DATA FROM BOTH THE AIR FORCE

RESERVE AND NOAA HURRICANE HUNTERS THIS AFTERNOON. IN SUMMARY...THE

AIRCRAFT FOUND MAXIMUM 700 MB FLIGHT-LEVEL WINDS OF 157 AND 158 KT

...ALONG WITH A DROPSONDE WIND VALUE OF 178 KT...OR 205 MPH...AT

879 MB...ALL OF WHICH CORRESPONDS TO SURFACE WIND ESTIMATES OF

141-142 KT. THEREFORE...THE INITIAL INTENSITY HAS BEEN INCREASED TO

140 KT/160 MPH...SO ISABEL IS A CATEGORY 5 HURRICANE ONCE AGAIN.

THE INITIAL MOTION ESTIMATE IS NOW 285/11. THIS MAY BE A SHORT-TERM

ACCELERATION DUE TO THE EYE CONTRACTING DOWN IN SIZE AND

RE-ADJUSTING WITHIN THE CENTRAL DEEP CONVECTION. HOWEVER...THE 285

DEGREES MOTION NOW APPEARS TO BE A STEADY TREND. THE NEW 12Z GFS

FORECAST TRACK HAS COME IN ALMOST ON TOP OF THE PREVIOUS OFFICAL

FORECAST THROUGH 48 HOURS AND THEN IS LEFT OF THE TRACK BY 72 HOURS

...BEFORE HOOKING BACK ACROSS THE PREVIOUS FORECAST TRACK AND

ACCELERATING ISABEL NORTHWARD. THIS SCENARIO IS ALSO IDENTICAL TO

THE 12Z ETA MODEL RUN. SIMILARLY BUT TO THE RIGHT OF THE PREVIOUS

FORECAST ARE THE GFDL...NOGAPS...UKMET...AND CANADIAN MODELS.

INTERESTINGLY ENOUGH...ALL OF THE MODELS AGREE ON A SHARP DECREASE

IN FORWARD SPEED OR A STALL IN 60-72 HOURS...AND THEN RAPIDLY

ACCELERATING ISABEL NORTH OR NORTH-NORTHWESTWARD AFTER 96 HOURS AS

THE CYCLONE IS FORECAST TO GET PICKED UP BY AN APPROACHING

SHORTWAVE TROUGH FROM THE WEST AND A BUILDING RIDGE TO THE EAST.

HOWEVER...THERE IS STILL SOME UNCERTAINTY ON THE CURRENT STRENGTH

OF THE SUBTROPICAL RIDGE TO THE NORTH OF ISABEL...SO IT IS PRUDENT

TO WAIT UNTIL ALL OF THE NOAA GULFSTREAM-IV DROPSONDE DATA MAKE IT

INTO THE 14/00Z MODELS. THE OFFICIAL FORECAST TRACK IS JUST AN

UPDATE OF THE PREVIOUS TRACK THROUGH 96 HOURS...WITH A LITTLE MORE

NORTHWARD ACCELERATION INDICATED AT 120 HOURS AS A COURSE OF LEAST

REGRET. NOTE -- NONE OF THE NHC MODEL GUIDANCE HAS ISABEL OVER LAND

BY 120 HOURS.

WHILE SOME SLIGHT STRENGTHENING IS POSSIBLE IN THE NEXT 12 HOURS...

THERE IS NO WAY TO REALLY TIME THE DEVELOPMENT OF ANOTHER EYEWALL

REPLACEMENT CYCLE. IN THE LONG RUN...UPPER-LEVEL CONDITIONS ARE

FORECAST TO REMAIN FAVORABLE FOR AT LEAST THE NEXT 48-72 HOURS...

WITH THE HURRICANE ALSO MOVING OVER WARMER WATER. THEREFORE...A

STEADY INTENSITY OR ONLY VERY SLOW WEAKENING IS EXPECTED FOR THE

NEXT COUPLE OF DAYS. BY 120 HOURS...ISABEL MAY BEGIN TO

EXPERIENCING UPPER-LEVEL SOUTH TO SOUTHWESTERLY SHEAR...WHICH

SHOULD BRING ABOUT MORE RAPID WEAKENING. HOWEVER...ISABEL IS STILL

EXPECTED TO REMAIN A MAJOR HURRICANE THOUGHOUT THE FORECAST PERIOD.

FORECASTER STEWART

FORECAST POSITIONS AND MAX WINDS

INITIAL 13/2100Z 22.6N 62.6W 140 KT

12HR VT 14/0600Z 23.0N 64.2W 140 KT

24HR VT 14/1800Z 23.7N 66.2W 140 KT

36HR VT 15/0600Z 24.4N 68.0W 135 KT

48HR VT 15/1800Z 25.2N 69.4W 135 KT

72HR VT 16/1800Z 26.5N 71.5W 130 KT

96HR VT 17/1800Z 29.5N 73.0W 125 KT

120HR VT 18/1800Z 33.5N 75.0W 105 KT

Oh there will still be something here. Maybe not as many of those houses built in such a rush at substandard levels that infest the Banks from Nags Head to Currituck, but all the good stuff will still be here. BTW, although the play will be closed, the Lost Colony site and the Elizabeth II in Manteo are good places to visit. If you've got a few minutes ride down to Wanchese as well.

Yes, Agnes got hung up in the bay and dumped all over itself for a period of days.

Gloria in 1986 had some damaging sustained winds and did a number on some properties in Ocean City.

NOAA jpeg of track.

It may still miss but they've got it just south of Ocracoke on Thursday. If it hits Hatteras or northward it will go onto Virginia. Otherwise we could have a worse repeat of Fran

Back up to CAT 5 (but it may miss NC/VA after all...)WTNT43 KNHC 132046

tcdat3

Hurricane Isabel discussion number 31
nws tpc/national hurricane center Miami fl
5 pm edt sat sep 13 2003

there has been a plethora of wind data from both the air force reserve and noaa hurricane hunters this afternoon. In summary...the aircraft found maximum 700 mb flight-level winds of 157 and 158 kt ...along with a dropsonde wind value of 178 kt...or 205 mph...at 879 mb...all of which corresponds to surface wind estimates of 141-142 kt. Therefore...the initial intensity has been increased to 140 kt/160 mph...so isabel is a category 5 hurricane once again.

The initial motion estimate is now 285/11. This may be a short-term acceleration due to the eye contracting down in size and re-adjusting within the central deep convection. However...the 285 degrees motion now appears to be a steady trend. The new 12z gfs forecast track has come in almost on top of the previous offical forecast through 48 hours and then is left of the track by 72 hours ...before hooking back across the previous forecast track and accelerating Isabel northward. This scenario is also identical to the 12z eta model run. Similarly but to the right of the previous
forecast are the gfdl...nogaps...ukmet...and canadian models.

Interestingly enough...all of the models agree on a sharp decrease in forward speed or a stall in 60-72 hours...and then rapidly accelerating Isabel north or north-northwestward after 96 hours as the cyclone is forecast to get picked up by an approaching shortwave trough from the west and a building ridge to the east.

However...there is still some uncertainty on the current strength of the subtropical ridge to the north of Isabel...so it is prudent to wait until all of the noaa gulfstream-iv dropsonde data make it into the 14/00z models. The official forecast track is just an update of the previous track through 96 hours...with a little more
northward acceleration indicated at 120 hours as a course of least regret. Note—none of the nhc model guidance has Isabel over land by 120 hours.

While some slight strengthening is possible in the next 12 hours... There is no way to really time the development of another eyewall replacement cycle. In the long run...upper-level conditions are forecast to remain favorable for at least the next 48-72 hours...

With the hurricane also moving over warmer water. Therefore...a steady intensity or only very slow weakening is expected for the next couple of days. By 120 hours...Isabel may begin toexperiencing upper-level south to southwesterly shear...which should bring about more rapid weakening. However...Isabel is still expected to remain a major hurricane throughout the forecast period.

Forecaster stewart

forecast positions and max winds

initial 13/2100z 22.6n 62.6w 140 kt

12hr vt 14/0600z 23.0n 64.2w 140 kt

24hr vt 14/1800z 23.7n 66.2w 140 kt

36hr vt 15/0600z 24.4n 68.0w 135 kt

48hr vt 15/1800z 25.2n 69.4w 135 kt

72hr vt 16/1800z 26.5n 71.5w 130 kt

96hr vt 17/1800z 29.5n 73.0w 125 kt

120hr vt 18/1800z 33.5n 75.0w 105 kt

bump,,looks like landfall next fri or sat?

Thanks for the guidance. Make sure your local Dept. of Tourism knows you're doing your part ;) I will be praying for the safety of all our NC/VA FReepers and their neighbors.

Thank you for decaping the TPC/NHC statements!