Isabel Now Heading North-Northwest

[donsutherland1]

As of 11 p.m., Hurricane Isabel had continued to weaken somewhat. Her maximum winds had diminished to 120 mph. She was centered at 26.1N 70.2W or 829 miles south-southeast of Norfolk.

Over the past 24 hours, Isabel has tracked northwestward at 308 degrees. Over the past six hours her turn more to the north had continued as she headed north-northwestward at 342 degrees. A general northwest to north-northwest track should continue over the next 24 hours.

Isabel has weakened over the past 24 hours due to her having battled an area of wind shear. However, she has departed that area of wind shear and could slowly begin to regain some of her former strength over the next 24-48 hours.

In terms of Isabel’s track, I have employed model guidance (with an emphasis on the ECMWF) and analogs to sketch out a possible path. This track is as follows with relation to select locations:

<b>Charleston:</b> 255 miles east
<b>Morehead City, NC: </b>50 miles east
<b>Norfolk: </b>5 miles west
<b>Washington, DC: </b>25 miles east
<b>Philadelphia: </b>110 miles west
<b>New York City: </b>175 miles west
<b>Boston: </b>330 miles west

Overall, the most likely area for landfall will likely stretch from Morehead City to Cape Hatteras. However, it is possible that landfall could occur in eastern Virginia. Lower odds exist for landfall along the Maryland or Delaware shore.

In terms of Isabel’s maximum sustained winds at landfall, both model and analog data have been employed. Based largely on the ECMWF she may come ashore with a central pressure of between 945-950 mb. This would imply maximum sustained winds of 120 mph to 130 mph. A look at various analogs suggests somewhat lower winds on the order of 110 mph to 120 mph.

[WEATHER53]

With the track you have stated of 25 miles east of DC, what do you think the windspeed would be at that time for DCA and then BWI. Additionally, if the track was 25 miles West of DCA, what would you estimate the wind speed to be. Rainfall amounts would also be appreciated. Welcome to this site, I think you are about the 5th WWBB regular who has joined tonight.

[TheWeatherZone]

WWBB regular here. Don't yah miss everyone? I want to hear HM's thoughts, he's personally one of my favorite from the WWBB. This board is nice though, nice group of people over here.

Mike~

[johnnysunammi500]

Sitting here myself, it's just really ridiculous.

[john186292]

gee, don s. ...ur post sounds professional. Are you a met? or is it a cut and paste? whatever, welcome to the board here...i see this is ur first post. Enjoy your time with us....excellent post.
john

[john186292]

PS what is the WWBB?

[TheWeatherZone]

Wright Weather Bulletin Board

http://www.wright-weather.com

Mike~

[john186292]

thanks

[john186292]

WWBB keeps asking me for password. Is WWBB a site I have to give money tobefore geting any info from them? Is there a forum there? you guys seem to have met there, so i figure a forum somewhere there.

[HuffWx]

You need cash for the model page, not for the board. The board is nice but it is but rough at times.

Huff

[donsutherland1]

Weather53,

At this point, I'm still less confident about the exact track than the band in which the storm might travel (somewhere between 76.5W and 78.9W--120 miles west to 30 miles east of the city--by the time it reaches DC's latitude of 38.8N. For what it's worth, TPC has Isabel passing 100 miles to the west of DC. Moreover, based on today's data through 11 a.m, it appears more likely that Isabel will pass somewhat west of the city (around 40 miles or so). A better idea will probably be available tomorrow as the extent of Isabel's continuing turn to the north ahead of a turn back to the north-northwest or northwest is known.

Based on the idea that Isabel will pack maximum sustained winds of 110 mph to 120 mph upon landfall and that she will weaken somewhat slowly as she begins to accelerate, I believe that one can conservatively anticipate peak sustained winds in the 40 mph to 60 mph category, with gusts of 75 mph to 100 mph (I'm assuming a track between mine and TPC's for the estimate). Obviously, if she passes to the West or East, and how close, will make a difference. Rainfall again will depend on which side she passes and her forward speed. Certainly, 1.50"-3.50" looks likely at this point in time.

[donsutherland1]

My latest thinking on Isabel's track as of 11 p.m. is as follows (NOTE: TPC's extrapolated track is in parentheses):

Charleston: 245 miles east (275 miles east)
Morehead City, NC: 30 miles east (40 miles east)
Cape Hatteras: 30 miles west (45 miles west)
Norfolk: 5 miles west (65 miles west)
Washington, DC: 30 miles west (40 miles west)
Atlantic City: 175 miles west (180 miles west)
Philadelphia: 150 miles west (160 miles west)
New York City: 220 miles west (215 miles west)
Boston: 335 miles west (375 miles west)

[donsutherland1]

Isabel continuing to look good for a 110 mph to 120 mph landfall...

Although Isabel has been fighting off some dry air and her appearance appears somewhat less than fashionable e.g., she's in need of some eye liner to smooth over the holes in her eye wall, she continues to show signs of slow intensification.

The latest recon report found the following:

000
URNT12 KNHC 171925
VORTEX DATA MESSAGE
A. 17/1925Z
B. 30 DEG 54 MIN N
73 DEG 05 MIN W
C. 700 MB 2700 M
D. 95 KT
E. 050 DEG 70 NM
F. 140 DEG 114 KT
G. 050 DEG 064 NM
H. 955 MB
I. 8 C/ 3075 M
J. 14 C/ 3096 M
K. 13 C/ NA
L. WEAK RAGGED
M. E320/50/25
N. 12345/07
O. 0.1/2 NM
P. AF866 2113A ISABEL OB 23
MAX FL WIND 121 KT SE QUAD 1737Z.
VERY WEAK EYEWALL RADAR PRESENTATION. MANY HOLES IN
WALL STRUCTURE.

Given both the 955 MB pressure and maximum 700 MB wind speed of 121 knots, I believe that TPC will almost certainly revise her maximum winds upward in its 5 pm report. TPC might err on the side of conservatism and raise the winds to 110 mph or possibly 115 mph.

In any case, her track remains on course for a North Carolina landfall as she continues to head north-northwest.

[donsutherland1]

Just a quick note...

TPC did err on the side of conservatism and left the winds unchanged. TPC will probably wait for another recon report before making the decision to revise its report concerning Isabel's maximum sustained winds.

In fact, TPC hinted at a possible increase in winds ahead of landfall, noting "A SLIGHT INCREASE IN STRENGTH IS POSSIBLE PRIOR TO
LANDFALL."