Earl a Category 4 storm again

By: Dr. Jeff Masters , 9:23 PM GMT on September 01, 2010

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Hurricane Earl has regained Category 4 strength this afternoon, and continues on a steady northwest path towards the North Carolina coast. Recent satellite imagery shows that Earl has become more symmetrical, with improved upper-level outflow and no signs of dry air wrapping into the core. The improved appearance is probably due to lower wind shear. Latest wind shear tendency imagery from the University of Wisconsin CIMSS group shows that shear on the southwest side of Earl has fallen by about 10 knots over the past 24 hours.


Figure 1. Afternoon satellite image of Earl.

Forecast for Earl
The latest set of model runs from 8am EDT (12Z) this morning shows little change to Earl's track. Thus, my write-up of the possible impacts to North Carolina, New England, and Canada in this morning's post remain unchanged. The latest SHIPS model forecast shows wind shear will remain moderate, about 15 knots, through Friday afternoon. This should allow Earl to maintain major hurricane status as it passes North Carolina early Friday morning. By Friday night, as Earl gets caught in the jet stream and accelerates to the northeast, wind shear will rise to 20 - 30 knots and ocean temperatures will plunge to 20°C, resulting in considerable weakening. Earl will still probably be a Category 1 or 2 hurricane early Saturday morning, when it will make its closest approach to New England. Earl is more likely to be a strong tropical storm or weak Category 1 hurricane early Saturday afternoon, when it is expected to make landfall in Nova Scotia, Canada.

Earl is a large hurricane, which gives it a higher potential for storm surge damage than a smaller hurricane with the same top winds. One measure of a storm's power, useful for gauging storm surge threat, is to measure the speed of the winds and multiply by the area over which those winds blow. This total is called the Integrated Kinetic Energy (IKE). Based on the storm's IKE, one can come up with a scale from 0 - 6 rating the storm's destructive power from its storm surge. A separate rating can be given to the destructive potential of the storm's winds. The IKE value of 112 Terrajoules for Earl, at 3:30pm EDT today, gives its storm surge a destructive power of 5.0 on a scale of 0 - 6. Earl's winds have a lower destructive power, 3.4 on a scale of 0 - 6. Let's hope the right front quadrant of Earl, where the main storm surge would occur, stays offshore! For comparison, the small Category 5 Hurricane Camille of 1969 had an IKE of 80 Terrajoules, and the very large Category 2 Hurricane Ike of 2008 had an IKE of 116 Terrajoules--similar to Category 3 Earl's.

Fiona
Tropical Storm Fiona is struggling due to high wind shear, courtesy of strong upper-level northerly winds from Hurricane Earl's outflow. The latest Hurricane Hunter center fix at 1:29pm EDT found Fiona had weakened some, with a central pressure of 999 mb. This is a rise of 1 mb from this morning. The wind shear analysis from the University of Wisconsin CIMSS group shows that shear has increased to a moderately high 15 - 20 knots this afternoon. Satellite loops show the classic signature of a tropical storm experiencing high wind shear--an exposed center of circulation, and all the heavy thunderstorms pushed to one side (the south side in this case). Martinique radar shows that the outer bands from Fiona are bringing heavy rain squalls to the same islands of the northern Lesser Antilles that were affected by Earl. Our wundermap for the northern Lesser Antilles shows no stations recorded winds over 20 mph this afternoon, though there was no reporting station on Barbuda, the island closest to Fiona.

Forecast for Fiona
Moderate wind shear and dry air should keep Fiona from attaining hurricane status over the next two days, as big brother Earl continues to bring high wind shear. The shear may be strong enough to destroy Fiona, as predicted by the NHC. However, by this weekend, Earl may pull far enough away for shear to drop and Fiona to survive. The 4 - 5 day track forecast is highly uncertain, as there is a large spread in the model solutions. It is possible Fiona may pose a threat to Bermuda on Saturday or Sunday, and the storm could wander for a week or more in the waters between Bermuda and the U.S. East Coast.


Figure 2. Afternoon satellite image of Fiona.

Tropical Storm Gaston forms
Tropical Storm Gaston developed enough heavy thunderstorms near its center this afternoon to get a name, and appears destined to become Hurricane Gaston by early next week. Water vapor satellite images show a large area of dry air to the north and west of Gaston, and this dry air will be the dominant inhibiting factor for development. The latest SHIPS model forecast predicts shear will remain moderate, 10 - 15 knots, for the next four days, and perhaps fall to the low range 4 - 5 days from now. Gaston is over warm 28°C waters, and should be able to steadily intensify into a hurricane by Saturday or Sunday, as predicted by the many of the intensity models. Gaston may threaten the northern Lesser Antilles Islands as early as Tuesday.

Next post
I'll have an update in the morning, and Dr. Rob Carver will have a late night update tonight.

Jeff Masters

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Quoting Levi32:


That's 2 hours old now. This is more recent and looks even better.


If he was well out to sea, I would say he is beautiful and awe-inspiring. Looking at where he is now... its more akin to looking at a nuclear weapon's mushroom cloud. It is awe-inspiring, but at the same time, very foreboding.
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1755. Patrap
EARL Floater - Rainbow Color Infrared Loop
Member Since: July 3, 2005 Posts: 423 Comments: 128240
TWC says that their could be a storm surge of 3-6 feet that could over wash the road that connects to the main land in the outer banks.
Member Since: August 14, 2010 Posts: 10 Comments: 16968
Quoting VBgirl:
I'm in Kill Devil Hills on vacation at parents beach house. There is a part of me that really, really wants to stay. Not leaving unless they evacuate residents. We are between the beach road and the bypass.

Repost

Forgot to quote who I was trying to talk to, my bad.
OMG, What are you even thinking??? Leave now. There is absolutely no reason to stay with a Cat 4 Hurricane staring you in the face. It is not even a question? Go! You are putting yourself in the eye of potential "no way out" scenario when it will be too late. If you were inland, different story, but you are not!! Be smart..
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Quoting leo305:


yea but you don't tend to see EF4 tornadoes' in a hurricane especially the eye wall..
When was Earl true to form in anything?
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Quoting sammywammybamy:
Cyclone Oz is Crossing the Bridge into OBX.
This should be interesting.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
1749. hydrus
Quoting PSLFLCaneVet:
Wholeheartedly agree. To go from hot and muggy, to cold was really odd. Hi neighbor!
Same thing happened in Hazel. But it was even more pronounced.
Member Since: September 27, 2007 Posts: 1 Comments: 21173
1748. leddyed
Quoting RadarRich:
Quoting Greyelf:

Speaking of crazies -- anyone checked a live feed of CycloneOz?


He just crossed onto Roanoke Island - not quite to the Outer Banks island yet, and is stopping to top off his gas tank.



Where can we fing that link for Cyclone Oz? Sorry for the repost question, but where is his site/link, thanks again, anyone.?

Link
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Quoting RecordSeason:
1660:

most interesting of those is this:

944mb 142kts


that is the highest pressure among the cat5 force readings, so it implies at the surface.

It could be a water spout.
? Noooo. That's the pressure, at altitude, the dropsonde as it fell. The single highest pressure observation is at the surface. (Dropsondes don't go back up...)
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Quoting CosmicEvents:
Here we go.
Every storm somehow has a damsel in distress.
The blog sadly wasted valuable time dealing with what turned out to be several fakes during Katrina.


But this one isn't new to the blog and has made posts before... It could be a fake but I don't know.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Quoting thelmores:


I am a nutt, would risk a lot...... but the imagery from Earl even scares me!

If I was on the outer banks, I would be making preparations to depart.....

Not saying I would depart, just saying I would be making preparations to do so!

But I having a feeling with the latest round of intensification, mandatory evacs will be spreading!


Yes, and the return of a solid NW movement
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Quoting charlottefl:
I wouldn't be on a barrier Island during any hurricane period. May sound extreme, but think about where you're at, surrounded by ocean, and no where to go for help if you need it. It's better to evac a few miles inland. IMHO.

Barrier Island = large sand dune.
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Anyone on the OBX better git.

Extreme impact.

Member Since: June 9, 2007 Posts: 4 Comments: 15889
1739. xcool
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 02 SEP 2010 Time : 011500 UTC
Lat : 13:00:12 N Lon : 37:38:18 W


CI# /Pressure/ Vmax
3.3 / 996.4mb/ 51.0kt


Final T# Adj T# Raw T#
3.3 3.4 3.4

Latitude bias adjustment to MSLP : +0.0mb

Center Temp : -5.7C Cloud Region Temp : -36.1C

Scene Type : SHEAR (0.04^ TO DG)

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF


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1738. hydrus
Quoting leo305:


yea but you don't tend to see EF4 tornadoes' in a hurricane especially the eye wall..
I certainly hope not...lol
Member Since: September 27, 2007 Posts: 1 Comments: 21173
Quoting Patrap:
I wouldnt get to fussy over SSS numbers. As Earl is Piling up a Lotta water and thats combined with Wave action is going to take some Lives if folks dont react tomorrow and get outta dodge.

Its the Impact that counts always,,K was a Cat 3 with a 30 ft Surge and well,thats not the best indicator of impact the SSS.

Its designed for wind loading on structures,,not surge with wave action.





Read earlier that Earl was producing waves of 40 feet in the open ocean.
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1736. ussual
Last 24 hours in Charleston, SC

24 Hour Summary
Time
EDT (UTC) Temperature
F (C) Dew Point
F (C) Pressure
Inches (hPa) Wind
MPH Weather
Latest 10 PM (2) Sep 01 77.0 (25.0) 71.1 (21.7) 30.01 (1016) ENE 6
9 PM (1) Sep 01 78.1 (25.6) 71.1 (21.7) 29.99 (1015) NE 6
8 PM (0) Sep 01 81.0 (27.2) 70.0 (21.1) 29.99 (1015) ENE 9
7 PM (23) Sep 01 84.0 (28.9) 69.1 (20.6) 30 (1015) E 10
6 PM (22) Sep 01 86.0 (30.0) 70.0 (21.1) 29.99 (1015) E 13
5 PM (21) Sep 01 89.1 (31.7) 66.0 (18.9) 30 (1015) E 14
4 PM (20) Sep 01 90.0 (32.2) 70.0 (21.1) 30 (1015) E 13
3 PM (19) Sep 01 89.1 (31.7) 70.0 (21.1) 30.02 (1016) SE 9
2 PM (18) Sep 01 91.0 (32.8) 64.9 (18.3) 30.04 (1017) NE 10
1 PM (17) Sep 01 90.0 (32.2) 66.0 (18.9) 30.06 (1017) NE 9
Noon (16) Sep 01 89.1 (31.7) 66.9 (19.4) 30.08 (1018) ENE 5
11 AM (15) Sep 01 87.1 (30.6) 68.0 (20.0) 30.09 (1018) Variable 3
10 AM (14) Sep 01 82.9 (28.3) 70.0 (21.1) 30.09 (1018) N 5
9 AM (13) Sep 01 77.0 (25.0) 72.0 (22.2) 30.09 (1018) NNW 5 haze
8 AM (12) Sep 01 73.0 (22.8) 70.0 (21.1) 30.08 (1018) Calm mist
7 AM (11) Sep 01 70.0 (21.1) 69.1 (20.6) 30.07 (1018) Calm mist
6 AM (10) Sep 01 70.0 (21.1) 69.1 (20.6) 30.07 (1018) Calm mist
5 AM (9) Sep 01 70.0 (21.1) 69.1 (20.6) 30.06 (1017) Calm mist
4 AM (8) Sep 01 71.1 (21.7) 70.0 (21.1) 30.07 (1018) Calm mist
3 AM (7) Sep 01 71.1 (21.7) 70.0 (21.1) 30.07 (1018) Calm
2 AM (6) Sep 01 71.1 (21.7) 69.1 (20.6) 30.09 (1018) NNW 5 mist
1 AM (5) Sep 01 72.0 (22.2) 69.1 (20.6) 30.11 (1019) Calm
Midnight (4) Sep 01 73.9 (23.3) 70.0 (21.1) 30.12 (1019) Calm
Oldest 11 PM (3) Aug 31 75.0 (23.9) 70.0 (21.1) 30.12 (1019) Calm
Member Since: Posts: Comments:
Quoting ftpiercecane:

The cold front that followed wilma was crazy, in the mid 50's that night.
Wholeheartedly agree. To go from hot and muggy, to cold was really odd. Hi neighbor!
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Quoting VBgirl:
I'm in Kill Devil Hills on vacation at parents beach house. There is a part of me that really, really wants to stay. Not leaving unless they evacuate residents. We are between the beach road and the bypass.
Here we go.
Every storm somehow has a damsel in distress.
The blog sadly wasted valuable time dealing with what turned out to be several fakes during Katrina.
Member Since: Posts: Comments:
1733. leo305
Quoting ADCS:


You have to correlate it with angle. That means that where the pressure in the storm is 905 mb, there are 177 mph winds. That's not the surface pressure.


CAT 5 winds almost at the surface
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1732. angiest
Quoting leo305:


a waterspout with CAT 5 winds?? in a hurricane?


waterspouts in a hurricane seem unlikely.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
1731. angiest
Quoting leo305:


a waterspout with CAT 5 winds?? in a hurricane?


waterspouts in a hurricane seem unlikely.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
1729. hydrus
Quoting CosmicEvents:
I imagine in the 11PM discussion we'll get an upgrade in winds by 5-10knots, and the standard boilerplate along the lines of "Earl may attain Category 5 status but these things are too uncertain to predict and due to fluctuations in eyewall structure". What else can they say?
I am going with at least 150 mph on the 11.
Member Since: September 27, 2007 Posts: 1 Comments: 21173
I wouldn't be on a barrier Island during any hurricane period. May sound extreme, but think about where you're at, surrounded by ocean, and no where to go for help if you need it. It's better to evac a few miles inland. IMHO.
Member Since: Posts: Comments:
Bada bing! We've surpassed 50.

Season total ACE

01L (Alex): 6.7825
03L (Bonnie): 0.3675
04L (Colin): 1.9450
06L (Danielle): 21.7950
07L (Earl): 18.2200
08L (Fiona): 1.3950
09L (Gaston): 0.1225
------------------------------------
Total: 50.6275

It should go up another notch at 11pm EDT with 3 simultaneous systems contributing a fair amount of ACE at the same time.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
1726. liljade
Quoting angiest:


I don't know how long it takes there.

It would be too late now to evac Galveston and SE Houston now.
Soooooooooooo True.
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1725. leo305
Quoting Flyairbird:
just like a tornado


yea but you don't tend to see EF4 tornadoes' in a hurricane especially the eye wall..
Member Since: Posts: Comments:
OMG, What are you even thinking??? Leave now. There is absolutely no reason to stay with a Cat 4 Hurricane staring you in the face. It is not even a question? Go! You are putting yourself in the eye of potential "no way out" scenario when it will be too late. If you were inland, different story, but you are not!! Be smart..
Member Since: Posts: Comments:
After the slow start to the season are all the wishcasters happy now !!!!!!!! ??? :(
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1722. Patrap
Member Since: July 3, 2005 Posts: 423 Comments: 128240
1720. h0db
Oz sound like he's on Hatteras, approaching Buxton, NC
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1719. ADCS
Quoting 900MB:


Say what!!! 905mb? 5 more mb and it's named afetr my screen name!!!


You have to correlate it with angle. That means that where the pressure in the storm is 905 mb, there are 177 mph winds. That's not the surface pressure.
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1718. leo305
well the eye is becoming almost completely clear in infared.. a CAT 5 tends to have a completely clear eye with a perfect intense ring of monstrously strong T storms around the eye wall.. earl is developing all of that
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Quoting leo305:


a waterspout with CAT 5 winds?? in a hurricane?
just like a tornado
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1716. Levi32
Quoting hydrus:
Almost a perfect circle on the water vapor now. Here we all are witnessing one of the most powerful forces on the Earth, right in our front yard.


That's 2 hours old now. This is more recent and looks even better.

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Quoting kmanislander:


Have you looked at the latest satellite image of Earl ?. Probably not.


I am a nutt, would risk a lot...... but the imagery from Earl even scares me!

If I was on the outer banks, I would be making preparations to depart.....

Not saying I would depart, just saying I would be making preparations to do so!

But I having a feeling with the latest round of intensification, mandatory evacs will be spreading!
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Quoting TropicalAnalystwx13:




Jeez...I just don't see how he gets to 30 before 75 W...he needs to turn NOW
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Quoting VBgirl:
Rt 12 almost always washes out and gets inpassable. They usually have to get the backhoes out to get the sand off the road. Two lane road between miles of sand dunes. We're a bit better off down this end.
Then get out now. I know many others on here feel this way, but it is better to be alive and tired from driving, rather than stupid and dead.
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Quoting jeffs713:
First you say it, then you do it, then you kiss it goodbye.
Like I had posted earlier, the red cross says " put your head between your legs and kiss your butt goodbye" if you stay in that crap
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Quoting JupiterFL:


Where are the 3 drunk guys for this storm? That had to be some of the funniest video I have ever seen.


You can find Oz here:

http://thextremeweather.com/
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1708. leo305
Quoting RecordSeason:
1660:

most interesting of those is this:

944mb 142kts


that is the highest pressure among the cat5 force readings, so it implies at the surface.

It could be a water spout.


a waterspout with CAT 5 winds?? in a hurricane?
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1707. hydrus
Almost a perfect circle on the water vapor now. Here we all are witnessing one of the most powerful forces on the Earth, right in our front yard.
Member Since: September 27, 2007 Posts: 1 Comments: 21173
1706. o22sail
Quoting VBgirl:
No, wouldn't stay if I did. Just me and hubby and he's as crazy as I am.

If I were you... I'd be driving already.
Been there, done that.
Really.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.