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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dont for get it all ways take one too make it a bad year
Member Since: May 21, 2006 Posts: 5091 Comments: 115131
2455. xcool
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Quoting BaltOCane:


nice illiteration
There's nothing nice about throwing trash on the ground. doesn't matter if you can read or not.
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00z GFS is west by about 35-40 miles from the 18z run. Absolutely hammers the outer banks of NC. Very close to a landfall. Reason? Stronger ridge to the east and a sharper trough.
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The new HH is going to have to pick it up a notch to catch Earl




Member Since: October 1, 2007 Posts: 81 Comments: 26511
2451. KEEPEROFTHEGATE (Mod)
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2450. wjdow
Quoting RitaEvac:
Ever wonder if the NHC is trying to blow this, maybe so they could get more funding to get the technology they need and want. lol


no. do you?
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2449. xcool
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Quoting Amanda44:
What does it mean when you say the hurricane is becoming "annular"?
Resistant to shearing, resistant to changes in track relative to a "normal storm". Tends to create it's own environment, i.e.: not pushed around. It's core is kind of like a shield.
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This is what an annular hurricane looks like:

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Time for bed...have a good night.... leave the light on for Earl!
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Quoting NOSinger:
I guess right now really isn't the best time to ask a question about Gaston?


Unfortunately these times call for multi-tasking. Good thing is that Gaston is 120 from being a threat. Although, the LGEM has him at 117kts at that time, so, The Islands need to be well covered.

This is the year of the Male though, with the exception of Danielle. Recent past has been mostly dominated by females.
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42hrs... Jersey
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Quoting DestinJeff:
Cantore's Goggles are all doom.


Doom was when he was at the VA hospital during Katrina and swore up and down about what a great place it was to hole up, until the surge swamped his TV van.
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The East Coast water vapor image loop on NHC site shows Earl now streaking up towards the coast.
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2441. hydrus
Quoting xcool:
That looks bad.....I really hope that does not pan out.
Member Since: September 27, 2007 Posts: 1 Comments: 21256
Quoting canehater1:
Anal annular announcements are awful !
many people have been like that tonight...yes!
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2439. Ryuujin
Quoting xcool:


That's a landfall isn't it?
Member Since: August 20, 2010 Posts: 0 Comments: 373
Doesn't "annular" pretty much mean it will do what it wants (like a cut off low)?
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Quoting RitaEvac:
Ever wonder if the NHC is trying to blow this, maybe so they could get more funding to get the technology they need and want. lol
This is too wierd of a track, but I think because of the major impact either way ...Oy.
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Quoting hydrus:
Isabel in 2003 was an annular Cat-5. Google her and it should give you some info.


Thank you
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Quoting canehater1:
Anal annular announcements are awful !


nice illiteration
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Quoting BaltOCane:


pretty darn close at 30hrs


That looks like a landfall to me
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Quoting RitaEvac:
Ever wonder if the NHC is trying to blow this, maybe so they could get more funding to get the technology they need and want. lol


I heard that theory on radio tonight actually...
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Quoting hydrus:
He can have all the salt water taffy. If he will stay offshore..
Gum him up
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2430. xcool
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Winds: SSE (160°) at 44.7 kt gusting to 54.4 kt
Significant Wave Height: 29.2 ft

I wonder if there is white caps with those?
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30hrs.

pretty darn close
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The CV train has been running without a break for a long time know. What I like to know is when should be see the caboose? Or in other words when is the Cape Verde season normally end?
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2426. hydrus
Quoting ShenValleyFlyFish:
Maybe some saltwater taffy.
He can have all the salt water taffy. If he will stay offshore..
Member Since: September 27, 2007 Posts: 1 Comments: 21256
Blog is broken...
Member Since: April 26, 2009 Posts: 3 Comments: 3667
2424. Ryuujin
Quoting Orcasystems:




Wow...
Member Since: August 20, 2010 Posts: 0 Comments: 373
Quoting Beachfoxx:
Dang, Orca, if Rocky ends up back in my house...... I know who to blame! ROFL


You miss Rocky.. life was so interesting for a couple days :)
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Quoting hydrus:
Africa.....Says he wants a souvenir from the good ole U.S of A. Dont know if he wants Carolina Crab Cakes or some New England Clam Chowder or both.

LOL! Hilarious!
This one seems to be quite tricky. Sitting in Raleigh being told not to worry. I always worry when I'm told not to worry. The worst storms are always the ones that no one expects to do anything.
Hopefully this is not the case this time. I'm 95% sure it will spin off just as predicted. :)
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Quoting medic11402:
I think the overall message is this, the NHC said in there public advisory at 11pm NOT TO FOCUS ON THE TRACK... Unless Earl went to school, He is not reading the NHC Track map following through. The NHC took the line out of there map to prevent people from focusing on the "PATH", they would much rather that you focus on the cone and pay attention to your local Emergency Management Agency. Hurricane forecasting with the scientific study and data still has an element of art to it. Preparedness means paying attention, heeding the warnings and responding appropriately. If you live on the East Coast, let me clue you in, there is a threat to your area. FEMA has already begun positioning people and supplies for a possible response. Anyone know why they are doing that, because there is enough concern with Hurricane Earl that it may impact the East Coast. The bottom line is this, ARE YOU READY? DO YOU HAVE A PLAN? WHAT IS YOUR LIFE WORTH? if the NHC is right, then so bi it and you have just had an opportunity to exercise your plan. If the NHC is off, then you are going to be well ahead of the curve by executing your plan when the local Emergency Management Agency alerts you to the threat. If you do not have a plan IT IS TIME TO MAKE ONE AND BE PREPARED TO INITIATE IT, it may just save your life.....
The wind field is huge 230 Mi.....
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Test.
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pretty darn close at 30hrs
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I guess right now really isn't the best time to ask a question about Gaston?
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Ts,yea im signed in,or was at the time,i'll try again.......looks like tomorrow should we should know with more confidence if a major will make landfall in nc/sc?????
Member Since: October 5, 2007 Posts: 20 Comments: 4970
.
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Ever wonder if the NHC is trying to blow this, maybe so they could get more funding to get the technology they need and want. lol
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2414. Ryuujin
Quoting Orcasystems:


I must admit.. I can't tell them apart anymore... they all look the same :(



All Hail the Hypnotoad!!
Member Since: August 20, 2010 Posts: 0 Comments: 373
Quoting oracle28:


Yes and a post-Cat5 will have had (at some point)stronger winds to push water in its path than a Cat3 storm that never reached 145mph in its lifetime.
Watch the presentation in my link.

What happens in deep water, including peak wind speed and central pressure, doesn't make it to shore in the surge. Conditions of the storm at landfall have 99% to do with the surge that we actually experience.
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Quoting hydrus:
Africa.....Says he wants a souvenir from the good ole U.S of A. Dont know if he wants Carolina Crab Cakes or some New England Clam Chowder or both.
Maybe some saltwater taffy.
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Well I'm going to bed. I took the rest of the week off, so I can watch Earl until my heart's content.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
2410. hydrus
Quoting Amanda44:
What does it mean when you say the hurricane is becoming "annular"?
Isabel in 2003 was an annular Cat-5. Google her and it should give you some info.
Member Since: September 27, 2007 Posts: 1 Comments: 21256
So close, but it looks like a miss:

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Wow! I'm at 68 degrees right now, humidity 67%. First time out of the 70s at night since June. I just want to stand under the stars 'till dawn.
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Dang, Orca, if Rocky ends up back in my house...... I know who to blame! ROFL
Quoting Orcasystems:


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Quoting hydrus:
Africa.....Says he wants a souvenir from the good ole U.S of A. Dont know if he wants Carolina Crab Cakes or some New England Clam Chowder or both.
Maybe some saltwater taffy.
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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.