Earl a Category 4 storm again

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

Share this Blog
2
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 2656 - 2606

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59Blog Index

Just did a blog on the very active tropics. Have a look!
Member Since: March 7, 2007 Posts: 553 Comments: 19890
This could be the "It could happen tomorrow" storm for NYC!!
Member Since: Posts: Comments:
2654. xcool


As always, remember 300hr out but every run will change between now and next time.
Member Since: September 26, 2009 Posts: 2 Comments: 15620
2653. mkmand
Which will Earl pass first?

30N or 75W?
Member Since: Posts: Comments:
2652. Acorna
I am not an expert but I think it's too early to predict where Gaston will ultimately go - he's too far out.
Member Since: Posts: Comments:
Quoting F4PHANTOM:
starting to pull north
I really hope that it does not pull an Ike with Galveston and Houston. I was without light for 3weeks.
Member Since: Posts: Comments:
2650. JLPR2
Quoting traumaboyy:


Mornin JLPR2!


It's more like night to me. XD
Hiya!
Member Since: Posts: Comments:
2649. dmaddox
Quoting dmaddox:
rapid scan Goes-15 IR: Link
NW eyewall not lookin so hot...
Member Since: Posts: Comments:
Quoting LAlurker:

Invite your Jersey shore family to come to your place - soon.


Your family will be fine man. Won't be worse then a bad Nor'easter beacuse you'll be on the weaker side of the storm..
Member Since: Posts: Comments:
Northern portions of SC (Myrtle beach) are not even under TS watches and they could definitely feel TS force wind if it stays on present course. Supposed to turn at 75W and 30 N...will seeeee
Member Since: Posts: Comments:
Quoting JLPR2:


Look at Igor(the feared one) off the coast of Africa there. XD


Mornin JLPR2!
Member Since: Posts: Comments:
Quoting weatherdogg:
"Why is earl's west side bowing out like that??"

That's what I keep asking, but no one is listening.


Earl is starting to feel the trough, IMO. Click the image for full size.

Member Since: Posts: Comments:
2644. dmaddox
rapid scan Goes-15 IR: Link
Member Since: Posts: Comments:
Quoting smuldy:
not quite here yet but a quick hello to the night crew; the answer is dry air, likely won't last too long


Hiya Smuldy!! Coffee is ready!!

Member Since: Posts: Comments:
2641. JLPR2
Quoting xcool:


okay now i wait


Look at Igor(the feared one) off the coast of Africa there. XD
Member Since: Posts: Comments:
Quoting NJ2S:


i know it is not im just asking in a almost worst case scenario if it happens to be closer than expected im hoping the local mets are right and we just get some breezy showers....ive never been through hurricane and have family livin at the jersey shore so thats why i ask....dont mean to speculate or westcast or watever :)

Invite your Jersey shore family to come to your place - soon.
Member Since: Posts: Comments:



Member Since: Posts: Comments:
2637. KEEPEROFTHEGATE (Mod)
2594

thats up too earl
Member Since: July 15, 2006 Posts: 169 Comments: 53296
Quoting robj144:


From the link Link:

"The storm surge is an abnormal rise in sealevel due to two effects. First, a minor effect is the fact that the very low pressure at the center of hurricanes causes an upward bulge in the ocean at the center of the storm. Thus, the ocean levels are higher there than in the surrounding areas, often by a matter of 5 feet or so.

In addition, the major effect has to do with the augmented winds on the right forward margin of the storm physically pushing the ocean against the coastline for a storm moving from southeast to northwest. The combination of these two effects makes, in particular, the forward right quadrant of a hurricane very prone to significant storm surges, sometimes of nearly 25 feet or so."

I think you need to go back to school... :)


I am happy to have gained this knowledge. Thanks all. This is clearly why I became a geologist. No one can question what I say about the rocks 5,000 feet below my feet!
Member Since: Posts: Comments:
2635. wjdow
Quoting thelmores:


REALLY?

What loop are you looking at?

Earl even in the latest frames available has a significant westward component..... and has made it all the way to 74W......

maybe you better look again! Link



why bold?
Member Since: Posts: Comments:
chaos, damage, skyscraper windows busted out, news media going nuts, breaking news on 24/7
Member Since: Posts: Comments:
I think Earl is going to be a very close call... more likely just rain and some tropical storm wind around the East Cost. In the other hand Gaston has the potential to be a very dangerous storm for the Gulf Cost.
Member Since: Posts: Comments:
2632. NJ2S
Quoting 1900hurricane:
GOES-15:



dry air getting in?
Member Since: Posts: Comments:
And Dr. M's take on surge from a small storm, Camille (not unlike Charley) and a large storm, Katrina.
http://www.wunderground.com/hurricane/surge_details.asp
(references Fitzpatrick, too)
Member Since: Posts: Comments:
2629. xcool


okay now i wait
Member Since: September 26, 2009 Posts: 2 Comments: 15620
It's obviously going mostly north.


REALLY?

What loop are you looking at?

Earl even in the latest frames available has a significant westward component..... and has made it all the way to 74W......

maybe you better look again! Link

Member Since: Posts: Comments:
2626. leo305
Quoting NJ2S:
0ij0j

lol....oh i get it...yikes, the city and surrounding area would be completely caught off guard....its been wobbling since b4 the leeward islands so its hard to tell if that northward turn is becoming sharper


it has become sharper, since the antilles but.. the NW movement its been doing since the Bahamas hasn't changed.. which is dangerous, it jogged North for a couple of hours earlier today and everyone thought it was finally turning, then it got stronger and starting moving NW again.. the more west it gets the stronger the impact will be along the east coast of the US
Member Since: April 17, 2010 Posts: 0 Comments: 1753
2625. dmaddox
Quoting 1900hurricane:
GOES-15:

N of 28 now.. hmm... speeding up IMO...
Member Since: Posts: Comments:
2624. xcool
F4PHANTOM You Never Know :)~~~
Member Since: September 26, 2009 Posts: 2 Comments: 15620
Norcross is good!! We can do without all the drama queens on the Cape's!
Member Since: Posts: Comments:
2622. smuldy
Quoting weatherdogg:
"Why is earl's west side bowing out like that??"

That's what I keep asking, but no one is listening.
not quite here yet but a quick hello to the night crew; the answer is dry air, likely won't last too long
Member Since: Posts: Comments:
2620. KEEPEROFTHEGATE (Mod)
Member Since: July 15, 2006 Posts: 169 Comments: 53296
2619. NJ2S
0ij0j
Quoting leo305:


No =P, I meant his map wasn't with the center being 50 miles away.

If the eye is 50 miles east of new york, you could get hurricane force winds.


lol....oh i get it...yikes, the city and surrounding area would be completely caught off guard....its been wobbling since b4 the leeward islands so its hard to tell if that northward turn is becoming sharper
Member Since: Posts: Comments:
Quoting oracle28:


No, just based on previous Cat 4 storms. Never did I mention a scale.

????
Member Since: Posts: Comments:
GOES-15:

Member Since: Posts: Comments:
2614. xcool


TexasHurricane .not going out sea
Member Since: September 26, 2009 Posts: 2 Comments: 15620
Quoting presslord:


we shouldn't be...we're not even gonna know it's out there ..


Let's hope your right!!
Member Since: Posts: Comments:
Quoting oracle28:


Also a common phrase is "you can't cure stupid"


and..."you can't sheath a chainsaw"
-obscure Bruce Dern quote seemed appropriate considering Earl's strength...
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting atmoaggie:
That I am.

What to see the Karina surge modeling results with wind overlaid on surge contours? http://www.nd.edu/~adcirc/katrina.htm

Pretty evident there.

Oh, and one final point. Of Katrina's surge, highest on the MS gulf coast, the top ~4 feet have everything to do with the shape of the shoreline. That water would have escaped to the west, if it could. But LA is in the way. (As if the Ole Miss/LSU game needed to be bigger)

WHOOP (and before anyone jumps at me, I have ZPs)!!!
Member Since: Posts: Comments:
2609. KEEPEROFTHEGATE (Mod)
Member Since: July 15, 2006 Posts: 169 Comments: 53296
Quoting xcool:

Is that as far the models show on Gaston. Can you show the last frame for that model
Member Since: Posts: Comments:
Good to see you around press!!,even at this late hr;)
Member Since: Posts: Comments:
GETTIN CLOSER
Member Since: Posts: Comments:

Viewing: 2656 - 2606

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Overcast
70 °F
Overcast