Disturbance 91L spins towards Cape Hatteras; Cyclone Aila toll at 180

By: Dr. Jeff Masters , 1:28 PM GMT on May 27, 2009

Share this Blog
2
+

An area of disturbed weather, dubbed "91L" by the National Hurricane Center, is centered 120 miles south of Cape Hatteras, North Carolina. While the storm does not have much in the way of heavy thunderstorm activity, it does have a well-developed circulation, and the spin of the system is readily apparent on long range radar animations out of Morehead City, North Carolina. The disturbance is over waters of 25 - 26°C and has wind shear of 10 - 15 knots over it, and these conditions are marginally favorable for some slow development to occur until Thursday afternoon, when the system will begin moving over waters too cold to support tropical cyclone development. The disturbance will track north or north-northeastward at 10 - 15 mph towards North Carolina's Outer Banks today, then get swept northeastwards out to sea on Thursday. It is unlikely that the disturbance has enough time to develop into a tropical depression, but an Air Force hurricane hunter flight is on call to investigate the system this afternoon, if necessary. If the system does develop, the current location of the heaviest thunderstorm activity in a band well removed from the center suggests that 91L would be classified as a subtropical depression. The Outer Banks of North Carolina can expect 20 - 25 mph winds and heavy rain from this system tonight and Thursday morning. In a Special Tropical Weather Outlook issued at 8am EDT this morning, NHC gave 91L a low (less than 30% chance) of developing into a tropical depression.


Figure 1. Latest radar image from the Morehead City, NC radar.

Tropical Cyclone Aila death toll at 180
The year's deadliest tropical cyclone so far, Tropical Cyclone Aila, has killed at least 180 people in India and Bangladesh border region, according to the latest media reports. Aila hit the India/Bangladesh border region on May 25 as a borderline tropical storm/Category 1 hurricane, bringing sustained winds of 65 - 75 mph and a 3 - 4 meter (10 - 13 foot) storm surge to the coast. Aila has left over 150,000 homeless in India and 500,000 in Bangladesh. The cyclone destroyed over 180,000 homes in Bangladesh--a severe blow for a region still recovering from the devastation wrought by Category 4 Tropical Cyclone Sidr of November 2007, which killed 3,500 people. The death toll form Aila will likely go much higher, as over 500 people are still missing. The Bay of Bengal is no stranger to deadly cyclones--fifteen of the world's twenty deadliest tropical cyclones have been Bay of Bengal storms that have hit Bangladesh, India, or Myanmar. The most recent was last year's Cyclone Nargis, which killed 146,000 people in Myanmar.


Figure 2. Satellite image of Aila as it made landfall near the India/Bangladesh border. Image credit: NASA.

Interview tonight on hurricanetrack.com
I'll be doing one of my periodic spiels on Internet radio tonight at 9pm EDT. Tune your browsers to www.hurricanetrack.com and listen in to my interview with host Mark Sudduth. There is also a live chat to participate in. Hurricane season starts Monday!

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: 145 - 95

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11Blog Index

Quoting StSimonsIslandGAGuy:
Rain for Canewarning :) Storms this week have been missing or dying before they reach me, but after 7.77" last week we are fine :)


No, I think we've had enough rain in Florida! It's funny how quickly things can change. A couple of weeks ago we'd beg for rain.
Member Since: Posts: Comments:
143. 7544
looks like most are saying here that once it gets it the gom the texas blob will gett ripped apart by shear but some models show it as a system heading to the se then east whos right we have wait and see tonight i guesss could this become 92l first ?
Member Since: May 6, 2007 Posts: 0 Comments: 6690
Quoting tornadofan:


Yep - the scattered high clouds left over when it falls apart may result in a stunning sunrise or sunset!


Very Funny...Lol
Member Since: Posts: Comments:
Quoting Landlock:
Texas Blob is looking very serious in the latest imagery. Everyone living along the gulf coast needs to keep a watchful eye on it in the coming days.


Yep - the scattered high clouds left over when it falls apart may result in a stunning sunrise or sunset!
Member Since: Posts: Comments:
Texas Blob is looking very serious in the latest imagery. Everyone living along the gulf coast needs to keep a watchful eye on it in the coming days.
Member Since: Posts: Comments:
Updated the TEXAS BLOB & 91.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Quoting SomeRandomTexan:
This blob coming off of Texas is in my belief just upper level diffluence following the front.

Doubt it will form anything, except maybe subtropical... conditions aren't favorable in the GOM right now... shear is high and SST's have been lowered due to 90L and the last front.


Forecast surface trough now with our little Texan Blob.
Member Since: Posts: Comments:
Quoting StormFreakyisher:
This is fun watching blob after blob. When one goes away another blob appears.Just wait until we get to September haa!


I like your enthusiasm. :)
Member Since: Posts: Comments:
This is fun watching blob after blob. When one goes away another blob appears.Just wait until we get to September haa!
Member Since: Posts: Comments:
This blob coming off of Texas is in my belief just upper level diffluence following the front.

Doubt it will form anything, except maybe subtropical... conditions aren't favorable in the GOM right now... shear is high and SST's have been lowered due to 90L and the last front.
Member Since: Posts: Comments:
Quoting presslord:
nice Cane!


That sure looks like a Texas blob to me... I wonder what it is.
Member Since: Posts: Comments:
nice Cane!
Member Since: Posts: Comments:
What a dreary day here in eastern NC....
Member Since: Posts: Comments:
Quoting presslord:
Texas Blob...sounds like a country music band...


True.. or something they would BBQ
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Quoting presslord:
Texas Blob...sounds like a country music band...


This is what came up when I Google Texas blob images.

Link
Member Since: Posts: Comments:
Texas Blob...sounds like a country music band...
Member Since: Posts: Comments:
The final test of the live webcam and remote hurricane weather station is progressing nicely. The test will end at approximately 8 PM MDT...so you still have time to see the birds, how fast they move...and how this system captures it all.

The system has been stable all day long with only a small and expected hiccup early on this morning.

Since then, we've had uninterrupted streaming of live video with amazing frame rates [29.97 max - 29.89 avg.]

It has been a pleasure putting this system together for you all.

When it fires back up, it will be in an area projected for a hurricane landfall.

CycloneOz---
Member Since: Posts: Comments:
That Texas Blob is getting some attitude.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
please check out the Portlight Blog...
Member Since: Posts: Comments:


AOI #1

AOI #2
Member Since: October 1, 2007 Posts: 81 Comments: 26511
124. 7544
Quoting StormFreakyisher:
Wow it dodges Florida completely and goes around it.Lets see if that actually happens.


not on this run
Link
Member Since: May 6, 2007 Posts: 0 Comments: 6690
Wow it dodges Florida completely and goes around it.Lets see if that actually happens.
Member Since: Posts: Comments:
Quoting CaneWarning:


Rainmaker if anything.


Hope it stays over water. Houston radar. Had 3+ inches today here in Pensacola and some NASTY lightning. Something got hit nearby. Heard fire trucks and smelled like burnt electrical.
Member Since: Posts: Comments:
Quoting Orcasystems:


Disturbance 91L spins towards Cape Hatteras; Cyclone Aila toll at 180

I will leave it at that.. I won't compare the numbers to what (some) Americans call a devestating Hurricane that hits the USA.
Yes but I was meaning a storm that would make the headlines of lots of news Sources so anyone who follows the news would be well aware of it
Member Since: Posts: Comments:
Quoting Ossqss:



12Z version.


That version has it much more to the south.
Member Since: Posts: Comments:



12Z version.
Member Since: Posts: Comments:
Quoting StormFreakyisher:
Do any of you think the blob off the Taxas coast will be an invest or just a rain maker for Florida.There is 40knt shear across Gulf of Mexico.Any chance it will calm down?


Rainmaker if anything.
Member Since: Posts: Comments:
Do any of you think the blob off the Taxas coast will be an invest or just a rain maker for Florida.There is 40knt shear across Gulf of Mexico.Any chance it will calm down?
Member Since: Posts: Comments:
Quoting WPBHurricane05:
Crazy weather at my house- Link

25+ MPH winds.


That's one nasty cell in WPB


In the extreme catagory
Member Since: Posts: Comments:
Crazy weather at my house- Link

25+ MPH winds.
Member Since: Posts: Comments:
This would be where I am...my community is right next to Whisper Walk literally!
THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR... SOUTHEASTERN PALM BEACH COUNTY IN SOUTH FLORIDA.

* UNTIL 345 PM EDT

* AT 306 PM EDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL... AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR WHISPER WALK... AND MOVING NORTHEAST AT 15 MPH.

* THE STORM WILL AFFECT... BOCA RATON... DELRAY BEACH... VILLAGE OF GOLF... BOYNTON BEACH... AND SURROUNDING COMMUNITIES.

REPORT SEVERE WEATHER OR DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY EMERGENCY MANAGEMENT. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN MIAMI. OR YOU CAN ALSO CALL THE NATIONAL WEATHER SERVICE IN MIAMI DIRECTLY AT 305.229.4528 TO REPORT SEVERE WEATHER.

Member Since: Posts: Comments:
Quoting Chicklit:
Okay Cane, I guess that bears watching then, thanks.


Could get rather sloppy in FL if we get another rain storm.
Member Since: Posts: Comments:
WOW look at the miami radar talk about pop up T-Storms
Member Since: Posts: Comments:
Good afternoon,

Portlight Strategies, Inc. is currently preparing to respond to the recent flooding in Volusia County. Please learn how you can help!
Member Since: Posts: Comments:
We don't need any more rain in Florida.
Member Since: Posts: Comments:
Okay Cane, I guess that bears watching then, thanks.
Member Since: Posts: Comments:
Quoting Chicklit:
Good afternoon.
Looks like 40 knots of shear in the Gulf.Link


The GFS blip is frontal, maybe Extra-Tropical and less impacted by shear. A lot of rain and a little wind.
Member Since: Posts: Comments:
Quoting DestinJeff:


the blog just isn't active enough to get the typical response. sorry.


I wasn't trying to get a response. Just stating a fact.
Member Since: Posts: Comments:
I keep a bookmark to NOAA's list of Meteorology terms for personal reference. It's a very extensive list and is very beneficial, especially for those trying to learn more about the subject.

Meteorology Terms
Member Since: Posts: Comments:
Good afternoon.
Looks like 40 knots of shear in the Gulf.Link
Member Since: Posts: Comments:
Quoting 7544:


hmm check it out could become and 92l
look where it could be heading
Link


It looks like its coming to Tampa to me.
Member Since: Posts: Comments:
101. 7544
Quoting WPBHurricane05:
Seeing that it is unlikely that 91L will form, its back to blob watching.



hmm check it out could become and 92l
look where it could be heading
Link
Member Since: May 6, 2007 Posts: 0 Comments: 6690
Quoting Weather456:


There is a fundamental difference in the orientation of the flow.





Right again, so hard to keep vocabulary straight in my head. One of my stupid books tried to say they were the same thing too lol. Sorry guys my bad.

Divergence is caused by air speeding up or pulling apart in opposite directions, and therefore spreading out. Diffluence is air spreading out when the air stream (contours) spread out, like in 456's image. Convergence and Confluence are the opposites.
Member Since: November 24, 2005 Posts: 635 Comments: 26547
Thanks Levi & 456.....Yall are too cool and I greatly appreciate the nice tutorial..WW
Member Since: Posts: Comments:
Quoting Levi32:


Lol I know I've had to use that explanation for at least 4 blobs now in the last week. Those two terms really aren't that complicated.

Divergence basically is "spreading out of air"

Convergence basically is "piling up of air"

See? Pretty simple lol. For most of these blobs I'm talking about upper-level divergence. You can translate that into "spreading out of air in the upper levels". When you think about that, if air is spreading out up there, then new air needs to come in to replace it. The only place it can come from is below, so air at the lower levels rises up to replace the air spreading out at the top. And we all know that when air rises it condenses into clouds and if strong enough, thunderstorms, such as the ones over SE Texas right now.

BTW "diffluence" is another term used synonymously with "divergence", and similarly "confluence" and "convergence" basically mean the same thing.


There is a fundamental difference in the orientation of the flow.



Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting WPBHurricane05:
Seeing that it is unlikely that 91L will form, its back to blob watching.



Looking like another rainy weekend coming up for us. I have to admit the mood in the house over this past weekend was rather tired and unmotivated after last week. It's amazing how much we depend on our sunshine here, lol.
Member Since: Posts: Comments:
BBL,

Tropical Update
Member Since: July 24, 2005 Posts: 407 Comments: 19076

Viewing: 145 - 95

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11Blog 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
67 °F
Overcast