Isaac approaching hurricane strength

By: Angela Fritz , 9:14 PM GMT on August 27, 2012

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Isaac is walking the line of hurricane status this afternoon after a hurricane hunter mission investigated the storm and found winds of 80+ mph with the SFMR instrument, which looks down at the surface from the plane and estimates what wind speeds are. This instrument has a notoriously rough time in doing so when there's heavy rain, and since the strongest winds were recorded coinciding with the strongest rain, you can imagine that this region of high wind speed could be suspect. The hurricane hunter mission is still in the storm, so I imagine they will issue a special update if needed. Currently the best estimate of wind speed within the storm is 70 mph. Isaac's pressure has been dropping today as well and is now 981 mb. Isaac is moving northwest at 12 mph--no change since this morning. Satellite loops show that Isaac remains large, though asymmetric, with most of the strong thunderstorm activity on the west and southwest side. Isaac's southeast side continues to struggle with dry air and wind shear, which could help to moderate Isaac's intensity as it approaches the coast.

An oil platform in the northern Gulf of Mexico is reporting sustained winds from the north-northeast at 40 mph this afternoon. A buoy west of Tampa, Florida is recording sustained winds around 30 mph, and platforms south of Louisiana are recording winds from 35-40 mph. The widespread heavy rain of yesterday has lightened up in Florida, but a strong line of thunderstorms in one of Isaac's outer bands is training northward along and offshore of the east coast of Florida, affecting everyone from Miami to Jacksonville.

This afternoon the AP reported that Isaac's death toll in Haiti jumped to 19, which puts Isaac's total death count at 21. It appears most of the deaths in Haiti were due to collapsing structures.


Figure 1. Satellite imagery of Tropical Storm Isaac around 3pm EDT on Monday.

Track forecast:
Models seem to be coming into better agreement today on where Isaac will make landfall, closing in on Louisiana and New Orleans as most likely landfall point. The ECMWF, HWRF, and UKMET all suggest New Orleans as the landfall location. The GFS is only slightly west of that. The GFDL is the farthest west, predicting landfall near the Louisiana-Texas border. Landfall timing remains Tuesday night. Beyond landfall, Isaac is expected to move north toward the Midwest through the rest of this week, however, models are showing that the system will likely slow down around landfall time, prolonging impacts like surge and inland flooding.

Intensity forecast:
The closer Isaac gets to landfall without having formed an eye, the better it is for intensity at landfall. Isaac has strengthened only modestly in the past 24 hours, and is still struggling with a less-than-conducive atmospheric environment. The HWRF remains on the high end of the intensity spectrum, suggesting Isaac will be a weak category 2 upon landfall. Other models suggest it will be a strong category 1, but the difference is splitting hairs. The National Hurricane Center's official forecast is for Isaac to continue strengthening over the next day, reaching category 2 at landfall.


Figure 2. Tide gauge data from St. Petersburg, Florida. The green line shows the storm surge. As Isaac's counterclockwise winds blew offshore this morning, water levels feel two feet at St. Petersburg. The winds switched to onshore this afternoon as the center of Isaac moved more to the northwest, bringing a storm surge of two feet to the city.

Storm surge observations from Isaac
This morning, as Isaac's counter-clockwise winds brought offshore winds to the Tampa/St. Petersburg area, ocean waters fell two feet along the coast. This afternoon, winds have shifted to blow onshore, and a two foot storm surge has been observed at Naples, Fort Meyers, and St. Petersburg on the west coast of Florida. Water levels have also begun to rise along the coast of Louisiana, with a storm surge of 1.5 feet already occurring at Shell Beach on the east side of New Orleans in Lake Borgne.

Angela and Jeff

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Quoting Chicklit:

Otherwise Isaac will be a big wet sloppy mess cruising into a Gulf coastal area and hanging around for days. What is worse?
I know. Sometimes the tropical storms that just hang for days cause the most damage.
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Quoting Walnut:
With Firefox and Ghostery I get no ads at all.


With a paid subscription to support the site, I get no ads. ;-)
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Quoting HurricaneHunterJoe:
Im now watching New Orleans Coverage of Isaac. Thanks to whoever posted the Direct TV having the coverage on Channels 325 and 349.


You are very welcome!!!
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Quoting Chicklit:

Otherwise Isaac will be a big wet sloppy mess cruising into a Gulf coastal area and hanging around for days. What is worse?


Exactly.
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1150. sar2401
Quoting NEPASteve:
I just got on.  Is Isaac a Hurricane?  Also didn't I read earlier he wasn't going to get past 85W?


Not a hurricane. He wasn't supposed to do a lot of things, including getting past 85W. So much for guessing.
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1149. Walnut
Quoting avthunder:
Really? I get ads for puppies and rainbows.
With Firefox and Ghostery I get no ads at all.
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1148. airmet3
Quoting wilburo33:
This storm appears to be weaker based on the radar image...


The center is right on the edge of the Northwest Florida radar. Not sure which radar you are using.

NW Florida is shooting through the dry air on the north side, but the mid level circulation is there and has at least some scattered convection.
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Outer rain bands showing up on Mobile Radar

Link
Member Since: September 8, 2008 Posts: 1 Comments: 1078
Quoting MAweatherboy1:


Best site out there.


Thank you so much!!
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Hurricane at 11pm?
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Quoting CybrTeddy:


Per NHC, Isaac has 36 hours over water. Has enough time to become a Category 1.


Not out of the realm of possibility, but he's looking pretty shabby around the margins. If he stalled out for 12 hours or so, maybe, but he hasn't had very good organization since, well, forever.
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1143. sar2401
Quoting CaicosRetiredSailor:
Isaac Claims Containership in Cuban Waters

BY ROB ALMEIDA ON AUGUST 27, 2012

Mariners in the Gulf of Mexico region reported to us today of a continual alert being received over distress frequencies off Cuba, one that we have been able to track back to the Hansa Berlin, a 19 year-old Liberian-flagged containership owned by Leonhardt & Blumberg.

The US Coast Guard confirmed that the Liberian-flagged vessel has run aground and that Cuban authorities are currently in charge of the situation. �No reports are yet available on the status of the crew or vessel.

An unconfirmed report places the vessel approximately 30 miles west of Havana, however we have not yet been able to independently confirm this.

http://gcaptain.com/isaac-claims-containership-cu ban/


And we know a junker interisland container ship grounding was caused by Isaac how?
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I just got on.  Is Isaac a Hurricane?  Also didn't I read earlier he wasn't going to get past 85W?
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1141. SirCane
Mississippi Landfall... Models showing that now.
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Quoting azduck:
If Isaac was going to intensify, he needed to do so today. Looks like we have a minimal cane/strong TS at landfall, biggest risk is a rainmaker a la Claudette or Allison. In New Orleans, that is no joke.

Does he have an eye? Probably, but who cares, he's coming up on the continental shelf and is out of time to do anything as far as significant strengthening goes.


Waters are plenty warm all the way up to landfall.
Member Since: July 6, 2010 Posts: 113 Comments: 32338
Quoting GetReal:



Isaac has ONE more chance and that is DMAX tonight. That will be his LAST chance...

Otherwise Isaac will be a big wet sloppy mess cruising into a Gulf coastal area at or near New Orleans and hanging around for days.
What is worse?
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Quoting weatherh98:


Walgreens s everything u need, nobody thinks to go there


LOL, they did remember here! But you're right, they generally do forget about Walgreens! Very small town here, only two grocery stores, so we all know the other spots in town.
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Quoting bballerf50:
Hello All. Can one of you fine bloggers please post the best link for the long range GFS and others? Thanks


Best site out there.
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1st post, after using this site for years.

The comments section has degraded to the embarrassing.

Chem trails? US military "dropping" something in the NE quadrant? Bizarro wishcasting for some Katrina-like megastorm, which drowned 2000 people (aka- 2000 people screaming/praying for Jesus and their mothers as they sank into 20 feet of muck-water) and destroyed an entire American city?

What is wrong with you people?

The fact is this *Tropical Storm*(as a hypothetical circle) has 1/3 healthy band activity but is half-surrounded by such dry air that simple cirrus clouds can barely form in these areas- much less thunderstorms. The storm just quaffed a bunch of this dry air into its core, which shut down convection again.

Powerful cyclones (>Cat3 at landfall) which destroy families and communities are incredibly rare- because the conditions required to support these storms almost never happen together. Nationally, maybe once or twice a generation. So stop thinking that every tropical depression that enters the Gulf is Katrina 2.0.

Bottom line: enough with the embarrassing and insulting comments.
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Quoting Chicklit:
It would be really awful if the blob off the east coast turned around and headed back to south Florida.
Link WV Loop


If you look down by Cuba you see blob bits going southwest through. Crazy.
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Im now watching New Orleans Coverage of Isaac. Thanks to whoever posted the Direct TV having the coverage on Channels 325 and 349.
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1132. GetReal
Quoting azduck:
If Isaac was going to intensify, he needed to do so today. Looks like we have a minimal cane/strong TS at landfall, biggest risk is a rainmaker a la Claudette or Allison. In New Orleans, that is no joke.

Does he have an eye? Probably, but who cares, he's coming up on the continental shelf and is out of time to do anything as far as significant strengthening goes.




Isaac has ONE more chance and that is DMAX tonight. That will be his LAST chance...
Member Since: July 4, 2005 Posts: 204 Comments: 8898
Hello All. Can one of you fine bloggers please post the best link for the long range GFS and others? Thanks
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Quoting aislinnpaps:

If people enjoy and use the blog, really, is ten dollars too much to pay to support it?

Walmarts and other stores here are out of water, bread, batteries, flashlights, etc..



Walgreens s everything u need, nobody thinks to go there
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Quoting TomballTXPride:

For a weather blog, yes. I'll pass. But I'll still enjoy it too. Win-Win.


Sad
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Burst of convection on the north side is a very positive thing for the storm, negative for us
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1126. Grothar
Quoting HCW:


Would you like a code so you have have a free year of WU with no ads ?


Yes, I'll give you $10 for it.
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It would be really awful if the blob off the east coast turned around and headed back to south Florida.
Link WV Loop
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1124. sar2401
Quoting HCW:


I will you can donate the money to Portlight for me :) If you have watched the TVCN line for the last 2 storms The NHC has always moved the official track in 1 or 2 advisorys to match it


OK, will do. The TVCN line may be the current NHC line but I still think Isaac is going more west than forecast, as he has been almost since the begining. We'll see who's right. Either way, Portlight gets $10. :)
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Is it tending to pull north? very elongated system.
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1121. azduck
If Isaac was going to intensify, he needed to do so today. Looks like we have a minimal cane/strong TS at landfall, biggest risk is a rainmaker a la Claudette or Allison. In New Orleans, that is no joke.

Does he have an eye? Probably, but who cares, he's coming up on the continental shelf and is out of time to do anything as far as significant strengthening goes.

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Quoting LAnovice:

Really ??? - posting quiz bowl is highly insensitive for the folks that are dealing with the storm and its potential landfall. Please take your games elsewhere when folks are interested in serious discussion about weather which may affect their lifes and those of their children.
On a less critical time - go have at it.

Ok - this wasn't directed to you - only the post to which you responded.
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Well with the slow pace Isaac is moving, the EWRC ongoing, and an eye forming, it's very well possible for it to ramp up if it clears out that dry air in its eastern quad. The SSTs are 83-85F, which is plenty enough for rapid intensification even at 36 hours out from potential landfall. The question is will it organize itself to do it. I'm going with a strong Cat1/weak Cat2 at the most.
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Quoting sunlinepr:


Someone please post an animated Gif proving it....

Really ??? - posting quiz bowl is highly insensitive for the folks that are dealing with the storm and its potential landfall. Please take your games elsewhere when folks are interested in serious discussion about weather which may affect their lifes and those of their children.
On a less critical time - go have at it.
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If people enjoy and use the blog, really, is ten dollars too much to pay to support it?

Walmarts and other stores here are out of water, bread, batteries, flashlights, etc..

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Isaac Claims Containership in Cuban Waters

BY ROB ALMEIDA ON AUGUST 27, 2012

Mariners in the Gulf of Mexico region reported to us today of a continual alert being received over distress frequencies off Cuba, one that we have been able to track back to the Hansa Berlin, a 19 year-old Liberian-flagged containership owned by Leonhardt & Blumberg.

The US Coast Guard confirmed that the Liberian-flagged vessel has run aground and that Cuban authorities are currently in charge of the situation. No reports are yet available on the status of the crew or vessel.

An unconfirmed report places the vessel approximately 30 miles west of Havana, however we have not yet been able to independently confirm this.

http://gcaptain.com/isaac-claims-containership-cu ban/
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Quoting TomballTXPride:


Poll?

A) Dry air

B) Eye
If it was a dry slot it was in the perfect spot to fool us. Its an eye. Very early developed one that will soon be covered by a CDO.
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Quoting GetReal:
Eye is in radar range.



I don't see that getting west of New Orleans, but I'm no expert...just observing. Thanks for gif!
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1112. Caner
Quoting HCW:


Would you like a code so you have have a free year of WU with no ads ?


i have one ;)

Link
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Quoting Pcolanyc:


Last comment on this: the advertisements you see on any website other than very specific politcal sites are determined by the ads paid for and your own cookies. Since it is an election year, you are seeing many political ads. These ads are probably not bought from a particular site, but from an agent that has a portfolio of sites. There is no reason to think anyone on the site is critical of your own dearly held political beliefs.

I look forward to learning more about weather in the future.

thats a bunch of bull, since the only lib site I frequent is this and all I get is Obama stuff.
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This storm appears to be weaker based on the radar image...
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Quoting CybrTeddy:


Per NHC, Isaac has 36 hours over water. Has enough time to become a Category 1.



That is enough time for him to become a cat 3 if he wanted
Member Since: August 1, 2006 Posts: 28 Comments: 3716
Quoting slavicthunder:
♫ ♫♫♫

"EYE! EYE! EYE!"

- Ozzy Osbourne


Had to read this to my hubby...we had a good laugh!
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Quoting Grothar:


Can I have a link to that ad?

All I get on here are ads for cemeteries and arthritis creams.
Really? I get ads for puppies and rainbows.
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If Isaac decides to not visit NOLA I believe Cantore may have a coranary. He is salivating for some action.
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Quoting Masquer08er:
Cool but no rain right now on Old Shell at mcGregor


No rain between Dauphin and Airport.
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1104. drj27
Quoting HCW:


Sorry you cheer for the wrong team :) Now back to Isaac
Lmao WDE 5 days
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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.

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