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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903. auburn (Mod)
Quoting Tazmanian:



keep the politics crap off this blog


you tell it Taz! :)
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Quoting trinigal:


Weather, please! I've just been wondering about all the Obama ads here. That is all I ever seem to see and saw an opportunity to ask. I don't really care about the political affiliations of each member here. I'm pretty much a lurker and just want to understand this storm :)

Okay, read StormHype's answer and really did laugh out loud.
Politics is always fun, unless it's interfering with my wx talks... lol like enjoying both sugar and pepper, but not necessarily at the same time... lol

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Quoting Caner:
I'm in a bit of a fix...

Went out to get my cable that i hook the generator to the house wiring with only to discover it missing...

Haven't used it since Gustav >.<

I had the kitchen re-floored like a year and a half ago, only thing i can figure is one of the workers lifted it for scrap copper then...

Went to Lowes and The Home Depot, both were out of the 30 amp twist lock plug i need... Guess im gonna have to take off work in the morning and hit up the electrical supply houses, hopefully they aren't out or i am screwed.


If they are out, try a marine store. Similar plugs (I think).
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With the rate Isaac is going I don't think he'll ever be a hurricane.
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I think Isaac has just formed an eye !!!
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Not a drop hardly (sprinkles earlier) today. Would have thought by looking at the radar we would be under a deluge by now. Wow.
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Quoting moonlightcowboy:




I don't know what modeling makes up this chart, but I keep coming back to it for some reason.

I'm not a big modeling person although I totally admit their necessity as a great tool - improvement have been great, especially the past couple of years it seems. I'm an old school hobbyist with an interest in these storms since I was a boy with Camille. All of these tools are great! I watch sats, sfc maps, the other charting; but this time, this time, I've paid even less attention to the modeling and even less attention to the CIMSS steering charts. Those charts fooled me with Ernesto, so I omitted them this time.

With Isaac moving wnw/nwest this rain chart reflects, imo, Isaac's eventual route inland, as it points directly to the upper west end point of the 1016mb which ends at the tail of the shortwave trough that has deepened and now extends into TX towards Ohio. IMO, currently, this direction points to the weakest escape route for Isaac inland.

Now, I'm starting to get concerned about his forward speed and the plains high closing in. Starting to think an inland stall is quite likely.


From the looks of that,if he stalls, then it is gonna get ugly quick. Hope the Coast Guard has the Airsupport ready. Also hope that FEMA has the USAR Swift Water Rescue Teams on alert.


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Quoting shred3590:


Here is the reason for the LOL. The storm has been moving NW since the Keys. Current recon says NW movement. All of the models show NW movement to landfall. The NHC is forecasting continued NW movement. The steering layers call for NW movement until landfall, but some disagreement as to speed of advancement. In short, all knowledgeable sources say NW movement. You come in and say due north with absolutely no justification for your statement.

If you explain your comment with support from the available data, then you will get disagreement, but actual discussion. Off the wall statements with no support get LOLs.


I was looking at radar, center looks to be moving due north on it, I actually think steering does not favor a continuous move to the NW.



oh right I forgot, there is no weakness there at all. I say landfall is in either AL or MS, but not LA. If I am wrong, I am wrong
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Quoting Caner:
I'm in a bit of a fix...

Went out to get my cable that i hook the generator to the house wiring with only to discover it missing...

Haven't used it since Gustav >.<

I had the kitchen re-floored like a year and a half ago, only thing i can figure is one of the workers lifted it for scrap copper then...

Went to Lowes and The Home Depot, both were out of the 30 amp twist lock plug i need... Guess im gonna have to take off work in the morning and hit up the electrical supply houses, hopefully they aren't out or i am screwed.


its only electicity.. :)
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Quoting Hypemachine:



Just wait Obama will be in NO claiming victory after the overhyped Issac causes minimal damage.


Welcome new and informed member...and the storm's name is spelled Isaac. We look forward towards your contributions!
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Going to try and drive to Waveland, MS from Pensacola before conditions are too nasty to drive in...hoping to get some good footage of the eyewall.
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Quoting seafarer459:

Tell me about it. I lived there for 12 years.


City Council just permanently banned alcohol on the beach...it'll never be the same...my place is at E Ashley and 4th
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Quoting greene47:


I thought this was at the base commander's discretion?..We were not ordered to evac for the "K" storm, so I really don't see Hurbie or Eglin getting the order for Issac


The son is spinning it to fuzz up his momma...there is no directive from POTUS... Still base commanders directive.
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Quoting Grothar:


I was talking to myself about the same thing, half of me says Yes, and the other half says No. Of course I think I'm right.
We think you are both right.
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Quoting leelee75k:


looks like the blob that was Isaac's east side broke off and is now off the east coast of Florida. I notice that the clouds in South Florida are no longer racing to the Northwest. Not sure if he will be able to wrap any of that up into his circulation.


I believe it's now a surface trough with no relationship to Isaac. That being said, there's a lot of dry air surrounding the "blob" and it may not hold together very well until it moves towards Alabama. What little has made it around the horn is drying up as it leaves Georgia. There's not even much rain directly on the coast.
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Quoting trinigal:


Weather, please! I've just been wondering about all the Obama ads here. That is all I ever seem to see and saw an opportunity to ask. I don't really care about the political affiliations of each member here. I'm pretty much a lurker and just want to understand this storm :)

Okay, read StormHype's answer and really did laugh out loud.
Ghostery is your friend...
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The dry sinking air has been brutal this season. If Isaac never gets it's core going it will never become a hurricane. Conditions will not become any better here on out. Isaac will be getting closer to land and pulling in more dry air. The GOM is more stable than usual and water temps are not as high as they could be. The W Atlantic basin isn't going to flick like a light switch and have outstanding conditions anytime soon.
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Quoting CaicosRetiredSailor:
Bahamian politics?
Trini politics?
or TCI politics?

: )
Any one of the three could be a hot topic in a SECOND.... lol

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Quoting CaicosRetiredSailor:
Bahamian politics?
Trini politics?
or TCI politics?

: )



keep the politics crap off this blog
Member Since: May 21, 2006 Posts: 5091 Comments: 115455
Tightening up.......look like a tiny eye clearing though it could just be the dry air to the north causing that

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Quoting leelee75k:


looks like the blob that was Isaac's east side broke off and is now off the east coast of Florida. I notice that the clouds in South Florida are no longer racing to the Northwest. Not sure if he will be able to wrap any of that up into his circulation.
Yes, the blob has become its own entity. Don't think Isaac can pull that back in.
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Quoting presslord:
Can somebody please give me the nutshell, third grade version of what's happening with Isaac?


Took in some dry air and disrupted what eye wall he'd been building.
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Quoting AllyBama:
Good evening to all of the Mobilians on here tonight! Guess we are still watching and waiting..


Hey Ally. Yes , waiting, and waiting, and then some more waiting.
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877. FOREX
Quoting FL1980:
I'm sure I will get bashed for this but The Weather Channel is horrible. More of a hype Machine if you ask me. Doesn't help them that they are owned by NBC.


I knew NBC would ruin them. My Grandfather told me that when he was a kid, Al Roker would have been no more than one of those guys who make animals out of balloons for kids at your nearest restaurant.
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Quoting BahaHurican:
I find it hard to think the President would suddenly interefere in military procedure like that. I mean, don't they have generals and stuff? Additionally, Pr. Obama hasn't seemed like someone who would put people in harm's way without some valid reason.

Like I said in an earlier post, something sounds fishy about that order.

Whatever the real deal is, aislinn, I hope your boy is going to be OK... gotta be a tense time for a mom.


He is the commander in Chief and can make these decisions. I just wonder if he looked at the maps...
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Quoting trinigal:


Weather, please! I've just been wondering about all the Obama ads here. That is all I ever seem to see and saw an opportunity to ask. I don't really care about the political affiliations of each member here. I'm pretty much a lurker and just want to understand this storm :)
Not sure I'd want them to say, "This storm brought to you by Masquer08er."
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Quoting presslord:



Oh, man!!! Truer words were never spoken....

Tell me about it. I lived there for 12 years.
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AL, 09, 2012082800, 267N, 865W, 60, 981, TS
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Quoting syn627:

LOL...glad I'm not the only one noticing that. It's very confusing...like the blog has a "split personality" or somethin like dat.


I was talking to myself about the same thing, half of me says Yes, and the other half says No. Of course I think I'm right.
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I wasn't sure that any storm would pass Ernesto in craziness this year, but it seems as though Isaac has done just that. haha
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Quoting Masquer08er:
About to run to CVS the home for the duration. Decided to refill early...in case. Something for folks to think about in case it's a couple of days before they can get meds.


Good idea. I did it at Walgreens earlier!
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Good evening to all of the Mobilians on here tonight! Guess we are still watching and waiting..
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Quoting Hurricanes101:


you laugh but do not give me a reason as to why

Typical troll


Here is the reason for the LOL. The storm has been moving NW since the Keys. Current recon says NW movement. All of the models show NW movement to landfall. The NHC is forecasting continued NW movement. The steering layers call for NW movement until landfall, but some disagreement as to speed of advancement. In short, all knowledgeable sources say NW movement. You come in and say due north with absolutely no justification for your statement.

If you explain your comment with support from the available data, then you will get disagreement, but actual discussion. Off the wall statements with no support get LOLs.
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7mb drop from 11am EDT to 5pm EDT ?
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Quoting greene47:


I thought this was at the base commander's discretion?..We were not ordered to evac for the "K" storm, so I really don't see Hurbie or Eglin getting the order for Issac


As I said, this just came down this morning.
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I'm sure I will get bashed for this but The Weather Channel is horrible. More of a hype Machine if you ask me. Doesn't help them that they are owned by NBC.
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Quoting WetBankGuy:



WetBank ,this explains a lot. I cannot say that I blame you.
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Quoting seafarer459:

So, If I'm 149 miles away, I have to drive to a military shelter? What a crock. Does this guy just pull stuff out of his ??? As far as I know, this has never been policy.
I find it hard to think the President would suddenly interefere in military procedure like that. I mean, don't they have generals and stuff? Additionally, Pr. Obama hasn't seemed like someone who would put people in harm's way without some valid reason.

Like I said in an earlier post, something sounds fishy about that order.

Whatever the real deal is, aislinn, I hope your boy is going to be OK... gotta be a tense time for a mom.
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Quoting keithneese:


Channel 5 here in Mobile said a little while ago that high tide was at 10 tomorrow morning.


Good site for Gulf Coast tides:
http://tbone.biol.sc.edu/tide/sites_usgulf.html
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Quoting TampaFLUSA:
There is hardly any precipitation east of the center.


looks like the blob that was Isaac's east side broke off and is now off the east coast of Florida. I notice that the clouds in South Florida are no longer racing to the Northwest. Not sure if he will be able to wrap any of that up into his circulation.
Member Since: September 9, 2005 Posts: 0 Comments: 562
Quoting seafarer459:

Folly Beach has never been in the clear. A constant fog has always enveloped that tiny sand spit.



Oh, man!!! Truer words were never spoken....
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Quoting presslord:
Can somebody please give me the nutshell, third grade version of what's happening with Isaac?


Landfall over NOLA or just east as a strong TS or Cat1. Slowing and plenty of rain east of the storm (MS/AL).

Get a boat.. or floaties..
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Quoting mobilebayal:



Me too! The clouds do look weird.
About to run to CVS the home for the duration. Decided to refill early...in case. Something for folks to think about in case it's a couple of days before they can get meds.
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Quoting BahaHurican:
The Republicans could prolly buy just as many ads if they wanted to. More, actually, since the news people keep talking about how much money the Republicans have.

So are we going to talk politics now, or weather?


{big grin}


Weather, please! I've just been wondering about all the Obama ads here. That is all I ever seem to see and saw an opportunity to ask. I don't really care about the political affiliations of each member here. I'm pretty much a lurker and just want to understand this storm :)

Okay, read StormHype's answer and really did laugh out loud.
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Quoting TomballTXPride:

yeah. Folly beach is in the clear. how's that.

Folly Beach has never been in the clear. A constant fog has always enveloped that tiny sand spit.
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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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