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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1804. snotly
if you really want to talk nostalgia we need to discuss TUBES!
Member Since: Posts: Comments:
Quoting LAlurker:

Barge didn't impact the levee, it got sucked into the hole in the failed levee.


Nope, sorry. Barge crashed through the levee wall.....talked to people who were there. But the water came from the Chalmette anyway....25 feet of it.
Member Since: June 16, 2006 Posts: 0 Comments: 1565
Quoting cjnew:


I think turtle was a younger fellow so He may be in college or somtheing..... I may be way off base though.


wasn't he like 16, had his own website and was already interning at the NHC or something like that? I need to google..
Member Since: August 3, 2006 Posts: 132 Comments: 20635
1801. tkeith
Quoting Beachfoxx:
Sitting here on the Western Panhandle you would never know Isaac was out there. No wind, no rain - so far. We secured everything yesterday & there are about 30 boats out in the bayou seeking safe harbor...
It is eerily quite...
plenty of wind here Beach... no rain yet.

But it's early :)
Member Since: Posts: Comments:
1800. Scotth
In case anyone is wondering what happened to Lefty, he is in Ohio. But do you remember when he went to OBX with killdevilhillsmax? Stormjunkie has a pic of him that day!
Member Since: August 4, 2004 Posts: 0 Comments: 23
Hurricane Bill of 2009 had a pressure of 980 mb while having winds of 70 mph.
70 mph 110 kph 980 mb Tropical Storm
In contrast, Hurricane Lorenzo of 2007 had a pressure of 1001 mb while having winds of 70 mph.
70 mph 110 kph 1001 mb Tropical Storm
Member Since: September 7, 2006 Posts: 89 Comments: 2655
More old timer trivia:

Who was the poster who would say "Hey Killer" every time Adrian would post something?

Not sure why I remember this but I do. HA.

Member Since: Posts: Comments:
Try? We were begging people to evacuate!
Quoting taco2me61:
Don't get me wrong but "We Did Try" thats for sure but they would not listen.... and a lot of people lost the Lives during that storm....

Taco :o)
Member Since: July 10, 2005 Posts: 157 Comments: 29384
Quoting RTSplayer:
Linear extrapolation says the storm will pass 29 miles due west of NOLA, putting them directly under the right front quadrant of whatever eye wall development there may be.

A few hours later, I should be in the same case. I intend to document it all with my digital camera.



Oh, by the way, there is an enormous lunar halo out tonight. It's the largest I've ever seen.


Yeah I just looked at it ..Beautiful...
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Quoting nola70119:


Can't really see how Mississippi gets that, but what do I know?


You have been doom casting the last 46 hours. Must be disapointed
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1794. vanwx
Quoting cjnew:
Foxx the dry air has really made it not bad here. we barely got any rain. waiting to see if that stays through tomorrow.

Does anyone remember when Dr. Masters blog was lucky to break 50 comments? ha. who knew.
now he's on TWC.


1992
Member Since: Posts: Comments:
Sitting here on the Western Panhandle you would never know Isaac was out there. No wind, no rain - so far. We secured everything yesterday & there are about 30 boats out in the bayou seeking safe harbor...
It is eerily quite...
Member Since: July 10, 2005 Posts: 157 Comments: 29384
1792. JeffM
Here is something for all of us that were here posting during Katrina 7 YEARS ago!! It's the blog from Katrina.

Link
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Quoting HCW:


He is getting his feet rubbed and riding around in Storm W's mustang j/k. He is on vacation and will be back next week



Did that just happen?....lol
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1790. will40
Quoting AllyBama:


yes he was here for a post of two



remember that time i think it was his g/f that got on his pc and caused a riot ?
Member Since: September 19, 2005 Posts: 2 Comments: 4251
Quoting nola70119:


Sort of.....it was a barge that sank the Lower Ninth. New Orleans East just got surged.....Chalmette got MRGO'ed.


Barge didn't impact the levee, it got sucked into the hole in the failed levee.
Member Since: Posts: Comments:
Linear extrapolation says the storm will pass 29 miles due west of NOLA, putting them directly under the right front quadrant of whatever eye wall development there may be.

A few hours later, I should be in the same case. I intend to document it all with my digital camera.



Oh, by the way, there is an enormous lunar halo out tonight. It's the largest I've ever seen.
Member Since: January 25, 2012 Posts: 33 Comments: 1520
1787. bassis
Quoting Beachfoxx:
This is the strangest, most confusing storm!


I can't imagine what he would look like if he did not have such a massive appetite for dry air for his life as a TC
Member Since: Posts: Comments:
Quoting CallInBatonRouge:


I was here for Katrina, too. This blog was my sanity. It was a miracle to me that so many talents aligned to pre-warn so many people. Even without the ants, this blog called the devastation days before the NHC. It was actually difficult to get non-bloggers to listen but the certainty and evidence presented here made it possible to convince them. Forever grateful.

Yeah, I'm sure this blog convinced some folks to evac from nola that wouldn't have otherwise - or at least convinced them to go sooner. Lefty and Stormw were all over it calling for evac's while waiting for Nagin to.
Member Since: August 28, 2005 Posts: 0 Comments: 153
1785. GBguy88
Quoting GPTGUY:


He said he is going to spend the storm in Waveland he wants to film the highest surge..he says he has a plan if the water gets to high and will float with it


Uhhh...I'm heading to Waveland also, but I'm not dumb enough to "float with" the storm surge. No sir. I'm only interesting in getting the winds/rain on video.
Member Since: Posts: Comments:
1784. HCW
Quoting LuvsStorms:



Where is patrap???? Long time lurker and missing him.


He is getting his feet rubbed and riding around in Storm W's mustang j/k. He is on vacation and will be back next week
Member Since: Posts: Comments:
1783. cjnew
Quoting AllyBama:
Does anyone know what happened to TurtleHurricane?


I think turtle was a younger fellow so He may be in college or somtheing..... I may be way off base though.
Member Since: Posts: Comments:
Quoting CallInBatonRouge:


I was here for Katrina, too. This blog was my sanity. It was a miracle to me that so many talents aligned to pre-warn so many people. Even without the ants, this blog called the devastation days before the NHC. It was actually difficult to get non-bloggers to listen but the certainty and evidence presented here made it possible to convince them. Forever grateful.
Don't get me wrong but "We Did Try" thats for sure but they would not listen.... and a lot of people lost the Lives during that storm....

Taco :o)
Member Since: Posts: Comments:
Can someone really quickly tell me what is going on, I'm on Xbox
Member Since: June 17, 2011 Posts: 11 Comments: 6539
1780. tkeith
Quoting Orcasystems:
Cue the shower curtains... jesting.. please don't.
canadians...jeesh :)
Member Since: Posts: Comments:
Quoting cjnew:


I'm pretty sure I saw Adrian a few days ago... he just posts 1 or 2 things.
It could have been someone else though... since there are quite a few hurricane inspired handles.


yes he was here for a post of two
Member Since: August 3, 2006 Posts: 132 Comments: 20635
Quoting CaicosRetiredSailor:



vary close to a

pin

hole

: )

is there a term for wishcasting the pinhole?
"Pincasting"?
Member Since: Posts: Comments:
1777. tkeith
Quoting LAlurker:

MRGO has been permanently closed and there is a flood gate in the ICWW to keep Lake Borgne out of the Industrial canal (Inner Harbor Navigation Canal). There is also a new gate in the Industrial canal near Lake Pontchartrain but not sure if it is complete yet.
yes it's complete...Seabrook
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Quoting moonlightcowboy:


Thanks, Kman, so what about landfall, coordinates and intensity. We're hanging on here! We've got all this Spam and all this Cold Beer, but we're not sure we bought enough! Do tell, friend. ;)


Open a cold one and make a sandwich !.

NW to just South of landfall is still my position. I like the NHC track with a slight adjustment to the right. The plains high has pushed East and strengthened a bit which will increase the block to the NW. We may see more of a NNW motion near landfall IMO.

As for intensity Cat 1 looks more and more likely absent a significant deepening near the coast. The TCHP levels do not favour that and the inability of Isaac to get it together this afternoon suggests that it is running out of time to do much on the intensity front.
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1775. snotly
structure reforming, ... or at least trying to.
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Highest reading yet...

Peak (10s) Flt. Lvl. Wind: 70 knots (~ 80.5 mph)
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1773. cjnew
Quoting hahaguy:

You're right. Adrian was on a few days ago but onyl posted a few things.

AH! See it is verified. I know things.

thanks guy!
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Quoting caneloader:


If I'm correct (tired) they've got gates now to shut off the Industrial Canal - the lack thereof during Katrina which was what sank New Orleans East.

MRGO has been permanently closed and there is a flood gate in the ICWW to keep Lake Borgne out of the Industrial canal (Inner Harbor Navigation Canal). There is also a new gate in the Industrial canal near Lake Pontchartrain but not sure if it is complete yet.
Member Since: Posts: Comments:
Brian Ozborne Cyclone OZ
Quoting mtyspider:
Do anybody remember a crazy guy waiting for a landfall in a jeep and a camera pointing to a umbrella or gas station canopy. Somebody remember the name??? am pretty intrigued ,maybe he would pull that stunt again. Not pretty smart or hurricane savie ..but really funny to listen to.
Member Since: Posts: Comments:
1770. Scotth
I'm an oldie! Hey all! Good to see you all again.

Member Since: August 4, 2004 Posts: 0 Comments: 23
Quoting Caner:
most recent microwave:



Can't really see how Mississippi gets that, but what do I know?
Member Since: June 16, 2006 Posts: 0 Comments: 1565
Quoting IMA:


Taz has been eating your shoes??


Ha! Avoiding that possibility is why I've lurked, really. :D
Member Since: Posts: Comments:
1767. will40
remember we use to say StormTop used a cropduster for recon lol?
Member Since: September 19, 2005 Posts: 2 Comments: 4251
1766. GPTGUY
Quoting Orcasystems:


That man is swimming in a very very shallow gene pool.


He said he is going to spend the storm in Waveland he wants to film the highest surge..he says he has a plan if the water gets to high and will float with it
Member Since: Posts: Comments:
1765. hahaguy
Quoting cjnew:


I'm pretty sure I saw Adrian a few days ago... he just posts 1 or 2 things.
It could have been someone else though... since there are quite a few hurricane inspired handles.

You're right. Adrian was on a few days ago but only posted a few things.
Member Since: Posts: Comments:
and who could ever forget JFV...LMAO!! fun times..
Member Since: Posts: Comments:



vary close to a

pin

hole

: )
Member Since: July 12, 2007 Posts: 0 Comments: 6049
Quoting BlxMS:


Think I joined that night too....I'm 57 and have to admit....seven years ago right now, I was as afraid as I had ever been...and experienced nothing like it since..


I was here for Katrina, too. This blog was my sanity. It was a miracle to me that so many talents aligned to pre-warn so many people. Even without the ants, this blog called the devastation days before the NHC. It was actually difficult to get non-bloggers to listen but the certainty and evidence presented here made it possible to convince them. Forever grateful.
Member Since: Posts: Comments:
Quoting atmosweather:


Wasn't it Cyclone Oz?


Yessss , That's the one!!!!!!thank u so much,
Member Since: Posts: Comments:
Quoting Jwd41190:


Wikipedia is wrong and is never a reliable source look at image below


Actually, Wikipedia is right.
Leslie reached 70 mph while extratropical.
Storm LESLIE is number 12 of the year 2000
************************************************
Month Day Hour Lat. Long. Dir. ----Speed----- -----Wind------ Pressure ------------Type-----------
October 4 12 UTC 29.0N 81.4W -- deg -- mph -- kph 35 mph 55 kph 1012 mb Subtropical Storm
October 4 18 UTC 29.5N 80.8W 45 deg 8 mph 12 kph 35 mph 55 kph 1012 mb Subtropical Storm
October 5 0 UTC 29.7N 79.9W 75 deg 9 mph 14 kph 35 mph 55 kph 1010 mb Subtropical Storm
October 5 6 UTC 29.8N 78.6W 85 deg 12 mph 20 kph 35 mph 55 kph 1010 mb Subtropical Storm
October 5 12 UTC 29.9N 77.3W 85 deg 12 mph 20 kph 40 mph 65 kph 1009 mb Tropical Storm
October 5 18 UTC 30.2N 75.9W 75 deg 13 mph 22 kph 40 mph 65 kph 1009 mb Tropical Storm
October 6 0 UTC 30.3N 74.3W 85 deg 14 mph 24 kph 40 mph 65 kph 1010 mb Tropical Storm
October 6 6 UTC 30.6N 73.1W 75 deg 11 mph 18 kph 45 mph 75 kph 1006 mb Tropical Storm
October 6 12 UTC 30.9N 72.4W 65 deg 6 mph 11 kph 45 mph 75 kph 1007 mb Tropical Storm
October 6 18 UTC 31.3N 71.8W 50 deg 6 mph 11 kph 45 mph 75 kph 1007 mb Tropical Storm
October 7 0 UTC 32.1N 70.7W 50 deg 13 mph 22 kph 45 mph 75 kph 1006 mb Tropical Storm
October 7 6 UTC 33.1N 69.6W 45 deg 14 mph 24 kph 45 mph 75 kph 1006 mb Tropical Storm
October 7 12 UTC 35.4N 68.3W 25 deg 28 mph 46 kph 45 mph 75 kph 1006 mb Tropical Storm
October 7 18 UTC 37.4N 66.7W 35 deg 26 mph 42 kph 45 mph 75 kph 1005 mb Extratropical Storm
October 8 0 UTC 40.0N 64.0W 40 deg 37 mph 61 kph 45 mph 75 kph 1004 mb Extratropical Storm
October 8 6 UTC 43.0N 60.0W 45 deg 48 mph 77 kph 45 mph 75 kph 1003 mb Extratropical Storm
October 8 12 UTC 46.0N 57.0W 35 deg 41 mph 66 kph 45 mph 75 kph 1003 mb Extratropical Storm
October 8 18 UTC 49.0N 54.0W 35 deg 41 mph 66 kph 40 mph 65 kph 1005 mb Extratropical Storm
October 9 0 UTC 51.0N 50.0W 50 deg 36 mph 59 kph 40 mph 65 kph 1007 mb Extratropical Storm
October 9 6 UTC 53.0N 46.0W 50 deg 35 mph 57 kph 40 mph 65 kph 1006 mb Extratropical Storm
October 9 12 UTC 55.0N 41.0W 55 deg 40 mph 64 kph 40 mph 65 kph 1005 mb Extratropical Storm
October 9 18 UTC 56.0N 36.0W 70 deg 34 mph 55 kph 40 mph 65 kph 1003 mb Extratropical Storm
October 10 0 UTC 56.0N 30.0W 90 deg 37 mph 61 kph 45 mph 75 kph 999 mb Extratropical Storm
October 10 6 UTC 55.0N 24.0W 105 deg 40 mph 64 kph 60 mph 95 kph 987 mb Extratropical Storm
October 10 12 UTC 54.0N 17.0W 105 deg 47 mph 75 kph 65 mph 100 kph 980 mb Extratropical Storm
October 10 18 UTC 53.0N 10.0W 105 deg 48 mph 77 kph 70 mph 110 kph 973 mb Extratropical Storm
Member Since: September 7, 2006 Posts: 89 Comments: 2655
1759. cjnew
Quoting Beachfoxx:
Hmmm, haven't seen Adrian...
Pat is on vacation or was. I don't think he is home yet.



I'm pretty sure I saw Adrian a few days ago... he just posts 1 or 2 things.
It could have been someone else though... since there are quite a few hurricane inspired handles.
Member Since: Posts: Comments:
Quoting IMA:
Awwww, so good to see so many old, uhm, I mean "familiar" faces :) Where's JFV, though? heehee I couldn't resist!

Becareful now you will talk him up LOL :o)

Taco :o)
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Quoting GPTGUY:
They just did a story and interviewed cyclone oz on the local tv station here in biloxi


cool!
Member Since: August 3, 2006 Posts: 132 Comments: 20635
Quoting GPTGUY:
They just did a story and interviewed cyclone oz on the local tv station here in biloxi


That man is swimming in a very very shallow gene pool.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
hey everyone, i remember everyone also..storm w taz ike floodman patrap orcasystems tampa spin etc...good to see some of ther same ones on here
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1754. will40
Quoting moonlightcowboy:



Atmos, my answer would be this to the dilemma, and a question. First the question. When a dropsonde is dropped into the eye is pressure measured at the sfc or the mid-levels, or all along the way? If it's at the sfc, then Isaac's llc has been really intense today, more so than at any other time I've noticed according to vorticity charts and observations.

The MLC has been the dominant, broad circ throughout his life, and the smaller llc, trying as it may now, is having an awfully tough time trying to spin that broad mid-level circulation.

May be a bad question, but it's one I've never considered before now. TIA, friend.


i think it is measured all along the way
Member Since: September 19, 2005 Posts: 2 Comments: 4251

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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.