Ida takes aim at the U.S. Gulf Coast

By: Dr. Jeff Masters , 11:17 PM GMT on November 08, 2009

Share this Blog
1
+

Hurricane Ida burst into the Gulf of Mexico as a Category 2 hurricane with 100 mph winds this afternoon, and is poised to deliver a solid blow to the U.S. Gulf Coast between Southeast Louisiana and the Florida Panhandle on Tuesday morning. Radar imagery out of Cancun reveals that Ida has retained its tight inner core this afternoon, with only limited rain bands affecting Mexico and western Cuba. Top winds at Cancun, Mexico today were only 15 mph, despite the fact that Ida passed just 60 miles east of the city. Infrared and visible satellite loops show little change in the intensity of Ida's heavy thunderstorms this afternoon, but the cloud pattern is beginning to become distorted due to strong upper-level winds from the southwest that are creating 20 - 25 knots of wind shear over the hurricane. Water vapor satellite imagery reveals a large area of dry air to the southwest of Ida, but this dry air has not yet intruded into Ida's core. The latest 5:30 pm EST vortex report from the Hurricane Hunters showed that the central pressure had risen 1 mb, to 977 mb, but that the surface winds were still near 100 mph. They noted that the eyewall was open to the east, a sign that Ida's inner core may be in trouble.


Figure 1. MODIS satellite image from NASA's Terra spacecraft, taken at 1:35 pm EST 11/08/09. Image credit: NASA.

The intensity forecast for Ida
The high wind shear of 20 - 25 knots currently affecting Ida is forecast to persist at that level until Monday night. With the storm now beginning to show a distortion of the cloud pattern due to this shear, it would not be a surprise of the shear managed to inject some dry air into Ida's core Monday morning, significantly weakening the storm. Aiding this process will be cooler waters. Early Monday morning, Ida will be crossing over waters of 26°C, which is barely enough to support a hurricane. By Monday night, wind shear is expected to increase to 40 knots, which ordinarily would begin to tear the storm apart. This wind shear is due to an extratropical low pressure system over the western Gulf of Mexico, and this low will begin dumping cold, stable air into Ida Monday night through Tuesday. This will cause Ida to begin transitioning to an extratropical storm, and it is possible that during the transition Ida's winds will die down relatively slowly, despite the wind shear. The intensity forecast has a high amount of uncertainty, and I wouldn't be surprised at a landfall strength anywhere in the range of 45 mph - 80 mph. My personal best guess is a 50 - 60 mph tropical storm at landfall. Regardless of Ida's strength at landfall, the storm will be able to dump 4 - 8 inches of rain along the Gulf Coast, from New Orleans to Panama City. Isolated tornadoes will also be possible, primarily to the right side of Ida's track.


Figure 2. Maximum storm surge (depth of water above ground) for a Category 1 hurricane with 85 mph winds moving north-northeast at 15 mph. Ida is expected to be moving at this speed and direction at landfall, but will probably be weaker, so surges will not be this high. Image credit: NOAA SLOSH model run for Mobile Bay, 2008 version. Heights are given relative to the NAVD88 datum.

The storm surge forecast for Ida
Storm surge is the other major concern for Ida. With a strong high pressure system anchored over the U.S. today, the pressure difference between this high and Ida is creating a strong pressure gradient that will drive tides 3 - 5 feet above normal from New Orleans to the Florida Panhandle tonight. As Ida approaches on Monday, an additional rise in water will occur, and a large stretch of coast will be subject to very high water levels for an extended period of time. With battering waves building Monday afternoon into Tuesday morning, a significant coastal erosion event is shaping up. A particular concern is the western end of Alabama's Dauphin Island, where storm surges from four hurricanes over the past fifteen years have caused heavy damage to the low-lying heavily developed island. If Ida makes a direct hit on Mobile Bay as a Category 1 hurricane with 85 mph winds, a storm surge of up to six feet is possible there, assuming the storm hits at mean tide. The tidal range along the Gulf Coast varies by about 1.5 feet between low and high tide (Figure 3). High tide is near 2 am EST on Tuesday, but the official NHC forecast currently has the storm hitting between 6 am - 9 am, when the tide will be going out, so the storm may indeed be hitting at about mean tide.


Figure 3. The tide forecast for the Gulf Coast calls for high tide to occur around 2 am EST Tuesday morning. Ida is expected to hit later that morning, while the tide is going out.

I'll have an update Monday morning.

Links to follow:

U.S. Severe Weather Page
Cancun radar

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: 741 - 691

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 | 38Blog Index

Going to watch CNN at 9 to see if they actually care enough to devote a large chunk of time to IDA.
Member Since: Posts: Comments:
what is the chance of a miss. landfall?..Im seeing alot of people saying that landfall will be east of miss.
Member Since: Posts: Comments:
NEXRAD Radar
New Orleans, Storm Relative Mean Radial Velocity 1.45 Degree Elevation Range 124 NMI


Member Since: July 3, 2005 Posts: 424 Comments: 128344
Quoting Patrap:


U betcha sweet bippy Ike.

Im concerned for SE Miss and over to you as well padna.


Im concerned of SE Miss as well because I live there haha.
Member Since: Posts: Comments:
Quoting Patrap:
Lotsa stuff going on "east" of Fla Now o Reed Jedi..LOL



Still got that virga mess goin on... no rain yet. LOL
Member Since: Posts: Comments:
Quoting KATRINABILOXIGIRL:
I was talking about your car...
ohh working tomorrow so will probably move it when I come back. I have to go to LA for a while then I will park in the garage
715. SouthALWX 2:41 AM GMT on November 09, 2009
Quoting stormsurge39:
Im talking about Monday from 7am until 3pm! Sheesh Think about it

another point, kids will be on the roads well after 3pm .. all kids are off the bus by what 4:30-5 ish?


at the rate it's going...and seems to be picking up speed as we write...could very well feel the winds as early as noon on Monday..so yes it's a very good idea to go ahead and close them and not risk putting them on the roads much less having alot of parents getting there kids....but hey that's just me didn't mean to insult anyone...so my bad if i did....
Member Since: Posts: Comments:
Just about due west of Key West. I foresee hurricane watches moved up to warning at 10 pm she is starting to move quick now.
Member Since: Posts: Comments:
Quoting alaina1085:
Whoever mentioned the virga word to me, I now know what it is! LOl.. learn something new everyday.


LOL

nice!
Member Since: Posts: Comments:
Lotsa stuff going on "east" of Fla Now o Reed Jedi..LOL

Member Since: July 3, 2005 Posts: 424 Comments: 128344
Quoting P451:


I viewed the image directly full size, then used photoshop to crop it - then rehosted the image.


thx
Member Since: Posts: Comments:
Quoting IKE:


Tropical storm conditions likely.




Trees....house up on blocks...shakes with 50+ mph winds...
Where about in DFS do you live Ike, Barry.
Member Since: Posts: Comments:
wow...look at the wind speeds just south of LA from those dropsondes...over 30kts at the surface. No where near Ida. Must all be from the BOC low.
Member Since: Posts: Comments:
I'm hoping she never sees 88W.
Quoting IKE:


Hopefully it will turn...and weaken...a lot.

ECMWF had it coming into SE LA.

Just hope it weakens.


U betcha sweet bippy Ike.

Im concerned for SE Miss and over to you as well padna.
Member Since: July 3, 2005 Posts: 424 Comments: 128344
Whoever mentioned the virga word to me, I now know what it is! LOl.. learn something new everyday.
Member Since: Posts: Comments:
Quoting Nolehead:
654. ALCoastGambler 2:29 AM GMT on November 09, 2009
Well now that I see Mobile Bay is on the West side I am off to the poker table.ya'll play nice and pray that the waves do not wash my car away. I am parked under the casino


what gave you the idea that mobile bay is out of the clear?? um it's still on the same path
Now I never said that. I said on the West side. Never said in the all clear
Quoting IKE:


On the course it's on it looks headed right for the mouth of the Mississippi.
yep iam trackin it to someones front door who remains to be seen
Member Since: Posts: Comments:
Quoting ALCoastGambler:
Ohh I'm on the 6th floor...lol My car is ummmmmmm not...lol
I was talking about your car...
Member Since: Posts: Comments:
I think landfall will be either the central Panhandle or eastern Panhandle of Florida, wouldn't be surprised if the trough strengthens more and steers Ida into the northern Peninsula. Go ahead, bash me, hurt me, call me a eastcaster, I just don't see this hitting west of Florida..
Member Since: July 1, 2008 Posts: 13 Comments: 7390
NNW steady as she goes
Member Since: Posts: Comments:
Quoting stormsurge39:
Im talking about Monday from 7am until 3pm! Sheesh Think about it

another point, kids will be on the roads well after 3pm .. all kids are off the bus by what 4:30-5 ish?
Member Since: Posts: Comments:
I live less than an mile from Ike more than likely. I am on Kings Lake. We wont be leaving though even if eye comes right over.
Member Since: Posts: Comments:
Member Since: July 3, 2005 Posts: 424 Comments: 128344
712. IKE
Quoting theFatherofNature:
I live in Chickasaw Alabama, a suburb just to the north of mobile and I was wondering if it was possible that We could see hurricane force winds here in Chickasaw?


I would say yes.
Member Since: Posts: Comments:
704. What software did you use to zoom like that without loosing detail.
Member Since: Posts: Comments:
wow more closures in hancock county now...really? they are so far west compared to others. Even a college canceled classes after 1pm.
Member Since: Posts: Comments:
Quoting Nolehead:
675. rinkrat61 2:34 AM GMT on November 09, 2009
Quoting stormsurge39:
Mobile county is hardcore! Ive got kids in school here and i dont see any reason to close Monday anywhere on the Gulf Coast.

WOW!!!!!!yer kidding,,right



yeah hardcore that's why 1/2 of Mobile floods during a regular rain storm.....you go with your hardcore self....at least i know my kids will be safe...
Im talking about Monday from 7am until 3pm! Sheesh Think about it
Member Since: Posts: Comments:
Currently still on a NNW heading for Ida
Member Since: Posts: Comments:
Quoting KATRINABILOXIGIRL:
Yikes...ur scaring me now...


Hes talking about if the storm continued NNW, which it won't
Member Since: Posts: Comments:
Quoting Patrap:
My Open Tracker shows Nw at 340 at 14mph


I Hope thats wrong Ike.


Floater AVN Color Imagery Loop
340?! Thats no good. Especially at that speed
Quoting stormsurge39:
70mph winds are not going to be here during school Monday! Whats up with the crazy insult? I love my kids and would not send them in harms way!! Do you really think 70mph winds will be here from 7am until 3pm on Monday?LMAO

I think it's possible. And I really think it's possible that 50+ mph gusts will be. Have you not seen the gradient setting up?
Member Since: Posts: Comments:
703. IKE
Quoting Patrap:
My Open Tracker shows Nw at 340 at 14mph


I Hope thats wrong Ike.


Floater AVN Color Imagery Loop


Hopefully it will turn...and weaken...a lot.

ECMWF had it coming into SE LA.

Just hope it weakens.
Member Since: Posts: Comments:
wow, she's in the gulf.
Member Since: Posts: Comments:
Hurricane Preparation Entry
Member Since: July 3, 2005 Posts: 424 Comments: 128344
Quoting KATRINABILOXIGIRL:
I would defintiely move up a couple of floors before you take that seat at the poker table...
Ohh I'm on the 6th floor...lol My car is ummmmmmm not...lol
654. ALCoastGambler 2:29 AM GMT on November 09, 2009
Well now that I see Mobile Bay is on the West side I am off to the poker table.ya'll play nice and pray that the waves do not wash my car away. I am parked under the casino


what gave you the idea that mobile bay is out of the clear?? um it's still on the same path
Member Since: Posts: Comments:
Quoting IKE:


On the course it's on it looks headed right for the mouth of the Mississippi.
Yikes...ur scaring me now...
Member Since: Posts: Comments:
Quoting stormsurge39:
Mobile county is hardcore! Ive got kids in school here and i dont see any reason to close Monday anywhere on the Gulf Coast.


Schools here are used as shelters. With coastlines being evacuated starting in the morning they need the schools. Because the district encompasses the whole county, they close them all because it creates a logistical nightmare otherwise.
Member Since: August 22, 2008 Posts: 12 Comments: 6010
I live in Chickasaw Alabama, a suburb just to the north of mobile and I was wondering if it was possible that We could see hurricane force winds here in Chickasaw?
Member Since: Posts: Comments:
695. xcool
lol matt
Member Since: September 26, 2009 Posts: 2 Comments: 15672
My Open Tracker shows Nw at 340 at 14mph


I Hope thats wrong Ike.


Floater AVN Color Imagery Loop
Member Since: July 3, 2005 Posts: 424 Comments: 128344
692. BDAwx
hmmm... us bermudians must have been doing it wrong all this time.... we let our students go to school and in the middle of the day get an email saying winds nearing or exceeding hurricane force have created unsafe driving conditions across the causeway. which means that Bermuda pretty much shuts down, packs, up, and goes home... then they close the causeway.
Member Since: Posts: Comments:
Quoting SouthALWX:

driving in 70+mph winds is crazy and so are you for thinking it's not =P
70mph winds are not going to be here during school Monday! Whats up with the crazy insult? I love my kids and would not send them in harms way!! Do you really think 70mph winds will be here from 7am until 3pm on Monday?LMAO
Member Since: Posts: Comments:

Viewing: 741 - 691

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 | 38Blog 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
71 °F
Overcast