Ida not weakening; spreading heavy rains inland

By: Dr. Jeff Masters , 9. marraskuuta 2009 klo 20:31 (GMT)

Share this Blog
3
+

Data from the Hurricane Hunters this afternoon indicates that Ida has not weakened, and remains near hurricane strength. AT 3 pm EST, an Air Force airplane reported that the pressure had fallen to 991 mb, and a small area of hurricane force winds of 75 - 80 mph had developed in the outflow from a intense burst of thunderstorm activity on the southwest side of the eye. Surface winds elsewhere in the storm were 60 - 70 mph, so NHC decided that the hurricane-force winds seen by the Hurricane Hunters were a short-lived phenomena not worthy of upgrading Ida to hurricane strength for. In any case, heavy rains and storm surge, not wind, will be the primary threats from Ida. Heavy rains from the storm are lashing the Gulf Coast from southeast Louisiana to the Florida Panhandle. Rainfall amounts so far have been less than an inch, but radar estimated rainfall over the offshore waters show a core of 5 - 6 inches of rain associated with Ida's heaviest thunderstorms. Winds along the Gulf Coast of Mississippi, Alabama, and the Florida Panhandle were 20 - 35 mph this afternoon, and will steadily increase tonight as Ida draws near. Winds at the Mississippi Canyon buoy 150 miles south of Gulfport, MS were sustained at 65 mph at 1:40 pm EST, with 27 foot waves. This oil rig measures the wind at a height of 122 meters above the water, so one must reduce the winds by a factor of roughly 15% to correct the winds to the standard measurement height of 10 meters (see the journal article, GPS Dropwindsonde Wind Profiles in Hurricanes and Their Operational Implications, for more info on how to do corrections like this). This correction results in a surface wind speed of about 55 mph.


Figure 1. Long range radar out of Mobile, AL shows the eye of Ida, with the heaviest rains to the north side of the storm.

Infrared and visible satellite loops show that Ida has been holding on against high wind shear this afternoon, with heavy thunderstorm activity staying active in Ida's northern eyewall. Most of Ida's heavy thunderstorms have been displaced to the north of the storm, due to strong upper-level winds out of the southwest creating 35 knots of wind shear. Water vapor satellite imagery reveals a large area of dry air to the southwest of Ida, and the shear has now driven this dry air deep into the core of the storm, significantly disrupting it.

The intensity forecast for Ida
There is not much change to the intensity forecast for Ida. The high wind shear of 35 knots currently affecting the storm is forecast to increase to 40 knots early this evening, and 50 knots by midnight. With Ida now over waters near 26°C, which is barely enough to support a hurricane, and with water temperatures decreasing to 23°C near the coast, continued weakening is to be expected. However, Ida is beginning to transition to an extratropical storm (Figure 2). The spiral band on its east side no longer spirals around the storm, but instead hooks to the southeast like a giant comma, looking more like a front than a spiral band. It is often the case that during such a transition the winds will not die down much. I expect another bout of weakening will take Ida's top winds down to the 50 - 60 mph range along the coast tonight through Tuesday morning, though, since Ida is still partially tropical. Regardless of Ida's strength at landfall, the storm will be able to dump 4 - 8 inches of rain along the Gulf Coast and well inland. We can't rule out the possibility of an isolated tornado when Ida makes landfall, but the Storm Prediction Center Discussion maintains that the airmass in place over the Gulf Coast is relatively stable, and prospects for an appreciable severe weather threat appear low.


Figure 2. Afternoon satellite image of Ida, showing the classic signature of a tropical storm undergoing transition to an extratropical storm. There is heavy thunderstorm activity near the center, but the long band of clouds to the east of Ida doesn't look much like a spiral band--it looks more like a front.

The storm surge forecast for Ida
Tides are almost 4.0 above normal at Shell Beach, LA (on the east side of New Orleans) 2.0 feet above normal at Dauphin Island, AL, and 1.5 feet above normal at Pensacola, FL (Figure 3). NHC is calling for a storm surge of 3 - 5 feet above ground level, which is a reasonable forecast even if Ida weakens further. A large stretch of coast will be subject to very high water levels for an extended period of time today and tomorrow, with battering waves on top of the surge likely to cause a significant coastal erosion event.




Figure 3. Observed vs. predicted water levels at three coastal stations. Top: Shell Beach, LA (just east of New Orleans); middle: Dauphin Island, Alabama; bottom: Pensacola, FL. The green line shows how high above normal the water is. For Shell Beach, it was 3.6 feet above normal at 2 pm CST, 2.0 feet at Dauphin Island, and 1.5 feet at Pensacola. Image credit: NOAA Tides and Currents.

Comparing to Hurricane Kate
The last November hurricane in the Gulf of Mexico was Hurricane Kate. Kate struck the Florida Panhandle near Mexico Beach on November 21, 1985 as a Category 2 storm with 105 mph winds. According to Wikipedia, Kate killed five people in Florida and did $300 million (1985 dollars) in damage. Ida will cause relatively minor damage compared to Kate.

Links to follow:
U.S. Severe Weather Page
Wundermap for the Gulf Coast of Alabama.
Long-range radar out of New Orleans, LA.
Navarre Beach, FL webcam.
Coastal observations from the University of South Alabama.
Coastal observations from LSU.

Update on portlight.org charity errorts
The portlight.org disaster relief charity is gearing up to respond to any disaster needs from Tropical Storm Ida, and has sent a self-sufficient kitchen capable of serving 2000 meals per day to the Florida Panhandle region. They have another mobile kitchen ready to respond, if needed, as well as a truck filled with durable medical equipment and clinical/surgical supplies. Donations are welcome!

I'll have an update between 7 - 8 pm tonight.

Jeff Masters

Perdido Pass, Orange Beach, AL (OBA)
Admirals Quarters Condominium 1030 hrs CST- Light rain with occasional sheets; visibility reducing fast. Disappointed event has been downgraded to Tropical Storm.
Perdido Pass, Orange Beach, AL
Tropical depression IDA (DiegoSagrera)
Collapsed bridge Santa Cruz La Libertad
Tropical depression IDA

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: 559 - 509

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12Blog Index

559. DoubleAction
10. marraskuuta 2009 klo 01:16 (GMT)
Looks like florida will get more rain than anticipated, that line is getting closer, already getting some rain.
Member Since: 13.08.2008 Posts: 0 Comments: 159
558. winter123
10. marraskuuta 2009 klo 00:48 (GMT)
Quoting sammywammybamy:
WTF are the Models doing? there messed up.

the yellow line is not possible




That's the famous "bounce effect" publicized by wishcasters and doomcasters. It means when a storm touches land, it bounces off like a spinning top hitting a wall.
Member Since: 29.07.2006 Posts: 28 Comments: 1762
556. Raysfan70
10. marraskuuta 2009 klo 00:36 (GMT)
NEW BLOG!
Member Since: 28.07.2005 Posts: 138 Comments: 57354
555. CaicosRetiredSailor
10. marraskuuta 2009 klo 00:32 (GMT)
Quoting atmoaggie:

A small gradient wind feature not necessarily part of Ida's windfield and or a higher than usual inflow angle associated more with an extra-trop system than a TC?

Captured by the H*Wind analysis:


Gradients and pressure analysis show the potential for ENE winds here (though dated and with Ida not placed well):


I think the broader trough is taking over...and Ida isn't capable of true cyclostrophic winds to the NE.

(That took a while, my internet is flaky at the moment...uploads will not work)



Thanks for that ... it helps me understand what I am seeing with the winds.
Member Since: 12.07.2007 Posts: 0 Comments: 5984
554. MiamiHurricanes09
10. marraskuuta 2009 klo 00:30 (GMT)
NEW BLOG!
Member Since: 2.09.2009 Posts: 130 Comments: 21032
553. Skyepony (Mod)
10. marraskuuta 2009 klo 00:30 (GMT)
CIMSS has that blob NE of PR marked as an Invest, though I don't see it as such anywhere else yet. I called that as our probable next invest 4-5 days ago..
Member Since: 10.08.2005 Posts: 156 Comments: 36148
552. weatherwatcher12
10. marraskuuta 2009 klo 00:30 (GMT)
NEW BLOG
Member Since: 16.05.2009 Posts: 1 Comments: 1231
551. iluvjess
10. marraskuuta 2009 klo 00:28 (GMT)
Quoting atmoaggie:

A small gradient wind feature not necessarily part of Ida's windfield and or a higher than usual inflow angle associated more with an extra-trop system than a TC?

Captured by the H*Wind analysis:


Gradients and pressure analysis show the potential for ENE winds here (though dated and with Ida not placed well):


I think the broader trough is taking over...and Ida isn't capable of true cyclostrophic winds to the NE.

(That took a while, my internet is flaky at the moment...uploads will not work)


Awesome! Thanks for the explanation. First time dealing with the extra trpocal type. The winds all over the Gulf Coast East of Ida are all out of the North. Very interesting and thanks again.
550. AllyBama
10. marraskuuta 2009 klo 00:27 (GMT)
hmmm....did ya'll know that Dr. M has a new blog posted over 5 minutes ago?..lol
Member Since: 3.08.2006 Posts: 132 Comments: 20614
549. bjdsrq
10. marraskuuta 2009 klo 00:26 (GMT)
Quoting largeeyes:
Sounded from the NWS that the Carolina storm will be spawned from Ida, but won't actually be Ida....


"Ghost of Ida", or "Son of Ida"... you know, like Godzuki is the son of Godzilla.
Member Since: 26.07.2003 Posts: 3 Comments: 428
548. largeeyes
10. marraskuuta 2009 klo 00:25 (GMT)
THIS HAS
WEAKER AND MORE SUPPRESSED LOW DEVELOPING OFF GA/FL COAST WED
NIGHT-THU...DUE TO LIMITED PHASING OF GULF TROF/IDA REMNANTS AND NRN
STREAM TROF
Member Since: 22.08.2006 Posts: 0 Comments: 1449
547. weathermanwannabe
10. marraskuuta 2009 klo 00:24 (GMT)
Good Night Folks.
Member Since: 8.08.2006 Posts: 0 Comments: 8298
546. jipmg
10. marraskuuta 2009 klo 00:24 (GMT)
IDA is headed North east now towards Panhandle/alabama
545. atmoaggie
10. marraskuuta 2009 klo 00:24 (GMT)
Quoting iluvjess:
Atmo, can you offer an explanation as to why the wind in the NNE quadrant is out of the N and not the S or SE? TIA

A small gradient wind feature not necessarily part of Ida's windfield and or a higher than usual inflow angle associated more with an extra-trop system than a TC?

Captured by the H*Wind analysis:


Gradients and pressure analysis show the potential for ENE winds here (though dated and with Ida not placed well):


I think the broader trough is taking over...and Ida isn't capable of true cyclostrophic winds to the NE.

(That took a while, my internet is flaky at the moment...uploads will not work)
Member Since: 16.08.2007 Posts: 6 Comments: 12461
544. iluvjess
10. marraskuuta 2009 klo 00:23 (GMT)
Quoting largeeyes:
Sounded from the NWS that the Carolina storm will be spawned from Ida, but won't actually be Ida....


thanks for responding. Seems odd that the surface winds are out of the North and the flow of convection is out of the South.
543. Wetagain
10. marraskuuta 2009 klo 00:23 (GMT)
Lost power on dauphin island about an hour ago. refuse to crank gen yet. So the posts are not good from iPhone. But it's gotten me thru all day . I can assure you all that whatever the the indicated windspeed from bout data is every bit stated! Too bad it's dark, no pics. Be safe all.
542. winter123
10. marraskuuta 2009 klo 00:22 (GMT)
Quoting sammywammybamy:
LOOP OF IDA + BOC LOW FORMING INTO HYBRID IDA. NOTICE IN THE LAST COUPLE FRAMES THE BOC COMPLEX OF THUNDERSTORMS DESINGRATES INTO MERELY SHOWERS. IDA HAS SUCKED THE WELL ( BOC LOW). THAT MIGHT EXPLAIN WHY IDA HAS SUSTAINED ITS 70MPH WINDS.


wish that had the cancun radar on there too...
Member Since: 29.07.2006 Posts: 28 Comments: 1762
541. largeeyes
10. marraskuuta 2009 klo 00:21 (GMT)
Sounded from the NWS that the Carolina storm will be spawned from Ida, but won't actually be Ida....
Member Since: 22.08.2006 Posts: 0 Comments: 1449
540. nrtiwlnvragn
10. marraskuuta 2009 klo 00:20 (GMT)
Quoting iluvjess:
Well I guess nobody here has an explanation. Ususally the winds blow in a counter clocwise direction around the center and NE winds would generally be in the NW Quadrant. NE winds in East of the COC is very strange.


I can only offer this Link which shows a decaying High in western North Carolina.
Member Since: 23.09.2005 Posts: 13 Comments: 10468
538. tropicofcancer
10. marraskuuta 2009 klo 00:20 (GMT)
Quoting DestinJeff:


"i have a feeling about this one. reminds me of Opal, Erin, Andrew, Charley, Jeanne, Francis, Ivan, K, Wilma, Rita, Gustav, Ike"


ROFL Jeff, you know it's coming!!!
Member Since: 19.09.2006 Posts: 0 Comments: 141
537. aquak9
10. marraskuuta 2009 klo 00:19 (GMT)
Quoting bjdsrq:


18Z GFS says this turns into a bigger sized storm when it pops out your way along the eastern US. Tropical transformed to Nor-easter?!! Is Ida a cross-dresser? lol


From JAX NWS:

THURSDAY...LOW OFF THE FLORIDA COAST WILL SLOWLY DRIFT SOUTHEAST
TOWARD THE BAHAMAS AND ONLY SCATTERED LIGHT RAIN SHOWERS WILL LINGER
ACRS THE FORECAST AREA..

ok, now i am so confused....what are they talking about? i thought the low was supposed to head north, transitioning into a decent nor'easter?
Member Since: 13.08.2005 Posts: 163 Comments: 25507
536. thelmores
10. marraskuuta 2009 klo 00:19 (GMT)
Quoting sammywammybamy:
WTF are the Models doing? there messed up.

the yellow line is not possible


Quoting fishwishin:
I guess I'm the only one watching TWC? Jim Cantore said about 5 minutes ago that he is being told that Ida has taken a more easterly jog.


Yea well, depends on the "eye of the beholder! And depends on "what the definition of is" is! LOL
Member Since: 8.09.2005 Posts: 0 Comments: 3788
535. gordydunnot
10. marraskuuta 2009 klo 00:19 (GMT)
If you think that yellow circle makes it much farther west, then even close to the Bahamas I've got land for you in everglades national park. Caveat unless it does a couple loops first.
Member Since: 18.08.2008 Posts: 0 Comments: 3109
534. StormSurgeon
10. marraskuuta 2009 klo 00:19 (GMT)
Look at the rain!

Rain
Member Since: 1.09.2007 Posts: 0 Comments: 1793
533. weathermanwannabe
10. marraskuuta 2009 klo 00:19 (GMT)
Quoting LACajunKid:


I'm in NW Tally, weatherman. Same thing up here. No rain at all, even though the satellite has been showing a big green blob over us most of the day.


Yup; If you only looked at the loops ad didn't live here, you would think it's been pouring here all day. Glad to see the system weakening and looks like we dodged a bullet in terms of tornadic activity. Guess my kid will be marching ater all in the Veteran's Day Parade on Wednesday.
Member Since: 8.08.2006 Posts: 0 Comments: 8298
531. bjdsrq
10. marraskuuta 2009 klo 00:18 (GMT)
Quoting DestinJeff:
T-minus 5, 4, 3, ... until someone latches on to the GFS model and suggests regeneration in the NW gulf on its way to west coast of FL


What GFS run? The 18Z GFS I'm looking at runs it out over the SE US into the atlantic and makes a noreaster out of it.

http://moe.met.fsu.edu/tcgengifs/
Member Since: 26.07.2003 Posts: 3 Comments: 428
529. iluvjess
10. marraskuuta 2009 klo 00:17 (GMT)
Look at the winds N and E of the center...

Link
528. HaboobsRsweet
10. marraskuuta 2009 klo 00:16 (GMT)
daulphin island showing 40G53
Member Since: 20.05.2009 Posts: 0 Comments: 1640
527. jipmg
10. marraskuuta 2009 klo 00:16 (GMT)
temps are in the 60S were ida is making landfall???
526. SouthALWX
10. marraskuuta 2009 klo 00:16 (GMT)
models are tracking the LLC which could easily be left behind.. After the initial landfall (now) Ida will be dead for all intents and purposes.
edit: do note I'm talking of Ida as a tropical system .. its' top can and probably will bbecome an east coast windstorm.
Member Since: 27.08.2008 Posts: 0 Comments: 1497
525. LACajunKid
10. marraskuuta 2009 klo 00:15 (GMT)
Quoting weathermanwannabe:
For whatever this is worth, only a dark cloud deck in Tallahassee all afternoon, mild winds, and a few patches of very light rain (don't be fooled by the "look" of the Satt Loops) so far. Tommorow may be quite different as the low turns toward us but so far so good.


I'm in NE Tally, weatherman. Same thing up here. No rain at all, even though the satellite has been showing a big green blob over us most of the day.
523. StormSurgeon
10. marraskuuta 2009 klo 00:14 (GMT)
Quoting DestinJeff:
T-minus 5, 4, 3, ... until someone latches on to the GFS model and suggests regeneration in the NW gulf on its way to west coast of FL


Destin? What?
Member Since: 1.09.2007 Posts: 0 Comments: 1793
522. BurnedAfterPosting
10. marraskuuta 2009 klo 00:14 (GMT)
Quoting sammywammybamy:


How are you Oz.

A Dissaponited Season for many.Ends in a Suppriseing twist

Even in the Beginneing people clamied it would be 0,0,0

With 21 days (about) left of the hurricane season

Its seems we shall all look forward to next season for the joys and thrills of hurricanes.


did you not see the yellow circle NE of the Islands? Season may not be over just yet
521. fishwishin
10. marraskuuta 2009 klo 00:14 (GMT)
I guess I'm the only one watching TWC? Jim Cantore said about 5 minutes ago that he is being told that Ida has taken a more easterly jog.
Member Since: 25.09.2007 Posts: 0 Comments: 41
520. StormSurgeon
10. marraskuuta 2009 klo 00:13 (GMT)
Quoting CycloneOz:
Good Evening! :)


Hey!
Member Since: 1.09.2007 Posts: 0 Comments: 1793
518. CaicosRetiredSailor
10. marraskuuta 2009 klo 00:13 (GMT)
Dagnabit!

Here I am watching Ida and now I look over my shoulder and see a yellow circle.
(a circle where Kate formed later than this in Nov. 85)

Member Since: 12.07.2007 Posts: 0 Comments: 5984
517. pcolasky
10. marraskuuta 2009 klo 00:13 (GMT)
Hate it when the storms roll through at night!
516. BurnedAfterPosting
10. marraskuuta 2009 klo 00:11 (GMT)
Quoting sammywammybamy:
WTF are the Models doing? there messed up.

the yellow line is not possible




Its tropical weather; ANYTHING is possible lol
515. gordydunnot
10. marraskuuta 2009 klo 00:11 (GMT)
How could the models not be possible when people are telling you the wind is out of the north when its not suppose to be.
Member Since: 18.08.2008 Posts: 0 Comments: 3109
513. jipmg
10. marraskuuta 2009 klo 00:11 (GMT)
lol looks to me like the system is moving North east now..
512. bjdsrq
10. marraskuuta 2009 klo 00:10 (GMT)
Quoting thelmores:
wish we could get some rain in the Carolina's!


18Z GFS says this turns into a bigger sized storm when it pops out your way along the eastern US. Tropical transformed to Nor-easter?!! Is Ida a cross-dresser? lol
Member Since: 26.07.2003 Posts: 3 Comments: 428
511. Orcasystems
10. marraskuuta 2009 klo 00:10 (GMT)
Blog Update

AOI

AOI
Member Since: 1.10.2007 Posts: 81 Comments: 26493
510. iluvjess
10. marraskuuta 2009 klo 00:10 (GMT)
Well I guess nobody here has an explanation. Ususally the winds blow in a counter clocwise direction around the center and NE winds would generally be in the NW Quadrant. NE winds in East of the COC is very strange.
509. thelmores
10. marraskuuta 2009 klo 00:10 (GMT)
Quoting atmoaggie:

Don't let the movement of the convection going in the sheared direction fool you as to COC movement...


Hey, I was looking at the storm center on Radar...... wasn't even paying attention to the convection........

Link

Looks NNE to me, certainly east of due north!..... but I don't think its worth arguing...... looks like landfall in Mobile Bay to me......


Looks like the NHC has designated a "new area" to watch......

Member Since: 8.09.2005 Posts: 0 Comments: 3788

Viewing: 559 - 509

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12Blog 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

Partly Cloudy
43 °F
Puolipilvistä