ATL : TROPICAL DEPRESSION IDA

[brunota2003]

I would bring it in just encase...that way if y'all do get nasty winds, dont have to worry about them breaking or becoming airborne debris (Debris! Dusty, we have debris!)

[Chris_in_Tampa]

For several of the last NOAA HDOBs, the lat and lon of the plane have not been moving.

[Rainband]

Stil expanding on the West and Northwest side

it's expanding everywhere check your pms

[baygirl_1]

With this whole shift to the east thing (I am in Mobile, AL), I am wondering if I should still get my patio furniture and all of that in tonight or not. I won't have time to do it tomorrow (if Ida does come our way) because I will have to help secure my work and then my grandmother's house.

Soooo, what is the thought of Ida shifting back to the west or shifting MORE east?

Decisions, decisions...

probably cause its going to be windy either way..

haha..I know that much! I just wondered what the thought was of shifting the track...if people (especially you because I value your opinions) thought it would shift back to the west or shift more easterly? That way I could make my decision on getting everything in at my own house (while I can)!

We decided to err on the side of caution--- our stuff is in and secured.

[brunota2003]

"You have now entered...The Twilight Zone."

[ozonepete]

I'm still amazed it's that strong based on the presentation but earlier today it looked like a eye was appearing before deep convective tops obscured it again. This is probably the most interesting part of the 2009 Atlantic Hurricane season for me.

Yeah, you said it. A cat 2 that never had a clear eye on the conventional satellites. Very rare, but understandable with the southerly shear blowing the cirrus over the eye the entire time.

[Ivanhater]

She will keep her NW to NNW motion for the next few hours until the high shifts

[MGC]

Yea, Ida is the uggliest Cat-2 I've seen in a while.....MGC

[jlauderdal]

We decided to err on the side of caution--- our stuff is in and secured.[/quote][/quote][/quote]

well that has to be the fastest hurricane preparation ever, i think you spent more time contemplating the decision than actually doing the work...

[IvanSurvivor]

Evening update from Dr. Jeff Masters:

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

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.

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.

I'll have an update Monday morning.

Jeff Masters

So is this saying that tides will be 3-5 ft above normal and then a surge of up to 6 ft on top of that? If so, I may have a problem. There are a lot of us that are still at 7.5-8 ft elevation.

[Derek Ortt]

Dr. Masters is incorrect about the pressure rising. He must have missed the very high surface winds that were recorded via the dropsonde.

The dropsonde from the latest pass through the eye will be critical

[Dave]

URNT15 KNHC 082331
AF309 0411A IDA HDOB 54 20091108
232330 2336N 08717W 6976 03141 0061 +084 +067 090032 033 035 000 00
232400 2338N 08719W 6966 03155 0062 +082 +067 090033 034 032 000 00
232430 2339N 08721W 6970 03151 0065 +080 +065 092032 034 029 000 00
232500 2340N 08723W 6966 03150 0067 +079 +063 088033 033 030 000 00
232530 2341N 08724W 6967 03156 0073 +077 +062 087030 033 028 001 00
232600 2343N 08726W 6967 03158 0070 +081 +060 088029 030 028 000 00
232630 2344N 08728W 6969 03154 0074 +080 +057 091031 032 028 001 00
232700 2345N 08730W 6964 03160 0075 +078 +056 094030 032 028 000 00
232730 2346N 08732W 6970 03152 0076 +078 +055 092030 031 029 000 00
232800 2348N 08734W 6967 03161 0077 +077 +054 094030 031 028 000 00
232830 2349N 08735W 6967 03159 0076 +077 +054 096032 034 026 001 00
232900 2350N 08737W 6970 03155 0078 +077 +053 095032 033 027 000 00
232930 2351N 08739W 6967 03157 0076 +077 +053 097032 033 026 001 00
233000 2353N 08741W 6966 03160 0082 +074 +052 098035 036 027 001 00
233030 2354N 08743W 6964 03163 0098 +063 +051 098037 039 028 003 00
233100 2355N 08745W 6967 03157 0094 +067 +049 098032 035 030 001 00
233130 2356N 08746W 6968 03162 0083 +076 +045 096026 028 030 005 00
233200 2357N 08748W 6968 03158 0085 +075 +043 103026 026 025 001 00
233230 2359N 08750W 6884 03257 0082 +071 +042 102025 026 021 000 00
233300 2400N 08752W 6620 03583 0082 +052 +041 103019 020 020 000 00
$$
;

[Ivanhater]

Wave forecast

[Dave]

000
UZNT13 KNHC 082331
XXAA 58237 99229 70864 08126 99989 24400 36059 00597 ///// /////
92584 20200 03093 85313 17200 05103 70962 08641 09051 88999 77999
31313 09608 82302
61616 AF309 0411A IDA OB 30
62626 EYEWALL 360 SPL 2285N08653W 2307 MBL WND 01078 AEV 20801 DL
M WND 05579 989698 WL150 36069 089 REL 2290N08643W 230241 SPG 228
7N08653W 230701 =
XXBB 58238 99229 70864 08126 00989 24400 11942 20800 22850 17200
33726 13400 44715 13021 55698 08044
21212 00989 36059 11965 01082 22945 01579 33935 02600 44917 03087
55900 04099 66869 05093 77850 05103 88793 08088 99765 07604 11753
09093 22711 08068 33698 09049
31313 09608 82302
61616 AF309 0411A IDA OB 30
62626 EYEWALL 360 SPL 2285N08653W 2307 MBL WND 01078 AEV 20801 DL
M WND 05579 989698 WL150 36069 089 REL 2290N08643W 230241 SPG 228
7N08653W 230701 =

[Dave]

000
URNT12 KNHC 082332
VORTEX DATA MESSAGE AL112009
A. 08/23:04:40Z
B. 22 deg 47 min N
086 deg 25 min W
C. 700 mb 2948 m
D. 80 kt
E. 355 deg 4 nm
F. 099 deg 103 kt
G. 359 deg 8 nm
H. 980 mb
I. 7 C / 3069 m
J. 17 C / 3054 m
K. 7 C / NA
L. OPEN E
M. C8
N. 12345 / 7
O. 0.02 / 1 nm
P. AF309 0411A IDA OB 29
MAX FL WIND 108 KT NE QUAD 22:09:20Z
HAIL AND CONT LIGHTNING N QUAD
;

[cycloneye]

Below is a chart of when the high tides will be during landfall somewhere in the gulf coast.

[Aric Dunn]

Dr. Masters is incorrect about the pressure rising. He must have missed the very high surface winds that were recorded via the dropsonde.

The dropsonde from the latest pass through the eye will be critical

thats why i was wondering what time that was posted.. there were some errors but nothing major..

[JonathanBelles]

HAIL AND CONT LIGHTNING N QUAD

That generally says intensification to me. Correct?

[brunota2003]

Indeed...those two are rarely seen...let alone together. Wilma is a good example

[Dave]