New computer model runs for Katrina

By: Dr. Jeff Masters , 7:11 PM GMT on August 25, 2005

Share this Blog
0
+

The 1:18pm EDT Hurricane Hunter mission found the pressure of Katrina remained constant at 990mb, but the maximum winds were now on the northwest side at 64 knots (73 mph) at the airplane's flight level of 5000 feet. Radar from Miami confirms that the north side of Katrina has greatly increased in the amount and intensity of precipitation the past two hours as the storm continues to strengthen. It is a very good thing that Katrina does not have an extra 12 hours to intensify before landfall! However, the very favorable environment for intensification that Katrina is currently in is expected to still exist once she is in the Gulf of Mexico Saturday. I expect Katrina will become at least a Category 2 hurricane before its second landfall.

The latest computer model runs, performed using the 8am EDT upper air data, have made a major shift. Katrina is expected to push much farther west off of the western coast of Florida, and make a delayed turn to the north. These latest model runs show a much reduced risk to Tampa, and put an area from New Orleans to Cedar Key, Florida at risk. In the center of this risk area lies the U.S.'s very own hurricane magnet, the Pensacola region, where Ivan and Dennis struck.

Katrina continues to intensify at a modest pace, and if present trends continue will hit Florida near Fort Lauderdale tonight as a minimal Category 1 hurricane with 75 - 80 mph winds. The northwest side of the storm continues to suffer from dry air intrusions, and the primary intense thunderstorms and strongest winds are on the south side. Thus, the usual rule about the right front quadrant (north side) of the storm being the most dangerous is not neccesarily the case with Katrina. The highest storm surge will still be to the north of where the center comes ashore, but wind damage may be equally distributed on both sides of the storm.

The Miami radar loop continues to show an increase in low-level banding, and an eye-like feature trying to form. Upper level outflow is improving and slowing expanding.

As I discussed in the previous blog entry, the major threat to South Florida from Katrina is freshwater flooding from her rains. Rainfall amounts of 6 - 10 inches are expected from this slow-moving storm. For comparison, Hurricane Irene of 1999, which hit South Florida as a Category 1 hurricane, dumped 10 - 20 inches of rain. Damage from Irene was over $800 million in Florida. Damage from Katrina will probably be much lower, in the $30 - $100 million range, since Katrina's rainfall will be half of what Irene's was.

What's that behind Katrina?
A large area of disturbed weather even bigger than Katrina lies to her east, just north of Hispanolia. This disturbance lies in an area of high wind shear of 25 - 35 knots, and is not a threat to develop into a tropical depression in the next few days.

Katrina blogs
For observations of what's happening now in South Florida, we have several bloggers writing today:

turtlehurricane (Weston, Broward County)

sngalla (Fort Lauderdale)

MrJ76 (Okeechobee)

Zeenster (Cape Coral, SW Florida)

evolution (Charlotte Harbor, SW Florida)

Dr. 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: 1192 - 1142

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24Blog Index

1192. noshoes
10:22 PM GMT on August 28, 2007
I am late getting here...and there is no way I will ever catch up on all the posts of the day. Are we going to be "reliving" Katrina all night?
Thanks.
Member Since: July 17, 2006 Posts: 0 Comments: 24
1191. palmbeacher
3:30 PM GMT on August 26, 2005
100MPH sustained 122MPh gusts. Cat 2, Pressure is dropping. Will be a 3 when it hits panhandle.
1190. leftyy420
3:05 PM GMT on August 26, 2005
good morning
Member Since: August 24, 2005 Posts: 35 Comments: 1987
1189. Raysfan70
12:39 PM GMT on August 26, 2005
thanxs
Member Since: July 28, 2005 Posts: 138 Comments: 57354
1188. wxgssr
12:33 PM GMT on August 26, 2005
Raysfan...a lot will depend on how the low and trof tracks after it tracks to the E of the northern ridge axis. IF it starts t odig..will pick her up and we will see teh big hook. If it does not dig as much and the ridge maintains more than the modles are going for...she will tack further W. Gotta head to work...i'll be watching...not posting though.
1187. Raysfan70
12:20 PM GMT on August 26, 2005
I don't think a direct hit but I am worrying about it skirting the coast closer then what they think and that could be alot worse for us.

Does anyone see any weakness happening as of yet?
Member Since: July 28, 2005 Posts: 138 Comments: 57354
1186. SherryB
12:18 PM GMT on August 26, 2005
Thanks for your opinions guys...I guess its all a waiting and watching game now...This can be addicting..I have been letting a whole lot of things fall by the wayside from watching this storm but heck I can't help myself...I guess I am a meteorologist wanna be..

1185. nash28
12:17 PM GMT on August 26, 2005
We absolutely could see something out of this. I don't think a direct hit is possible since there is nothing in the atmosphere that would cause the storm to hook that far to the right, but as I was telling my wife last night, I believe this storm will still skirt the coast and we will be within 100 miles of the center.
Member Since: July 11, 2005 Posts: 190 Comments: 16972
1184. Raysfan70
12:17 PM GMT on August 26, 2005
This is what is scary me. I am not good at loking at all the ridges and all so I do not understand any of that.
Member Since: July 28, 2005 Posts: 138 Comments: 57354
1183. wxgssr
12:15 PM GMT on August 26, 2005
I think the longer it heads SW and W the better for the Florida peninsula as a whole and particularly Tampa southward(duh, that is stating the obvious, but its true). Entire peninsula will be udner the threat of easter periphery feeder bands...Especially this afternoon with the heating. I really don't see a landfall that would directly threaten Tampa-Orlando-Daytona corridor.
1182. nash28
12:14 PM GMT on August 26, 2005
I believe the timing of that weakness in the ridge is crucial. If she slows much more, that weakness could develop while she is not too far west of the peninsula. If she picks up forward speed, she will move farther west before turning. I am one who is saying we are not by any means out of the proverbial woods.
Member Since: July 11, 2005 Posts: 190 Comments: 16972
1181. Raysfan70
12:12 PM GMT on August 26, 2005
NAsh i am one of them Tampa Bay people, do you think that there is a chance that we could see something out of this?
Member Since: July 28, 2005 Posts: 138 Comments: 57354
1180. nash28
12:10 PM GMT on August 26, 2005
I don't think Tampa Bay is out of the woods yet. All of our local meteorologists are already talking as if the hurricane were 400 miles west of us already.
Member Since: July 11, 2005 Posts: 190 Comments: 16972
1179. SherryB
12:09 PM GMT on August 26, 2005
So still a chance of it moving across the State of FL is what you are saying nash and wxgssr? I live between Orlando and Daytona. Do you think there is a need for me to be concerned? As for forecasts, as I stated yesterday, after living through Charley last year, I don't believe them until landfall..LOL
1178. Raysfan70
12:08 PM GMT on August 26, 2005
The news here seems to really think that we are out of it now.
Member Since: July 28, 2005 Posts: 138 Comments: 57354
1177. Raysfan70
12:08 PM GMT on August 26, 2005
Jedkins you still think that we need to watch this storm?
Member Since: July 28, 2005 Posts: 138 Comments: 57354
1176. Jedkins
12:03 PM GMT on August 26, 2005
Homestead had 10 inches from the center alone in a couple hour time!
1175. wxgssr
12:03 PM GMT on August 26, 2005
My observations this am. Storm has a little weakness in the N quadrant of the eye, movement is to the SW(the main circ, the dry area in N quadrant can be a bit misleading imo), anchor lo over Central canada is moving rapidly E, and a major sw trof rotated around the low thru the N rockies, and looks to be now moving E without much digging SE at all. Western periphery of the ridge over SE/Cent US still looks to be holding its own, and the ridge may actually build a bit NW as a SW trof/ridge couplet moves thru the flow between the deep LW trof well off the Pacific Coast and the SE/Cent US ridge towards the Canadian low. My bottom line, its still way too early to rally pinpoint a landfall, and small variances in the overall North America dynamics can and WILL make a big difference in where katrina comes ashore again. Nobody is out of the woods yet at all...but the longer she heads SW, the better for the Florida west coast as far as a direct impact. Feeder bands are going to rake the Florida Peninsula all day though...
1174. Jedkins
12:01 PM GMT on August 26, 2005
There is a chance the NWS said untill the center is literally due west of tampa we still have to watch it it.
1173. nash28
11:54 AM GMT on August 26, 2005
Well, I've seen the ridge over Texas build up very strong, but I can't help but think it is going to shift west sooner than the models are figuring. I don't think Katrina will make a sharp Charley hook, but I really think the Big Bend area of Florida is at risk here.
Member Since: July 11, 2005 Posts: 190 Comments: 16972
1172. TotalDestruction
11:50 AM GMT on August 26, 2005
Lol @ LADobeLady
1171. wxgssr
11:47 AM GMT on August 26, 2005
Yes...just as there is a chance that it will not turn as quickly putting areas farther west over to and including SE LA more at risk. Pay attention, prepare now while you still can. Dry foods and bottled water won't go bad...you will use the full tank of gas in your car anyway, and you can always take boards back down off your house.
1170. nash28
11:44 AM GMT on August 26, 2005
Any chance this thing makes the northward turn sooner putting the west coast of florida at more risk??
Member Since: July 11, 2005 Posts: 190 Comments: 16972
1169. LADobeLady
11:39 AM GMT on August 26, 2005
Oh brother Canada is going to love us if we evacuated the whole U.S. and head North. lol
Member Since: July 29, 2005 Posts: 21 Comments: 794
1168. TotalDestruction
11:31 AM GMT on August 26, 2005
Based on StormFlops predictions the whole USA needs to be evacuated! :S
1167. SherryB
11:23 AM GMT on August 26, 2005
Morning all..I agree..Hope the models are on track as well (not that I want ANYONE to have to go through that) but I am sure hoping there is no major shift to the east but I guess only time will tell us that huh?
1166. LADobeLady
11:18 AM GMT on August 26, 2005
Good morning!

I hope the models are right on track, if Katrina should move more west and God forbid actually do what Stormtop says we'd have major problems here in LA it takes us 3 days to evacuate and there simply wouldn't be time. I-10 W becomes a parking lot during evacuations.
Member Since: July 29, 2005 Posts: 21 Comments: 794
1165. hookedontropics
11:02 AM GMT on August 26, 2005
The current models seem to be right on to this point
Member Since: August 25, 2005 Posts: 3 Comments: 127
1164. boiredfish
11:01 AM GMT on August 26, 2005
If Katrina moves much more to the west we're gonna start getting nervous in Galveston...
Member Since: July 8, 2005 Posts: 0 Comments: 442
1163. hookedontropics
11:00 AM GMT on August 26, 2005
She is going due west now.
Member Since: August 25, 2005 Posts: 3 Comments: 127
1162. steelmagnolia44
10:46 AM GMT on August 26, 2005
A word about STORMTOPS posts.....

I think it is important to have everyone's point of view about this potentially dangerous storm. Those of you with the education and experience can evaluate all the fine points in the data and have a legitimate debate. Those of us depending on accurate info need to hear all the opinions - including STORMTOPS.

I live in the Pass Christian area. I remember Camille. As the adjuster said - Camille left slabs, and steps where a home once stood. Relatives of a friend of mine were found dead in a their neighbor's driveway because they did not heed the warnings and leave. If any one of you is even thinking another Camille, I, for one, want to know! There is not much time. I am beginning my serious preparations TODAY.

Over the years, I have observed that storms do not follow the NHC center line track. They go to either side of it.

Thinking of our friends in Florida this morning.......
Member Since: August 24, 2005 Posts: 0 Comments: 43
1161. nola
10:42 AM GMT on August 26, 2005
My apologies to Dr. Jeff. Woke up and speed clicked to read latest comments before 1st cup of coffee and accidentally "flagged" whole blog as "obscene". Now - gotta read and see if I should batten down or run for the hills...
1160. hookedontropics
10:41 AM GMT on August 26, 2005
Anyone see the free video from Joe Bastardi. It is a bit old, but damn he is good
Member Since: August 25, 2005 Posts: 3 Comments: 127
1159. Weareallgunnadie
10:18 AM GMT on August 26, 2005
Yep, here in Panama City Beach...once again, looks like I may be boarding up.
1158. Carbo04
9:42 AM GMT on August 26, 2005
lol, that's terrible. I wasn't trying to say it would get to CAT 5. I don't think it will, just saying it has a chance with 90 degree water ahead of it.
1157. TotalDestruction
9:27 AM GMT on August 26, 2005
Or....

...maybe even a CAT 6 (according to StormFlop)!
1156. Carbo04
9:03 AM GMT on August 26, 2005
Possibly even a CAT 5 if it moves westward enough before it goes north.
1155. Carbo04
9:02 AM GMT on August 26, 2005
Already a hurricane again. I believe 100% we'll see a CAT 4 hitting Florida, Monday.
1154. aquak9
8:52 AM GMT on August 26, 2005
Lefty??!! you gotta get some sleep! an exhausted brain DOES NOT run so very well, and many people will be looking for your input today...no one is superman so please go get a few zzz's
Member Since: August 13, 2005 Posts: 177 Comments: 26628
1153. bekroweather
8:51 AM GMT on August 26, 2005
Katrina again a hurricane!
1152. TotalDestruction
8:26 AM GMT on August 26, 2005
It's the eye of destruction...! Woohoo!

Armageddon time!
1151. bekroweather
8:16 AM GMT on August 26, 2005
It looks to me that she is creating an outer eye wall Halon.
1150. Halon056
8:07 AM GMT on August 26, 2005
Did I detect a wobble???? and only a wobble???
Member Since: July 16, 2005 Posts: 0 Comments: 349
1149. Valence
8:05 AM GMT on August 26, 2005
Kat -

Dont be afraid to go to a shelter either. Its not a matter of pride, its survival. Im getting the same bad feeling I had last year with Charlie. Thank god he went futher N, or I may not be tying this right now.

Adios.
1148. Katrina3
8:00 AM GMT on August 26, 2005
Can't evac. not enough cash...
We board up and have more botteled water and canned goods that any one person should have. Aslo borrowing a generator this go around.
Panama City is inbetween Pensacola and Apalachicola.
I'll be on here during the storm for as long as the cable holds. Thanks for the warning though.
Kat
1147. Valence
8:00 AM GMT on August 26, 2005
And Lefty:

Go to bed too . . . I want you to be conscious when im on here tomorrow. Assuing I can keep power when she makes her turn.

Im really off to bed now.

JV
1146. Randyman
7:59 AM GMT on August 26, 2005

Tropical Storm Katrina Now in the Southeastern Gulf of Mexico

Issued: 2:45 AM CDT Friday, August 26, 2005


At 3AM CDT Friday, Tropical Storm Katrina will be near 25.3N/81.4W, or 55 miles north-northeast of Key West, Florida. Katrina is moving to the west-southwest at 10 mph. Maximum sustained winds are 70 mph, with gusts to 95 mph. Central pressure is 990 millibars or 29.23 inches.


Katrina has temporarily weakened to just below hurricane strength as it has moved across southern Florida. However, Katrina should quickly regain hurricane strength within the next few hours. We expect Katrina to begin moving more northwesterly over the next 24-36 hours, followed by a turn to a more northerly path after that.


Katrina will likely become a major Category three hurricane before it makes landfall early Monday morning in the Florida Panhandle. In fact, Katrina might become a strong Category three or possibly a Category four hurricane before that next landfall.


For further details on Katrina, please see your ImpactWeather Storm Commentary and Forecast Track below.


Meteorologist: George Harvey
Member Since: July 26, 2005 Posts: 0 Comments: 222
1145. Valence
7:58 AM GMT on August 26, 2005
Since Frances and Jeanne oficially made landfall at the same place (Stuart, FL), why not this one too?

Since all of these storms seem to double (or triple) bullseyes, im just wondering what wave from the Carribean is going to end up on my doorstep here in Ft. Myers.

JV
1144. leftyy420
7:56 AM GMT on August 26, 2005
thats my feeling anywhere the panama city to the fl,miss,al border is a good bet
Member Since: August 24, 2005 Posts: 35 Comments: 1987
1143. leftyy420
7:55 AM GMT on August 26, 2005
kat ur right in the path. i would take all precautions and evacute when prompted to. this will be a hurricane to remeebr
Member Since: August 24, 2005 Posts: 35 Comments: 1987
1142. Valence
7:54 AM GMT on August 26, 2005
I personally think the storm is going to end up a little farther West that the current model consensus, that we'll see a slight shift in the track to the west at each update.

Im thinking closer to the AL/FL border (which, as some people have forgotten, is where Ivan oficially came ashore). But thats just a gut feeling. Anyway you look at, the FL panhandle is in for another shot. I just hope Katrina intensifies so quickly that she can't hold it and weakining as she moves onshore, instead of strengthing.

Anyway, im off to bed . . . i have to be up in 5 hours.

JV

Viewing: 1192 - 1142

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24Blog 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
28 °F
Overcast

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron