ATL GUSTAV: Tropical Depression - Discussion

[Sihara]

IF NEED BE, Louisiana officials are saying they are prepared to begin contraflow on Saturday in the New Orleans metropolitan area. With Houma metro and New Orleans metro, including surrounding areas, the total number of people that would need to evacuate would be close to 1.7 million people.

Sean, is "contraflow" the same thing as reverse-laning? And if they do have to evacuate all those people, will they be able to avoid a Rita-like traffic debacle? The idea of this storm clobbering New Orleans is really too awful to contemplate.

Another question for any met or knowledgable person - this morning there was some discussion of a front dipping down into the gulf and influencing the future track of Gustav. Is this still a possibility, or was that the "weakness" that doesn't seem as likely now? (sorry, trying to catch up after a long day at work, away from S2k.)

[Weatherfreak000]

Im gonna sit on this and wait until the next run of models, see if a trend persists..


The GFDL and HWRF have been so adamant on their tracks...I would like to see that change.

[HarlequinBoy]

All twenty relatives I have in New Orleans and around Biloxi have pretty much agreed to drive up Sunday morning if the cone stays about the same. I think it's encouraging they are already well aware and planning to leave if need be.

[Ivanhater]

I dont know wxman...seems most of the models do get this through the weakness, but very uncertain right now..GFS, nogaps, gfdl, hwrf...though if the 18z and 00z runs shift west, I think they may be on to it not finding the weakness...

[KWT]

Well thats the key thing that wxman57, everyone has to pay real attention to this system, the models to seem to be slowly shifting towards each other, GFDL slowly shifting westward whilst the ECM/UKMO have made rather large jumps north over the last few runs and I think they will probably meet in the middle over Texas.

what is looking less likely is a Yucatan hit and if it does go through the channel then whilst its inflow will probably get disrupted if its still a small hurricane then disruption won't really occur.

Wxman57 if it goes on your track rather then NHC any roug ideas on possible strength, I presume we are talking about a major hurricane?

[O Town]

For those members that haved not seen this radar from Eastern Cuba,you can see the center of Gustav emerging the Hatian coast.

Unable to see an image Luis. Can you pass along the link. Thx.

[Wx_Warrior]

EURO also develops a system east of Florida.

[Sean in New Orleans]

IF NEED BE, Louisiana officials are saying they are prepared to begin contraflow on Saturday in the New Orleans metropolitan area. With Houma metro and New Orleans metro, including surrounding areas, the total number of people that would need to evacuate would be close to 1.7 million people.

Sean, is "contraflow" the same thing as reverse-laning? And if they do have to evacuate all those people, will they be able to avoid a Rita-like traffic debacle? The idea of this storm clobbering New Orleans is really too awful to contemplate.

Another question for any met or knowledgable person - this morning there was some discussion of a front dipping down into the gulf and influencing the future track of Gustav. Is this still a possibility, or was that the "weakness" that doesn't seem as likely now? (sorry, trying to catch up after a long day at work, away from S2k.)

One of the things many do not know about Hurricane Katrina, was that it was the quickest most successful evacuation of 1.3 million people in the history of the United States. We learned from Ivan. I'm sure Texas learned from the Rita disaster. Agreements are in place for both sides of all interstates leaving the New Orleans area for both sides of the interstate to be moving in one direction (out of the city) upwards of 150 miles into the State of Mississippi. It is really a model reverse laning plan. Here's hoping that we won't have to utilize that plan. A New Orleans hit would be tragic, but, measures are in place where I doubt the City would have major flooding, at all. Now what it would do to the still-fragile populace is another thing, but, we are notoriously tough.

[cycloneye]

For those members that haved not seen this radar from Eastern Cuba,you can see the center of Gustav emerging the Hatian coast.

Unable to see an image Luis. Can you pass along the link. Thx.

Oh some cant see the image,so here is the link.

http://www.insmet.cu/asp/genesis.asp?TB ... B1=RADARES

[KWT]

I dont know wxman...seems most of the models do get this through the weakness, but very uncertain right now..GFS, nogaps, gfdl, hwrf...though if the 18z and 00z runs shift west, I think they may be on to it not finding the weakness...

I think the NHC track looks pretty solid right now to be honest, I think the models you talk of will shift a touch further west but we shall see.

A nice big convective burst south of Haiti has just gone up, not over the center of Gustav but a good sign of what will happen once Gustav gets away from Haiti further I feel.

[wxman57]

Well thats the key thing that wxman57, everyone has to pay real attention to this system, the models to seem to be slowly shifting towards each other, GFDL slowly shifting westward whilst the ECM/UKMO have made rather large jumps north over the last few runs and I think they will probably meet in the middle over Texas.

what is looking less likely is a Yucatan hit and if it does go through the channel then whilst its inflow will probably get disrupted if its still a small hurricane then disruption won't really occur.

Wxman57 if it goes on your track rather then NHC any roug ideas on possible strength, I presume we are talking about a major hurricane?

Makes no difference as far as possible intensity. Not much wind shear or ice cold water anywhere in the Gulf.

[KWT]

So then in other words the only thing regulating strength would be EWRC, well thats pretty much confirmed the chances of a major then it seems, just hope it isn't as strong as the GFDL suggests on its 12z run!

[HURAKAN]

[O Town]

Not very impressive on radar, I would have thought there would be alot more rain associated with it.
I guess thats a good thing for Haiti.

[Annie Oakley]

State of Texas issues first situation report:

ftp://ftp.txdps.state.tx.us/dem/sitrep/ ... 082608.pdf

Texas is great, they don't mess around and they take responsibility for their actions

Texas SALUTES Oklahoma! Yes, we stand ready and prepared...

[CrazyC83]

Still has a well-defined eye on radar, so I would set it at 65 kt right now.

[HarlequinBoy]

Not very impressive on radar, I would have thought there would be alot more rain associated with it.
I guess thats a good thing for Haiti.

Well that's not exactly a world class radar.

[Sean in New Orleans]

Louisiana is in full preparation mode, as well:

http://www.wafb.com/Global/story.asp?S=8903373

[gboudx]

Update from jeff:

Dangerous hurricane forecasted into the central Gulf of Mexico this weekend.

NOTE: NHC forecast is speeding up Gustav in the Gulf of Mexico with Sunday PM position now into the central Gulf.

Current:

Gustav is inland over SW Haiti and still moving toward the NW. IR and visible satellite images continue to show a well defined tropical cyclone...although very tiny. In fact hurricane force winds only extend outward 25 miles form the center...as this small inner core is over land.

Track:

The track reasoning remains fairly unchanged from earlier today with Gustav turning toward the W or WNW in the next 12 hours as strong high pressure builds over FL and the SE US. This high will guide Gustav toward or S of Cuba for the next 48 hours then gradually weaken as a new high takes shape over the central US into the MS Valley...this will be the final controlling factor and the end game of Gustav...and the target zone for US impact. For now it is too early to speculate on a region of risk as the 72+ hour forecast models are at great odds in the handling of the high over the southern US this weekend. One model is as far south as Tampico, MX with others at TX and LA. NHC continues to split the consensus and follow the guidance cluster through the center...a smart attempt at some sort of reasoning when the models are having difficulty.

With the holiday weekend upon us...I know people want concrete answers right now...but the uncertainty is just too great to attempt any final landfall location this far out. 5 day errors can be upwards of 300 miles and we are still 5-6 days away from a possible landfall. This is the best information at this time and time is on our side with this one.

My advice is to very closely monitor news sources through the next several days...persons leaving town should especially pay close attention.

Intensity:

With Gustav inland over Haiti's high mountains...it will likely weaken some over the next 6-12 hours. Once back over the water however there appears to be little to prevent rapid intensification. The trusted intensity models continue to forecast a major hurricane with winds of 125mph or greater as Gustav moves into the Gulf of Mexico. Given the warm loop current, little to no shear, and favorable outflow aloft I see no reason...especially given a tiny inner core as to why Gustav could not become a very dangerous cat 4/5 over the SE and C Gulf of Mexico. NHC brings the hurricane to 120mph and clearly states that their intensity may be conservative and as a reminder there is little to no skill at forecasting intensity changes beyond about 24 hours in a favorable environment. Once Gustav develops into a quasi-steady hurricane inner core dynamics and eyewall replacement cycles will dictate intensity through the final landfall.

Actions:

There is plenty of time for preparation...if and when the time comes.

The state of TX will be activating its Hurricane Response Plan for the potential impact of a major hurricane early next week this Thursday...this may move up some if the track timing changes.

Critical decisions will respect to mass evacuations and potential contra-flow will come around the H-40 to H-36 hours or around Friday and Saturday.

Residents along the TX coast should review there hurricane preparation supplies and make sure their hurricane kits are fully stocked...if you do not have one after Dolly and Edouard...now would be a great time to put one together.

Residents in coastal storm surge evacuation zones need to review their evacuation plans and be prepared to evacuate if the time comes.

Everyone should maintain at least 50% to 75% fuel supply in their vehicles through this week.

[KWT]

Current strength is hard to say, I suppose it could be set at 65kts given it will probably have gained a little strength by the time we have the next advisory.

O Town, a big majority of deep convection is offshore to the south of Haiti with the convection over the center pretty weak, as you'd expect given its just crossed land and been interacting with Haiti for the last 9hrs or so, the key thing to note is the inner core still looks good with a still closed eyewall, given those factors this should strengthen soon enough again.

As Jeff states, no reason why this won't be a powerful cat-4/5...