Tropical Storm Isaac, Part 2: Isaac Moving Into The Gulf Of Mexico-Hurricane Warnings For Morgan City, LA/MS/AL & FL Panhandle To Destin, FL

[Ian]

cool graphic.. first cone, most recent cone.. all tracks from nhc.

from: https://twitter.com/Geostrophic

[Ground Scouring]

I'm not going to agree or disagree with you with regards to the issued warnings...rather just point something out. The NHC produces a graphic of hurricane force wind speed probabilities. These probabilities max out around 10% on the Florida coast. By definition a hurricane warning is issued when hurricane conditions are expected. To me 10% is not expected...maybe 50 or 60%? Does anyone else see an inconsistency here? Again, I'm not saying the warnings should not be in place....just trying to understand if and why this inconsistency exists. Maybe I'm missing something....but I could see how this could be confusing to the public.

Given the latest intensity and satellite trends, however, would you say the chances are in effect higher than 10%, thereby necessitating the warnings?

[masswinter]

Given the latest intensity and satellite trends, however, would you say the chances are in effect higher than 10%, thereby necessitating the warnings?

I think you can make that argument. I have no problems with the warnings...more that there is an inconsistency between these two products. I think the hurricane wind speed probabilities are automated based off the official forecast. Just a case where automated products can sometimes not be too usseful. These days everyone wants to use probabilities...but if they don't match up with the forecast they can be counterproductive. I just think you need to be careful when generating atomated probabilites...because they might not always match what the forecaster thinks the actual probability is...which appears to be the case this time.

[WeSuck]

This situation is starting to become a bit alarming for a variety of reasons.

However, I think we need to see waht the next few model runs entail before really getting antsy. There is some cause for concern though and the last thing New Orleans needs is another pounding from a hurricane. I'm waiting to see what the model data holds the next few hours.

I agree, although any coastal city doesn't need a crawling bonified hurricane right over them. Lets see if EURO shifts west in a few hours following it's big east shift at 12z

[Superstorm93]

Not particularly new, but does illustrate the fact that this did re-establish a partial core once it moved off of Cuba.

[Derecho!]

Dr. Rick Knabb‏@NHCDirector2m

Not all tracks on model graphics are created equal. Some experimental, others simplistic and/or not even really forecast models.

Posted on Twitter at 12:08AM Today EDT

Though the problem of the general public looking at the exact forecast track instead of the cone is a problem, yet another problem cutting the other way are UNLABLED "spaghetti plot" sites that simply have a bunch of tracks, all the same color and width (including all the GFS ensembles) that are floating around getting linked to on "general public" sites that essentially equate the GFS, LBAR, CLIPER, and even XTRP, and which I've seen lead to comments like "the models are all over the place they don't know where it's going."

[Derecho!]

0Z UKMET is basically similar to 18Z

[NCSNOW]

144 hr GFS precip map dumps 8-15 inch's over a good chunk of LA. Trying to figure out what the exact storm surge would be on this run at that agle.

[lakeeffectkid383]

144 hr GFS precip map dumps 8-15 inch's over a good chunk of LA. Trying to figure out what the exact storm surge would be on this run at that agle.

This is NOT srge but this still cant be good.

http://www.weatherbellmodels.com/weather/wave/2012082518/wna/wave_height_dir_wna_23.png

[cmichweather]

Is anyone concerned that based on IR that this is still moving NW instead of the due west the models have? It does seem like the turn has started but, I think this is going to be close to landfall on the southern FL border.

[Superstorm93]

Is anyone concerned that based on IR that this is still moving NW instead of the due west the models have? It does seem like the turn has started but, I think this is going to be close to landfall on the southern FL border.

Actual center doesn't appear to be directly under the convection, but on the southern fringe.

Recon will confirm or deny and provide an accurate heading.

[Derecho!]

Is anyone concerned that based on IR that this is still moving NW instead of the due west the models have? It does seem like the turn has started but, I think this is going to be close to landfall on the southern FL border.

I don't think there is a single model that was showing a due west movement right for right now.

[Ground Scouring]

Is anyone concerned that based on IR that this is still moving NW instead of the due west the models have? It does seem like the turn has started but, I think this is going to be close to landfall on the southern FL border.

The heading over the past several hours appears slightly to the right of the NHC track, but not significantly so. Given the 00Z dynamical models’ good initialization, in the GFS suites at least, of the upper-air pattern, I think the system will turn shortly back on track in just under a few hours.

[EasternUSWX]

That is one strange looking storm. Looks like according to the models it should get better looking by tomorrow evening, as far a symmetry goes.

[phil882]

Is anyone concerned that based on IR that this is still moving NW instead of the due west the models have? It does seem like the turn has started but, I think this is going to be close to landfall on the southern FL border.

It looks like the storm is still on a wnw heading per radar.

Central core still working on getting organized...

[Dsnowx53]

The GFS ensemble mean continues the westward shift and targets New Orleans. It also really stalls the system as well. I'm curious to see the individuals later, as I'm sure a few members might even be well west of New Orleans.

[Superstorm93]

00z HWRF is west of it's 12z run

[turtlehurricane]

It looks like the storm is still on a wnw heading per radar.

Central core still working on getting organized...

Cool loop, fun to watch the vortex evolve as it begins to interact with the mountains of central Cuba. Recon will be interesting, maybe some sort of relocation.

[WEATHER53]

Is anyone concerned that based on IR that this is still moving NW instead of the due west the models have? It does seem like the turn has started but, I think this is going to be close to landfall on the southern FL border.

Sometimes they almost shy away from the land, the core would try to drift more north than west this case

[SN_Lover]

To add to the GFS outcome is the storm surge that would bring. at the angle it is coming from water would inundate lake pontchartrain for several hours, more so than Hurricane Katrina if the 0Z GFS verifies.

[Thunder Road]

Can we agree to refrain from Katrina comparisons until/unless a repeat is imminent?

[HurricaneJosh]

Can we agree to refrain from Katrina comparisons until/unless a repeat is imminent?

I agree that we need to view this with some skepticism. It's still more than 72 hr away and the models have been shifting quite a bit. I can't help but think there will be more windshield wiping.

[mempho]

Can we agree to refrain from Katrina comparisons until/unless a repeat is imminent?

Impossible to avoid really. Just watch the news tomorrow. Its pretty much perfect for comparing... and would be exactly 7 years to the day... and c'mon, you never name a hurricane Isaac. Too many coincidences there.

Sent from my Milestone X 2

[tornadotony]

Can we agree to refrain from Katrina comparisons until/unless a repeat is imminent?

There's no need to dramatically refrain from Katrina comparisons due to any sort of sensitivities if those comparisons have meteorological value. In this case, it is quite fair to say that a verbatim verification of the GFS would likely be more devastating for New Orleans than even a repeat of a Katrina scenario, given 1) the strengthen of the storm relative to its position to NOLA, 2) NOLA being in the right-front quadrant for an extended period of time, 3) the trajectory of the right-front quadrant winds relative to the orientations of the Mississippi River and Lake Ponchartrain, 4) the massive residence time the RFQ would have over New Orleans, and 5) the massive rainfall that would be occurring over NOLA on top of the wave and surge issues. It would be a disaster quite likely worse than Katrina because wind and freshwater flooding impacts would compound the wave and surge impacts worse than they did in Katrina. The levees may be stronger now, but they'll do no good if the surge goes over them. Of course, it's just one model run at a decently long range out still, but given that the discussion was specifically targeted to the model run, there's nothing wrong with what the poster said.

[deltadog03]

Is anyone concerned that based on IR that this is still moving NW instead of the due west the models have? It does seem like the turn has started but, I think this is going to be close to landfall on the southern FL border.

Agreed! This thing would have to start going due west pretty soon for the models to verify in the short term...

[Thunder Road]

Since it looks like I struck a point of contention, I'm going to voluntarily continue the Katrina debate in the banter thread.

[Big Jims Videos]

Please put this in the banter thread. It was created for that kind of talk. I've been enjoying the degreed mets analysis up to this point

[Scott747]

Since it looks like I struck a point of contention, I'm going to voluntarily continue the Katrina debate in the banter thread.

Where it should go for now. I understand the point made by Tony but history has shown us that the discussion quickly unravels into nothing but doomsday talk.

[Superstorm93]

Agreed! This thing would have to start going due west pretty soon for the models to verify in the short term...

That's a negative.

Center is very close to Cuba still.

2:00 AM EDT Sun Aug 26

Location: 22.9°N 78.0°W

Moving: NW at 17 mph

Min pressure: 997 mb

Max sustained: 60 mph

[tornadotony]

I agree that we need to view this with some skepticism. It's still more than 72 hr away and the models have been shifting quite a bit. I can't help but think there will be more windshield wiping.

I wouldn't say windshield wipering. To be honest, the westward shift has strong meteorological basis given the likely building back of the ridge. Minor changes are still likely, but to be honest, I think landfall is probably going to fall in a zone from Houma, LA, to Mobile, AL. And the fact of the matter is, whether we like it or not, NOLA is in that region, and it takes a full 72 hours to properly execute an evacuation. We are about 72 hours out already. If a proper evacuation of NOLA is to occur, it has to start tomorrow, whether we as meteorologists are certain about impacts to the city or not. It's just the way it is unless we want to risk having what happened with Katrina happen again.