ATL GUSTAV: Tropical Depression - Discussion

[6SpeedTA95]

Pressure seems pretty steady, but the winds are even lower than before. Recon data on first pass doesn't even support cat 2 winds.

It's a complete wreck of a storm right now, the north and northwest quads are inundated with dry air and shear is hampering outflow.

[HenkL]

At 1108Z NOAA3 reported extrapolated SLP 953, so this time it actually is 2 mb up.

[6SpeedTA95]

Pressure seems pretty steady, but the winds are even lower than before. Recon data on first pass doesn't even support cat 2 winds.

That is interesting. Is it normal for a storms winds to go down slightly as it begins restrengthening? Although this doesn't sound slight to go down to a category 1. Just weird since the mb dropped 5 points.

Changes in windspeed can in many cases lag behind a change in pressure.

[jasons2k]

Well this goes to show how little skill we have in intensity forecast. I went to bed thinking it was quickly reorganizing and I thought for sure we'd have a Cat. 5 (or close to it) on our hands when I woke-up.

[tolakram]

Outflow appears to be expanding on the south side, probably because southerly shear si lessening as Derek pointed out. Also note that the center (eye) is slowly becoming more apparent.

[Derek Ortt]

The lowest pressure from the NOAA plane in the recent pass is 955.5 mbs.

So going down slightly? Just woke up so not sure how that compares to the last runs.

Down 5 mbs from the last pass.

no... they were extrapolating 950 earlier... they have been running 5-10mb too low for both flights

[6SpeedTA95]

Outflow appears to be expanding on the south side, probably because southerly shear si lessening as Derek pointed out. Also note that the center (eye) is slowly becoming more apparent.

All this happened about 8 or 9 hours ago. Until we see sustained signs of increased outflow and an organized eye I'll just chalk it up to a cycle in the storm.

[superfly]

Pressure seems pretty steady, but the winds are even lower than before. Recon data on first pass doesn't even support cat 2 winds.

That is interesting. Is it normal for a storms winds to go down slightly as it begins restrengthening? Although this doesn't sound slight to go down to a category 1. Just weird since the mb dropped 5 points.

It's not strengthening right now, it's just trying to keep itself together. The next 6-10 hours will be crucial as it will be passing over the loop current. After that, the heat potential drops off significantly and it will not have as much of a chance to re-strengthen into a significant storm.

[HarlequinBoy]

A few people are sort of downplaying a Category 3 storm.

Ivan and Wilma were Cat 3, and even Katrina, although it did have a Cat 5 storm surge.

Well if I at anypoint came off as trying to downplay it I apologize. Simply meant to state compared with what the models were showing yesterday this was welcome news.

Although now the cp has dropped a bit

Oh no, it's okay. No problem. And yeah I guess you're right about that.

[Sanibel]

If Gus is dropping 5 millibar amounts at a pass it could be translating the GOM SST hot spot into intensity now. Last time Gus dropped blocks of pressure he went to 150mph. The healthy upper appearance could aid it in reforming if these drops continue. But with surface weakness recorded it could only translate into a return to upper category 3.

[BigB0882]

Is the majority, or all, of the shear coming from the south? If that is lessening, does that mean that the south side will gets it act together followed by the north and northwest sides as the dry air is worked out? I just don't want to get too excited about a weaking storm and I don't want people to let their guards down. This thing has another few hours, IMO, to strengthen before it gets past those really warm waters.

[6SpeedTA95]

no... they were extrapolating 950 earlier... they have been running 5-10mb too low for both flights

Theyr'e showing 960 on the NHC update?


On a seperate note my buddy that works at noaa needs to wake his ass up!

[PTrackerLA]

Well I am up, it's time to rush all preparations to completion. I'm extremely nervous but we are going to hunker down the best that we can. It's a very calm and peaceful morning here, you would never know. I won't have much time to post today but will be checking periodically. Good luck everyone else.

[HarlequinBoy]

The southern outflow does at least seem a bit better.

[tallywx]

I can't believe how difficult it is to "please" people around here anymore - that a cat 3 that's 30 hours from landfall isn't generating much buzz. I think all the category 5 hurricanes of the past few years have really "spoiled" all of you. I remember back in the mid 90s right when we were coming out of the hurricane lull - cat 3 hurricanes were treated with the attention and respect that they deserve. Now, like everything else in the world, it either has to break records or its not worth paying attention to. I think we're selling ourselves short with that mindset.

Now I understand why people were jumping on me like crazy late last night when I suggested this thing was weakening. People didn't want to accept that might "only" be a hurricane that causes "extensive" damage at landfall instead of catastrophic. Well reality is reality, and you all are just going to have to be rightly excited by what is still a powerful storm.

[HURAKAN]

[Recurve]

Well I am up, it's time to rush all preparations to completion. I'm extremely nervous but we are going to hunker down the best that we can. It's a very calm and peaceful morning here, you would never know. I won't have much time to post today but will be checking periodically. Good luck everyone else.

GOOD LUCK. Can you tell us anything about the evac there? I have a friend heading from NOLA to Baton Rouge, taking the "back way" (airline to I310 to west bank and up the inside of the river).

[Weatherfreak000]

The stronger Gustav gets, the more dangerous this landfall is gonna be im worried. The storm is moving way too fast to significantly weaken like Katrina, and it seems to have a somewhat tight inner core.


If this thing gets back up to Category 4 it will probably make landfall that way...it's a very scary scenario. Theoretically, if it could make Cat 5 I would assume it's moving fast enough to perhaps affect the extreme SELA coast with those conditions before weakening into a Cat 4. Scary stuff.

[tallywx]

The stronger Gustav gets, the more dangerous this landfall is gonna be im worried. The storm is moving way too fast to significantly weaken like Katrina, and it seems to have a somewhat tight inner core.


If this thing gets back up to Category 4 it will probably make landfall that way...it's a very scary scenario. Theoretically, if it could make Cat 5 I would assume it's moving fast enough to perhaps affect the extreme SELA coast with those conditions before weakening into a Cat 4. Scary stuff.

If anything the inner core is unraveling before our very eyes. The "eye" now consists of a partial eyewall and a large dry slot wrapping into its eastern side. That's not to say that the storm can't spread out and go steady-state on us like Wilma if shear relaxes just a bit, which would actually increase the threat on New Orleans due to aerial coverage of the strong winds piling up water.

[cheezyWXguy]

Well pretty much all I can see that is preventing this from undergoing a second episode of RI is the lack of convection on the eastern side. The eye is clearing out now, and outflow is compacting a little, suggesting that the outer windfield is weakening, allowing the inner one to strengthen, as I was saying last night, giving this that buzzsaw look. Once convection wraps around the eye, RI=good to go (just like taco bell's crunch wraps mmm)