ATL: HARVEY - Post-Tropical - Discussion

[SunnyThoughts]

abc13.com reporting many people who are trying to evacuate considering all these mandatory evacuations, are finding some of the roads they were given as their evacuation route are flooded.

[WeatherGuesser]

Forecast is still fluctuating, but I've seen WFO PAH mention the possibility of 5" or so into parts of KY as the remnants move through in a few days. It's been very, very dry and a heavy downpour would likely run off instead of doing much good.

[stormreader]

Looking at the Slider you can definitely see where the LLC is

http://rammb-slider.cira.colostate.edu/ ... mmb-slider

Looks like there might be some shear though

Structure looks fine.

Matter of fact, it's hard not to believe that there won't be some strengthening. Looking very near the coast on that loop, very near those blooming storms at the coast, to see if a much tighter swirl begins to organize there. Wonder if we have another surprise left from Harvey--an unexpectedly strong storm at a second landfall. I'm not going to discount that. Well established circulation pressure about 997-998 entering GOM---think favors at least a strong trop storm at 2nd landfall (65-70 mph). Think I'm being conservative here. Don't think pressure would have to drop that much for those kind of winds, with such a well established cyclonic flow.

[Nimbus]

Looking at the Slider you can definitely see where the LLC is

http://rammb-slider.cira.colostate.edu/ ... mmb-slider

Looks like there might be some shear though

Structure looks fine.

Pressure gradient is pretty flat otherwise it would have exploded like it did coming off the Yucatan.
Glad to hear the possibility that the Houston area flooding might have crested for the moment.
NHC said the core was gone so maybe we won't see those heavier feeder bands setting up.

[Langinbang187]

That dry air is gonna give Harvey a lot of issues. Will most definitely keep him in check.

[Sanibel]

The surface feature looks like it has done well by the section that was over water already...Now it is visibly moving offshore...

[Aric Dunn]

Looks like that slot of dry air has moved over the center. Just have to see if its enough to keep it down.

[xironman]

That dry air is gonna give Harvey a lot of issues. Will most definitely keep him in check.

Generally agree, you can see from the radar that over land the daytime heating gives lapse rates that allow storms to blow through the dry air cap, but not so much over water. I guess we will need to wait to dmax to see if that changes there. Harvey does have an envelope of moist air clearly seen in the WV loops, so I am not counting him out yet.

[Blinhart]

From looking at radar and everything else it looks like the center is already booming and barely offshore, the more he moves offshore it looks like he could get his act together real fast and could make a run back to Major if he gets far enough off shore, since they are saying he has about 48 hours of being offshore.

[stormreader]

The surface feature looks like it has done well by the section that was over water already...Now it is visibly moving offshore...

Not even completely sure its llc is completely off the coast yet. Thought so earlier, but as others have said, not quite.

[Langinbang187]

From looking at radar and everything else it looks like the center is already booming and barely offshore, the more he moves offshore it looks like he could get his act together real fast and could make a run back to Major if he gets far enough off shore, since they are saying he has about 48 hours of being offshore.

[tolakram]

From looking at radar and everything else it looks like the center is already booming and barely offshore, the more he moves offshore it looks like he could get his act together real fast and could make a run back to Major if he gets far enough off shore, since they are saying he has about 48 hours of being offshore.

No model is showing anything even close to a major, mostly just maintaining tropical storm status.

[stormreader]

From looking at radar and everything else it looks like the center is already booming and barely offshore, the more he moves offshore it looks like he could get his act together real fast and could make a run back to Major if he gets far enough off shore, since they are saying he has about 48 hours of being offshore.

Well, I wouldn't use the term "major". But even with a pressure remaining of about 995 or so, a slight drop, with this circulation so well established, I think you could get 65-70 mph winds along the Tex-La border area.

[wxman22]

I can't believe that the rain is still coming down! i am very concerned about the bands possibly strengthening overnight, which some of the models hint at...

You and your fellow Texans are all in our prayers wxmann, you take care of yourself and be safe!

Aww, thank you! it really means alot!

[txwatcher91]

Within the next 30 hours the 18z 3km NAM, which has done fairly well with the banding of Harvey, drops an additional 15-22" of rain across the Houston area.

[xironman]

Looks like that slot of dry air has moved over the center. Just have to see if its enough to keep it down.

Into it or around it. Back in the day S2K, had a met by the name of Derick who clarified that dry air was most effective at killing a cyclone if there was enough mid-level shear to push it into the circulation itself. Not sure that is the case here, but do agree the surrounding dry air is probably a limiting factor.

[SunnyThoughts]

Seeing some mets discussing the 3k nam model. Hopefully it isn't right, just dumps more water over Houston area for like 3 more days.

[stormreader]

Looks like that slot of dry air has moved over the center. Just have to see if its enough to keep it down.

Into it or around it. Back in the day S2K, had a met by the name of Derick who clarified that dry air was most effective at killing a cyclone if there was enough mid-level shear to push it into the circulation itself. Not sure that is the case here, but do agree the surrounding dry air is probably a limiting factor.

I think the wind obs noted in SE Texas are important. Stronger now than ever. I would also begin to look at reported obs in SW La. As the storm comes off the coast, it might almost have a sub-tropical look. Expect a decent size circulation. That might actually be good for less rainfall, if its the case. Just speculating. But you could have a pretty windy storm in that event---995 or so mb with winds 65-70mph. In that scenario, you wouldn't have as much of a CDO. Just one scenario, just speculating. But I do expect some intensification, regardless.

[WeatherGuesser]

I see the possible CoC just offshore of the outer banks of Calhoun county, but I also see a large feeder moving due north into Lake Charles, LA.

[stephen23]

Appears Harvey is pulling moisture from the low over Chicago