ATL: NATE - Post Tropical - Discussion

[CrazyC83]

It is always tough when you have such a difficult forecast. Especially one that is constantly changing, one that is very sensitive to small changes and the models don't agree on anything...

[dhweather]

While you cannot rule out rapid intensification, I am not confident that we will see that. There is a land interaction in the next 24 hours, which will disrupt the core. Once Nate departs the Yucatan and enters the Gulf, landfall on the Northern Gulf Coast is in 36 hours - a significant increase in forward speed. Typically, storms that undergo RI are not moving forward that rapidly. Lets see what we have when Nate enters the Gulf.

[Javlin]

LMAO at HMON with the small storm in the 930's coming in farther west still (Atchafalaya or Vermilion Bays).

https://www.tropicaltidbits.com/analysi ... 0&ypos=293

Saw that wiper effect.

[bella_may]

I've seen a few mets say the models could be underperforming on intensity

[chaser1]

From Levi (Tropical Tidbits) yesterday, Levi discussed the differences in the GFS and Euro 12z runs. He stated we could know this AM which was more accurate. His comments were the GFS and it models run off the GFS showed a stronger signature to the feature in the straits compared to the Euro. Additionally the Euro would be somewhat verifiable by this AM if there was a northward moving area of heavier precipitation/signature in the northern end of the trof axis offshore the East coast of Florida. Both seem to have come to fruition. The feature south of Key West is still sheared and an OPEN wave ...it was modeled to be closed off. Additionally, the enhanced rain is off the east coast, he continued, this would help promote height drops which could eventually help weaken the ridge to some degree. That was the notable differences in the 2 runs. I know the Euro swung well west in its last run, but does anyone think since it appears it was on to something from its 12z yesterday that it may bring that baroclinic pressure falls idea back into play in future runs?

His discussion was very good, and it looks like a piece of energy has broken off and headed east of Florida like he said yesterday's Euro was showing. Interesting to see if this affects the ridge like he said.


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Good point! At this point I'd think that you could be right but I'd think that the potential slight lowering in heights over Florida and E. Gulf might simply imply a bit more of a due north motion once Nate enters the Gulf. Perhaps even a bit quicker NNE turn while in the E. Central Gulf?? The net effect could of course mean a landfall closer to Apalachicola I suppose but i'm not sure if those subtle changes in the mid level heights would do enough in the short term to impact the more hostile conditions that Nate is/will encounter, contrary to had the storm remained offshore and in the Southwestern Caribbean for a day or two longer. I'd guess that any bit of longer exposure that Nate could get to that high oceanic heat content there in the NW Carib. would imply more strengthening and eventual threat to the N. Gulf coast, but I'm not too keen that any subtle pressure falls to the storms north over the next 12-24 hours will be adequate enough to change its land interaction or moving a bit quicker into the existing upper level shear just to its north.

[Steve]

European is initialized. We're now within 72 hours and though there is no general consensus except an LA/MS landfall, models diverge about 200 miles. Within 3 days usually means we will have some type of harmonic convergence between the majority of the models. This is a little different because while Nate has formed, it's got 1, 2 or 3 land interactions and then interaction with the noname system complicating the situation and also because Nate is going to come north in the Gulf pretty rapidly rather than taking its time as they often do when moving North in the Gulf. IDK. I decided I'm going to go to Austin tonight and just play things by ear. If it looks like we're going to get hit by a hurricane late Saturday night, I'll probably just drive home to deal with it. If it looks to go east, I'll just stay in Texas.

[CrazyC83]

While you cannot rule out rapid intensification, I am not confident that we will see that. There is a land interaction in the next 24 hours, which will disrupt the core. Once Nate departs the Yucatan and enters the Gulf, landfall on the Northern Gulf Coast is in 36 hours - a significant increase in forward speed. Typically, storms that undergo RI are not moving forward that rapidly. Lets see what we have when Nate enters the Gulf.

If it misses the Yucatan wide right, then I agree that RI is in play, but I can't see it with a disrupted core after leaving the Yucatan - it will take that much time just to reorganize itself, over cooler waters and in a higher shear environment.

[CrazyC83]

So far it appears a bit to the east and faster.

[Aric Dunn]

Euro keeping no name system little more south and more defined on the 12z run. being sling shotted northward rapidly.. much more realistic interaction with the noname system.

[Javlin]

Water temps yesterdayhttps://marine.rutgers.edu/cool/sat_data/show/?file=../../regions/gulfmexico/sst_comp/noaa/2017/img/171004.277.comp.lnt.jpg

[stormlover2013]

Gfs has done a pretty good job with this system, been the most consistent, Sw la to New Orleans is what I am thinking right now.

[CrazyC83]

12Z ECMWF: Sheared mess landfalls near NOLA.

[LarryWx]

Euro Hits SE LA at hour 72.

[crimi481]

Sure looks like no name absorbing Nate's bands and energy. Looks like a hybrid mess for e. gulf
http://www.goes.noaa.gov/HURRLOOPS/huwvloop.html

[Ken711]

 https://twitter.com/BigJoeBastardi/status/915998058533539840

[bella_may]

I don't know where the models are getting all this shear. The shear forecast is low as many mets have pointed out

[CrazyC83]

One thing we can probably say is that most of the impact will be east of the center, and it could spread out a fair distance.

[Aric Dunn]

Sure looks like no name absorbing Nate's bands and energy. Looks like a hybrid mess for e. gulf
http://www.goes.noaa.gov/HURRLOOPS/huwvloop.html

the two systems are definately attached at the hip ....

[CrazyC83]

I don't know where the models are getting all this shear. The shear forecast is low as many mets have pointed out

I think the shear is off the no-name trough that isn't being diagnosed very well. The faster movement keeps it in the influence of it.

[LarryWx]

Sure looks like no name absorbing Nate's bands and energy. Looks like a hybrid mess for e. gulf
http://www.goes.noaa.gov/HURRLOOPS/huwvloop.html

I think that this competition with noname is what will likely prevent RI but we'll see.