ATL: NATE - Post Tropical - Discussion

[Alyono]

compared the GFS IR to reality... not even close

[bamajammer4eva]

Local forecasters must be going with Euro. We had the tropical storm conditions possible in our forecast for Sunday this morning. It changed this afternoon to Windy with Rain. Now for the Friday AM forecast for Sunday, it is back to Tropial Storm Conditions Possible with also Rain May be Heavy at times. Forecast changing with each model run!

[Steve]

NAM 06z wants to show strengthening. Small storm and it was 30mb or so off on Harvey coming up from the S but 12km goes to the 970s and 3km so far 920s. That's not going to happen. Worst weather is indicated from Plaquemines Parish over to S AL.

12km run
https://www.tropicaltidbits.com/analysi ... 77&ypos=48

3km
https://www.tropicaltidbits.com/analysi ... 112&ypos=0

[Hammy]

The GFS/CMC don't strengthen it at all from this point on even though out over hot water while the Euro and UK do. Will the GFS/CMC score a coup or will they look stupid? We should know something within the next 6-9 hours. The current firing up is making me suspect they will look stupid.

the new EC shoots the channel, yet doesn't intensify it

I wonder if the models are having issues resolving Nate from the monsoon trough?

Could the low in the Gulf be interfering with the model solutions?

[Alyono]

The GFS/CMC don't strengthen it at all from this point on even though out over hot water while the Euro and UK do. Will the GFS/CMC score a coup or will they look stupid? We should know something within the next 6-9 hours. The current firing up is making me suspect they will look stupid.

the new EC shoots the channel, yet doesn't intensify it

I wonder if the models are having issues resolving Nate from the monsoon trough?

Could the low in the Gulf be interfering with the model solutions?

no doubt. The upper low destroyed the surface trough, so the models are already wrong. The Gulf low was never closed, yet the models said it was

[WeatherGuesser]

A Storm Surge Watch is in effect for...
* Morgan City Louisiana to the Alabama/Florida border
* Northern and western shores of Lake Pontchartrain

A Hurricane Watch is in effect for...
* Morgan City Louisiana to the Mississippi/Alabama border
* Metropolitan New Orleans
* Lake Pontchartrain and Lake Maurepas
* Punta Herrero to Rio Lagartos Mexico

A Tropical Storm Watch is in effect for...
* Mississippi/Alabama border to the Okaloosa/Walton County Line
* West of Morgan City to Intracoastal City Louisiana

[N2FSU]

UKMET plotted on my aviation software

:

[ronjon]

06z GFS shifted east more like the 00z UKMET. Now close to Ala-Miss border at landfall. Also stronger than 00z run. It also moves through the Yuc channel without any land interaction now similar to HWRF and other models.

https://www.tropicaltidbits.com/analysis/models/?model=gfs&region=seus&pkg=mslp_pcpn_frzn&runtime=2017100606&fh=54

[GCANE]

Heavy convection very close to the CoC.
Didn't waste anytime once he got over the water.
Visible Satellite will tell a lot about how this develops today.

[GCANE]

Last analysis from AMSU showed a solid warm core over land.

[N2FSU]

Seems like subtle eastward adjustment in the model trends overnight perhaps.

[GCANE]

Mid-level vort is a bit south of the low-level vort.
500mb vort is broad and not closed off on the SW quad due to the gyre.

ULL to the west appears to be slowly weakening and moving west.
Updraft from the heavy convection in the WPAC is creating an anti-cyclone to the south and southwest of Nate.
Shear from this combo appears to be limited to the west side of Nate.

Need some very heavy convection to get this all stacked up.
Tons of high CAPE air and TPW being sucked in.
Moving into very high Ocean Heat-Content water.

Could just happen - Stay tuned.

[GCANE]

GFS +12hr
Completed saturated air column, zero shear.

[GCANE]

Nate may latch onto that UL High, now to its NE, about the time he hits the southern flank of the Loop Current.

[NDG]

I can see why the models don't want to show much intensification while is over the western Caribbean, there is big push of southerly winds to the NE of Nate this morning, cutting off some of the southerly inflow into Nate, limiting its core of convection closest to the LLC only to its SW quadrant this morning.

[GCANE]

No impairments for the vort column to stack once in the GOM.
Actually has a moderate PV ring which aids outflow thru secondary circulation from updraft thru Nate to downdraft at the PV anomoly.

[NDG]

I guess the NOAA recon thought the LLC was further north than where it actually is.

[GCANE]

Latest radar from Kermit

[NDG]

So far the NOAA Recon is just finding a broad and weak coc.

[GCANE]

 https://twitter.com/NHC_Atlantic/status/916225643045621760