ATL: NATE - Post Tropical - Discussion

[Chris_in_Tampa]

Air Force vortex message was extrapolated.


URNT12 KNHC 071137
VORTEX DATA MESSAGE AL162017
A. 07/11:10:20Z
B. 25 deg 21 min N
087 deg 51 min W
C. 700 mb 2986 m
D. 32 kt
E. 253 deg 7 nm
F. 357 deg 27 kt
G. 252 deg 8 nm
H. EXTRAP 988 mb
I. 12 C / 3050 m
J. 15 C / 3047 m
K. 8 C / NA
L. NA
M. NA
N. 1234 / 7
O. 0.02 / 2 nm
P. AF305 0816A NATE OB 04
MAX OUTBOUND AND MAX FL WIND 88 KT 049 / 47 NM 11:24:10Z
SLP EXTRAP FROM 700 MB
MAX FL TEMP 15 C 239 / 9 NM FROM FL CNTR

[tolakram]

NHC

[SunnyThoughts]

85 mph. 986 mb

[tolakram]

NHC landfall forecast

[wxman57]

Here is NOAA’s latest storm surge forecast. When this map opens it is zoomed in a bit on the Mobile Alabama area. Red indicates a storm surge of more than 9 feet.

If you zoom in any more then the surge forecast data does not appear. The zoom levels at which this data appears on the map is defined on NOAA’s GIS server. I have no control over that setting.

To see the map legend please click “Map Tips” in the upper left corner.

Map link: https://goo.gl/vYPTKg

Remember, that's not a forecast, it is a reasonable worst-case. In addition, it does not predict surge height, it indicates potential water depth (inundation). The surge would be higher unless locations in red are right at sea level.

[tolakram]

SLIDER IR
http://rammb-slider.cira.colostate.edu/?sat=goes-16&sec=conus&x=5501&y=5588&z=3&im=18&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=0&p%5B0%5D=13&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&s=rammb-slider

[GCANE]

[stormreader]

Track errors

Well, I don't know what to say. This chart shows the recent strong performance of the Euro in regard to smaller track errors. We see the current Euro landfall forecast is Grand Isle, La with a move N toward New Orleans, while most of the other models with larger errors in their forecasts take the storm toward the Pascagoula Miss area. NHC is giving greater weight, I guess, to the abundance of models taking the storm further east, while the strongest model insists on a more westerly solution.

[Jelff]

Remember, that's not a forecast, it is a reasonable worst-case. In addition, it does not predict surge height, it indicates potential water depth (inundation). The surge would be higher unless locations in red are right at sea level.

Thanks for correction.

[stormreader]

85 mph. 986 mb

Almost assuredly will be at least a Cat 2 at landfall.

[tolakram]

Well, I don't know what to say. This chart shows the recent strong performance of the Euro in regard to smaller track errors. We see the current Euro landfall forecast is Grand Isle, La with a move N toward New Orleans, while most of the other models with larger errors in their forecasts take the storm toward the Pascagoula Miss area. NHC is giving greater weight, I guess, to the abundance of models taking the storm further east, while the strongest model insists on a more westerly solution.

All that matters at this point is the 24H and less performance, where the GFS and other models have done a little better. We saw this with Irma as well. Euro has always had a left bias so I would go somewhere east of Euro and a little west of GFS.

[tolakram]

Looking at the bias chart, it may go east of most of the models.

[wxman57]

85 mph. 986 mb

Almost assuredly will be at least a Cat 2 at landfall.

I'm not seeing that at all. Plane is finding Nate to be less organized than less evening. FL winds are lower, SFMR readings lower. And what's with the virtually no wind west of the center? That's very odd.

[tolakram]

200 frame COD IR loop

http://weather.cod.edu/satrad/exper/?parms=meso2-13-200-1-100

[Chris_in_Tampa]

Air Force at 700mb level. Through 6:48am CDT.
NOAA at 750mb level. Through 6:54am CDT.

Level difference might account for difference in vortex locations.

About the last images from me. I might do one once NOAA vortex message comes in.

[NDG]

Good news is that Nate has not strengthen much in the past 6 hrs or so. All global models remain to the west of the NHC track, and Nate better start heading almost due north to follow the NHC track this morning.

[NDG]

85 mph. 986 mb

Almost assuredly will be at least a Cat 2 at landfall.

I'm not seeing that at all. Plane is finding Nate to be less organized than less evening. FL winds are lower, SFMR readings lower. And what's with the virtually no wind west of the center? That's very odd.

AF recon found 88 knots flight level winds a few minutes ago, that's about as high as they were last night. Also the SFMR are higher.

[wxman57]

Good news is that Nate has not strengthen much in the past 6 hrs or so. All global models remain to the west of the NHC track, and Nate better start heading almost due north to follow the NHC track this morning.

What do you make of those recon reports west of the center? Very odd. Not even any tropical storm-force wind west of the center? Second plane is indicating a similar wind field.

[GCANE]

Looks like a line of towers is firing on the NE quad of the CoC creating a hot spot to their right instead of into the core.
Kermit's radar is picking it up.
It looks like they are trying to figure out where to go.

[otowntiger]

85 mph. 986 mb

Almost assuredly will be at least a Cat 2 at landfall.

I'm not seeing that at all. Plane is finding Nate to be less organized than less evening. FL winds are lower, SFMR readings lower. And what's with the virtually no wind west of the center? That's very odd.

Agreed- it looked like last night it was on the verge of RI- everyone one was getting all worked up about- that clearly did not materialize. And the lack of wind on the west side could have a lot to do with it's rapid forward motion cancelling out the northerly winds, maybe? I think it's moving so fast it's keeping itself in check.