ATL: DELTA - Post-Tropical - Discussion

[USTropics]

Major Hurricane Delta now forecasted to go right over my house Friday evening. Realistically, what wind speeds would I receive in Lafayette if Delta makes landfall at 125mph?

Based on a blend of the ECMWF/GFS/UKMET/ICON realistically I would prepare for sustained winds in excess of at least 80 mph. Here is a forecast of gusts by mentioned models (current forecasts Lafayette could experience gusts exceeding 90-100 mph):

ECMWF


GFS


UKMET


ICON

[Hurricane Mike]

New video update on Delta
https://www.youtube.com/watch?v=XJA090vJXl4

[eastcoastFL]

Is Delta pulling the remnants of gamma into its inflow?

[USTropics]

18Z NAM @ 60 hours

Has any storm ever been below 900 mb?

https://i.imgur.com/Vf05V5E.png

Hurricane Gilbert in 1988 recorded a pressure of 888mb.

Didn't Wilma peak at 882 mg before it weakened some?

That's correct. From ibtracs:

Code: Select all

SEASON   NUMBER   NAME   DATE   STATUS   STATUS   STATUS   LAT   LON   WIND   PRES   SPD   DIR   ACE   
2005   97   WILMA   10/19/2005 6:00   AL252005   HU   TS   17   -82.2   150   892   6   311   2.25   

And that was the wrong grab, here is the actual reading for 882mb for Wilma:

Code: Select all

2005   97   WILMA   10/19/2005 12:00   AL252005   HU   TS   17.3   -82.8   160   882   6   285   2.56   

[USTropics]

Is Delta pulling the remnants of gamma into its inflow?

Yes, that process started about ~12 hours ago. Here are the last few analysis images from the GFS + 24 hour forecast showing this evolution:

[Emmett_Brown]

New recon flight just took off from Lakeland

[ColdMiser123]

The 18z GFS averaged shear just before landfall is actually lower than what it was during Laura. The main difference is the cooler water just offshore which should induce some weakening.

[jlauderdal]

Sorry I didn't mean to stir up any trouble with the models, I just thought it was interesting to see it predict such a low MB.

Trouble and models are synonymous on this board, no apology needed

[Steve]

18Z NAM @ 60 hours

Has any storm ever been below 900 mb?

https://i.imgur.com/Vf05V5E.png

Yes, many storms have been under 900mb. But please never use the NAM for tropical cyclones, it overestimates intensity bigtime.

Of course it does, and we lauded it for entertainment in the models thread. But you certainly can and should use it when it drops valuable information. Clearly the 899 is a joke. But what it says (and it was good in the low-mid 20's latitudes once with Harvey) is that it expects reintensification after emergence off the Yucatan. Yeah, you have to pick and choose and glean what you get out of it. But the NHC also does have it returning to a 4 near where that 899mb plot is at 60 hours. Maybe it gets that right - just not the actual pressure.

[aspen]

New recon flight just took off from Lakeland

Finally, we’ll know what on Earth is going on in that blob of pink and white. I’m guessing they’ll find a slightly weaker system, maybe 105-110 kt and 955-960 mbar.

[cheezyWXguy]

That cdo lookin real weird right now

[USTropics]

18Z NAM @ 60 hours

Has any storm ever been below 900 mb?

https://i.imgur.com/Vf05V5E.png

Yes, many storms have been under 900mb. But please never use the NAM for tropical cyclones, it overestimates intensity bigtime.

Of course it does, and we lauded it for entertainment in the models thread. But you certainly can and should use it when it drops valuable information. Clearly the 899 is a joke. But what it says (and it was good in the low-mid 20's latitudes once with Harvey) is that it expects reintensification after emergence off the Yucatan. Yeah, you have to pick and choose and glean what you get out of it. But the NHC also does have it returning to a 4 near where that 899mb plot is at 60 hours. Maybe it gets that right - just not the actual pressure.

Absolutely, I wouldn't read too much into the sub 900mb pressure reading, but rather the agreement it has with the intensity models on a secondary peak in the GOM. The HWRF (posted in the models thread) has a secondary peak of 929mb. Here a reference to that:

[FLpanhandle91]

Cloud tops in the southern eyewall right now are some of the coldest I have ever seen in the Atlantic Basin.

[sikkar]

Is it moving straight west or it's an optical illusion?

[GCANE]

Big time lightning firing back up in the core.

[toad strangler]

 https://twitter.com/pppapin/status/1313602788908204035

[GCANE]

If there was an EWRC, it may be over.

[GCANE]

Unprecedented. Off-scale on IR.
Obviously punching thru the tropopause into the stratosphere.
Add another check to HWRF accuracy.

[Keldeo1997]

https://prntscr.com/uudhu7

https://prntscr.com/uudhxg

The shear probably won't last. GFS has it dropping down to 11kts at 00Z and 5kts at 06Z

[kevin]

At what time is recon expected to arrive? What do you expect they'll find? Delta has been struggling a bit (relatively speaking) since the last recon, but it's starting to look more impressive again lately.