September 2021: Hurricane Nicholas

General Weather Discussions and Analysis
davidiowx
Posts: 1063
Joined: Thu Jan 23, 2014 2:39 pm
Location: Richmond, TX
Contact:

javakah wrote: Sat Sep 11, 2021 8:40 pm I remember that for Harvey, the QPF guys had to add not one, but two new colors to their charts to indicate the potential for 30+ inches, with a note that those might not even be sufficient. The insane predicted rainfall amounts were what prompted me to get the hell out of Dodge for Harvey.
I remember that very well. I recall one QPF output with 43” over 5 days. Don’t quote me on that, but the consistency of “500 year flood” type situations (think 79, 89, 94, etc.) was surreal. It literally happened, and some.

I don’t think this will be anything like that, but we always need to pay attention, things can get ugly in 6-8 hours in the GoM during peak season.
User avatar
DoctorMu
Posts: 5691
Joined: Sun Jun 28, 2015 11:58 am
Location: College Station
Contact:

davidiowx wrote: Sat Sep 11, 2021 9:07 pm
javakah wrote: Sat Sep 11, 2021 8:40 pm I remember that for Harvey, the QPF guys had to add not one, but two new colors to their charts to indicate the potential for 30+ inches, with a note that those might not even be sufficient. The insane predicted rainfall amounts were what prompted me to get the hell out of Dodge for Harvey.
I remember that very well. I recall one QPF output with 43” over 5 days. Don’t quote me on that, but the consistency of “500 year flood” type situations (think 79, 89, 94, etc.) was surreal. It literally happened, and some.

I don’t think this will be anything like that, but we always need to pay attention, things can get ugly in 6-8 hours in the GoM during peak season.
Yeah, 2-3 feet was predicted before landfall. The level of rapid intensification into a CAT4 just at landfall at Rockport was IIRC a bit more remarkable. Intensification into CAT2-3 was expected and it was rapid from depression to CAT4.

Can never count out rapid intensification over GoM waters, especially with a Coast Hugger. 20-30 mile difference in the path of the center could be huge.
weatherguy425
Pro Met
Pro Met
Posts: 830
Joined: Wed Feb 03, 2010 7:45 pm
Location: Atlanta, Georgia
Contact:

DoctorMu wrote: Sat Sep 11, 2021 9:45 pm
davidiowx wrote: Sat Sep 11, 2021 9:07 pm
javakah wrote: Sat Sep 11, 2021 8:40 pm I remember that for Harvey, the QPF guys had to add not one, but two new colors to their charts to indicate the potential for 30+ inches, with a note that those might not even be sufficient. The insane predicted rainfall amounts were what prompted me to get the hell out of Dodge for Harvey.
I remember that very well. I recall one QPF output with 43” over 5 days. Don’t quote me on that, but the consistency of “500 year flood” type situations (think 79, 89, 94, etc.) was surreal. It literally happened, and some.

I don’t think this will be anything like that, but we always need to pay attention, things can get ugly in 6-8 hours in the GoM during peak season.
Yeah, 2-3 feet was predicted before landfall. The level of rapid intensification into a CAT4 at landfall at Rockport was iIRC a bit more remarkable. CAT2-3 was expected.

Can never count out rapid intensification over GoM waters, especially with a Coast Hugger. 20-30 mile difference in the path of the center could be huge.
Dry air and 15KT-20KT southwesterly shear should cap it pretty well as it approaches the coast. But, of course, not set in stone just yet.
bdog38
Posts: 56
Joined: Tue Jun 29, 2010 10:30 pm
Contact:

weatherguy425 wrote: Sat Sep 11, 2021 9:47 pm
DoctorMu wrote: Sat Sep 11, 2021 9:45 pm
davidiowx wrote: Sat Sep 11, 2021 9:07 pm

I remember that very well. I recall one QPF output with 43” over 5 days. Don’t quote me on that, but the consistency of “500 year flood” type situations (think 79, 89, 94, etc.) was surreal. It literally happened, and some.

I don’t think this will be anything like that, but we always need to pay attention, things can get ugly in 6-8 hours in the GoM during peak season.
Yeah, 2-3 feet was predicted before landfall. The level of rapid intensification into a CAT4 at landfall at Rockport was iIRC a bit more remarkable. CAT2-3 was expected.

Can never count out rapid intensification over GoM waters, especially with a Coast Hugger. 20-30 mile difference in the path of the center could be huge.
Dry air and 15KT-20KT southwesterly shear should cap it pretty well as it approaches the coast. But, of course, not set in stone just yet.
. its not about the forecast.. sometimes mother nature lets us know whos in charge. hurricanes? allison and harvey non hurricanes when
they arrived in houston. Ice anyone.........
skidog48
Andrew
Site Admin
Site Admin
Posts: 3440
Joined: Wed Feb 03, 2010 9:46 pm
Location: North-West Houston
Contact:

Well 00Z GFS is interesting so far. SHows 981mb storm east of Brownsville at 48H out.
For Your Infinite Source For All Things Weather Visit Our Facebook
Scott747
Posts: 1488
Joined: Tue Feb 23, 2010 9:56 am
Location: Freeport/Surfside Beach
Contact:

Andrew wrote: Sat Sep 11, 2021 11:14 pm Well 00Z GFS is interesting so far. SHows 981mb storm east of Brownsville at 48H out.
It was having some 5-7 mb swings in some of the increments. Smoothes out but some wild swings.

Looks like it's going to tease Freeport/Surfside and Galveston before moving towards the border.
Andrew
Site Admin
Site Admin
Posts: 3440
Joined: Wed Feb 03, 2010 9:46 pm
Location: North-West Houston
Contact:

Scott747 wrote: Sat Sep 11, 2021 11:20 pm
Andrew wrote: Sat Sep 11, 2021 11:14 pm Well 00Z GFS is interesting so far. SHows 981mb storm east of Brownsville at 48H out.
It was having some 5-7 mb swings in some of the increments. Smoothes out but some wild swings.

Looks like it's going to tease Freeport/Surfside and Galveston before moving towards the border.
Really weakens it as it approaches Western Louisiana. Amazing how consistent it has been for the last couple of days in showing a solution like this with little support from other models or much of the ensembles.
For Your Infinite Source For All Things Weather Visit Our Facebook
Stormlover2020
Posts: 457
Joined: Mon Jun 01, 2020 6:04 pm
Contact:

Will meet in the middle the models will
Stratton20
Posts: 4248
Joined: Tue Feb 09, 2021 11:35 pm
Location: College Station, Texas
Contact:

I think with this run, we can officially throw the GFS in the trash can for this system at least, 981mb is near cat 2 strength and I really just think the GFS is overdoing this system, even the 00z ICON is more in line with the Euro solution
Scott747
Posts: 1488
Joined: Tue Feb 23, 2010 9:56 am
Location: Freeport/Surfside Beach
Contact:

Andrew wrote: Sat Sep 11, 2021 11:23 pm
Scott747 wrote: Sat Sep 11, 2021 11:20 pm
Andrew wrote: Sat Sep 11, 2021 11:14 pm Well 00Z GFS is interesting so far. SHows 981mb storm east of Brownsville at 48H out.
It was having some 5-7 mb swings in some of the increments. Smoothes out but some wild swings.

Looks like it's going to tease Freeport/Surfside and Galveston before moving towards the border.
Really weakens it as it approaches Western Louisiana. Amazing how consistent it has been for the last couple of days in showing a solution like this with little support from other models or much of the ensembles.

Yeah it does seem to be locking in. A little faster in this run and also hits a wall around Cameron/Baton Rouge. Good thing it doesn't have much moisture to work with.

Unless the other globals change or the GFS changes before recon gets out there tomorrow afternoon (and if they find a system to upgrade) I could see the first track being towards Matagorda but with heavy emphasis on the potential GFS solution.
Pas_Bon
Posts: 309
Joined: Tue Sep 11, 2018 7:58 am
Location: League City, TX
Contact:

Ok. Enough about Harvey forecast discussion. Focus on the current storm.
Scott747
Posts: 1488
Joined: Tue Feb 23, 2010 9:56 am
Location: Freeport/Surfside Beach
Contact:

0z CMC drops the left hook around Brownsville and straddles the coastline with a depression/weak ts up through Corpus and Matagorda.
Andrew
Site Admin
Site Admin
Posts: 3440
Joined: Wed Feb 03, 2010 9:46 pm
Location: North-West Houston
Contact:

00Z UKMET still keeps it weak/into Southern Texas with a gradual turn to the northeast.
For Your Infinite Source For All Things Weather Visit Our Facebook
Scott747
Posts: 1488
Joined: Tue Feb 23, 2010 9:56 am
Location: Freeport/Surfside Beach
Contact:

0z HMON with a strong ts/borderline cane into Matagorda Bay Tuesday morning.
Andrew
Site Admin
Site Admin
Posts: 3440
Joined: Wed Feb 03, 2010 9:46 pm
Location: North-West Houston
Contact:

00Z GFS ensembles show it's the furthest east by a considerable margin. Most other members line up well with the other models of a South Texas/Central Texas landfall
Attachments
gfs-ensemble-invest94l-1631404800-1404800.png
For Your Infinite Source For All Things Weather Visit Our Facebook
Scott747
Posts: 1488
Joined: Tue Feb 23, 2010 9:56 am
Location: Freeport/Surfside Beach
Contact:

Based on the latest TWO I'd guess that even if recon doesn't find a classifiable system later this morning they will at least initiate PTC advisories at 4.
User avatar
Belmer
Global Moderator
Global Moderator
Posts: 744
Joined: Thu Jan 06, 2011 7:29 pm
Location: Dallas, TX
Contact:

Scott747 wrote: Sun Sep 12, 2021 1:10 am Based on the latest TWO I'd guess that even if recon doesn't find a classifiable system later this morning they will at least initiate PTC advisories at 4.
Agree, quite a bit of 850mb vorticity and even noted 500mb. Likely will have some good mid-level rotation by sunrise once fully emerged over BoC. Looks like whatever is trying to get organized is around 95W 19.5N.

Also, big uptick in a 'moderate to strong' tropical storm in 00z models compared to 06/12/18z. Environment looks good, but becomes questionable once it gets around 25N due to dry air and shear.
Attachments
Intensity Guidance
Intensity Guidance
Blake
Boomer Sooner
User avatar
don
Posts: 2616
Joined: Wed Feb 03, 2010 3:33 pm
Location: Heights
Contact:

The EURO seems pretty much locked in on it's general landfall area of the storm at this point.
Attachments
prateptype_cat_ecmwf.us_sc (3).png
User avatar
Belmer
Global Moderator
Global Moderator
Posts: 744
Joined: Thu Jan 06, 2011 7:29 pm
Location: Dallas, TX
Contact:

Stratton20 wrote: Sat Sep 11, 2021 11:33 pm I think with this run, we can officially throw the GFS in the trash can for this system at least, 981mb is near cat 2 strength and I really just think the GFS is overdoing this system, even the 00z ICON is more in line with the Euro solution
GFS showing a 981mb storm near TX/MX border is very reasonable. High PWs, little to no dry air, great upper-level flow and as you mentioned a few weeks ago after Ida, the northwestern Gulf remains 'undisturbed' in regards to SST's. I've learned to never count out RI when an environment supports it in the GoM. The question will be how much dry air and shear disrupts whatever is there once it approaches the TX coast. 00z GFS suggest a strengthening storm up to about 25N where shear and dry air would impede any further development and this would likely become a sloppy tropical storm with much of the moisture south and east of the center.

00z Tue PWs
00z Tue PWs
00z Tue Shear
00z Tue Shear
18z Tue PWs
18z Tue PWs
18z Tue Shear
18z Tue Shear
Blake
Boomer Sooner
Andrew
Site Admin
Site Admin
Posts: 3440
Joined: Wed Feb 03, 2010 9:46 pm
Location: North-West Houston
Contact:

don wrote: Sun Sep 12, 2021 1:32 am The EURO seems pretty much locked in on it's general landfall area of the storm at this point.
Landfall is similar but it stalls/slows the system along the coast this time instead of continuing to push inland.
For Your Infinite Source For All Things Weather Visit Our Facebook
Post Reply
  • Information
  • Who is online

    Users browsing this forum: Ahrefs [Bot], Bing [Bot] and 126 guests