Wx Infinity Forums

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.

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.

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.

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.........

Well 00Z GFS is interesting so far. SHows 981mb storm east of Brownsville at 48H out.

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.

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.

Will meet in the middle the models will

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

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.

Ok. Enough about Harvey forecast discussion. Focus on the current storm.

0z CMC drops the left hook around Brownsville and straddles the coastline with a depression/weak ts up through Corpus and Matagorda.

00Z UKMET still keeps it weak/into Southern Texas with a gradual turn to the northeast.

0z HMON with a strong ts/borderline cane into Matagorda Bay Tuesday morning.

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

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.

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.

The EURO seems pretty much locked in on it's general landfall area of the storm at this point.

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.

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.