ATL: FRANCINE - Models

[Steve]

Too out of range for NAM 3km and FV3 which just keep it close to Brownsville. 12km has it intensifying coming up and ends at 991. ICON out to 15 hours on TT showing stretching out and disorganization of 90L and a 1006mb low coming up from 91l. That’s visible tomorrow so we can see how it does.

[Stratton23]

Models are developing this pretty close to the mexican coast, any land interaction could greatly alter where the NE turn occurs

[Steve]

Icon going with 57 slightly weakening on fade up about vermilion parish. Drops to 988 and comes in about 991/992. Total precip maps haven’t loaded yet.

[Stratton23]

Big difference between the 00z GFS and CMC, stronger vs weaker system, pretty big implications on where it feels the influence from the shortwave trough, im leaning towards weaker mainly because shear looks pretty hostile in the nw gulf when this lifts north

[Stormcenter]

GFS 976 mb at landfall, nothing to sneeze
at IMO.

[Stratton23]

the GFS has 25-40 knots of shear over that strong hurricane, im very suspicious of a strong run like that , that kind of shear would inhibit big strengthening

[HurricaneBrain]

12z GFS had about the same peak strength (970s) right off the coast of SETX/LA so I’m not buying the whole slightly stronger system = landfall dramatically further east.

[Stratton23]

HurricaneBrian i think it also has to do with the shortwave trough, if that trends stronger or weaker, that also can change the track dramatically

[LAF92]

HurricaneBrian i think it also has to do with the shortwave trough, if that trends stronger or weaker, that also can change the track dramatically

I think timing will play a factor in this. The 00z gfs was 12 hours slower than the 18z gfs

[Steve]

the GFS has 25-40 knots of shear over that strong hurricane, im very suspicious of a strong run like that , that kind of shear would inhibit big strengthening

Gonna depend on the juxtaposition. We gotta learn new stuff with new weather patterns imho.

[Steve]

Didn’t loook at upper patterns but GFS strong Cat 1/low Cat 2 landfall @ Morgan City. CMC rides TX Coast low 990’s and comes in south of Galveston. Again ICON low 990s just se of lake Charles. NAVGEM 983 around due south of New Iberia. Good opportunity to check verifications at just under 4 days to see what got it.

[REDHurricane]

the GFS has 25-40 knots of shear over that strong hurricane, im very suspicious of a strong run like that , that kind of shear would inhibit big strengthening

Gonna depend on the juxtaposition. We gotta learn new stuff with new weather patterns imho.

Didn’t loook at upper patterns but GFS strong Cat 1/low Cat 2 landfall @ Morgan City. CMC rides TX Coast low 990’s and comes in south of Galveston. Again ICON low 990s just se of lake Charles. NAVGEM 983 around due south of New Iberia. Good opportunity to check verifications at just under 4 days to see what got it.

Agreed on the first point -- if there's one thing I've learned the past year or two, it's that the true effects of wind shear can't be accurately described with a nice simple number like the UW-CIMSS or Tropical Tidbits wind shear products show, though I won't pretend to understand exactly how all of those nuances work. But there's a reason that 99L and 90L were able to sustain consistent convection to the point of almost being worthy of TD designation despite dealing with 30+ knots of shear for several days while we've seen multiple disturbances this season (and in the past) that appear to be in a favorable <10-20 knot shear environment (e.g. the same 91L we just watched traverse the entire Caribbean in a lower shear pocket) and can't sustain any thunderstorm activity at all. Other factors, such as juxtaposition of storm direction/size/strength, shear direction, positioning/strength of other synoptic-scale entities like ULLs, troughs/ridges, ULACs, jet stream, etc. etc. also appear to have a significant impact on TC development that can't really be captured by a single "wind shear" value output.

I'm personally going to stick with ICON in the Gulf until it gives me a reason not to, it always seems to figure out these weird Gulf setups before the other models can for some reason, so that'll be my prediction for now.

[cycloneye]

 https://x.com/iCyclone/status/1832644367732936951

[cycloneye]

06z GFS.

[EasyTiger]

[Category5Kaiju]

the GFS has 25-40 knots of shear over that strong hurricane, im very suspicious of a strong run like that , that kind of shear would inhibit big strengthening

I mean, yes, but at the same time you can definitely have a cyclone that intensifies under such conditions if the shear vector is favorable (Michael and Ian come to mind), so while I don't think it's the most likely outcome here, it's something to keep in mind as it's not without precedent.

[gatorcane]

The 12Z GFS is much stronger than the 06Z so far at 973MB @66 hours.

[Stormlover70]

https://i.imgur.com/Aan7NSB.png

Y'all stay safe across the pond.

[HurricaneBrain]

GFS getting real close to major hurricane territory…

[gatorcane]

12Z GFS saved loop, much stronger than any run so far, down to 957MB: