ATL: SAM - Remnants - Discussion

[InfernoFlameCat]

Trends looks good for it to get to Cat 5

Maybe. I need to see deeper convection before I fall on the 5 train.

[storminabox]

Trends looks good for it to get to Cat 5

Maybe. I need to see deeper convection before I fall on the 5 train.

I personally don’t see it becoming a 5, but I’d be happy to proven wrong! (Since only the fishes are getting impacted)

[Iceresistance]

They literally said this in the Discussion:

It sounds like a broken record, but there are no changes to the forecast during the
first few days as model guidance is in excellent agreement on a
gradually rightward-curving track, passing a couple of hundred n mi
or more east of Bermuda.

[grapealcoholic]

Trends looks good for it to get to Cat 5

Maybe. I need to see deeper convection before I fall on the 5 train.

Yea structure wise it looks much better than earlier. I think convection will come next

[Sciencerocks]

[Teban54]

Trends looks good for it to get to Cat 5

Maybe. I need to see deeper convection before I fall on the 5 train.

I mean, deep convection isn't there probably because this is not a Cat 5 yet. I expect convective bursts to come shortly if Sam is still intensifying.

[ElectricStorm]

940.6mb extrap on the first pass

[us89]

al182021 SAM 20210930 0000 20.3 -58.0 L HU 125 940

00z point revised from 120kt/942mb to 125kt/940mb.

[ElectricStorm]

Almost 140kt FL winds. SFMR is much lower but most of them are flagged

[Teban54]

Almost 140kt FL winds. SFMR is much lower but most of them are flagged

Due to SFMR's high bias, at this point it's becoming less useful if not thrown out of window entirely.

[grapealcoholic]

That's a thick band of 135+ FL. Just needs to tighten up

138 107 000 05
139 110 000 05
139 /// /// 03
137 104 000 03
134 101 000 05

[ElectricStorm]

Eye drop supports 942mb

[Hammy]

Almost 140kt FL winds. SFMR is much lower but most of them are flagged

Due to SFMR's high bias, at this point it's becoming less useful if not thrown out of window entirely.

Seems they're already doing so--would explain why they use flight wind reduction above a certain point.

[NotoSans]

The large discrepancy between SMFR and flight-level winds can be explained by two factors: (a) deep convection is not particularly strong at the moment, so winds may not be effectively mixing down to the surface; (b) Sam has just completed an ERC, and it will take time for the surface wind field to respond.

NHC’s 125kt is a good compromise.

[InfernoFlameCat]

Convection is slowly cooling...
Exciting!

[grapealcoholic]

It's forecast to pass over a warm eddy in a few hours

[Extratropical94]

938.3 mb extrapolated, 128kt FL NW, 139kt FL SE

[kevin]

Wow, new pass 934.5 mbar also with 139 FL winds and that pressure was with 35.8 kt Est. Sfc. Wind. So current intensity is at least 935mb/125kt using a 0.9 conversion factor. This is definitely deepening very rapidly and I think it puts a cat 5 back on the table.

[grapealcoholic]

[Teban54]

Wow, new pass 934.5 mbar also with 139 FL winds and that pressure was with 35.8 kt Est. Sfc. Wind. So current intensity is at least 935mb/125kt using a 0.9 conversion factor. This is definitely deepening very rapidly and I think it puts a cat 5 back on the table.

Eye drop at 938/14 so not as crazy, but if the deeping rate of ~1.7mb/hr continues, Sam might hit the MPI again some time during the day.

It seems that the impressive 150kt winds at ~925mb are not quite mixing down to the surface. Probably need more intense convection for that.