ATL: ROSE - Post-Tropical - Discussion

[Teban54]

Rose is looking decent tonight. The center is under the convection and it's been firing cold convection for a while now. Of course we aren't ever going to know for sure what's going on under there without recon but if this continues Rose may try to make a run at an upper TS.

I'm surprised NHC only went with 35 kts for the 11pm advisory. Rose has been firing several hot towers and seems to be trying to develop some banding. Looks rally good for a storm that's expected to peak at 45 kts.

[Sciencerocks]

[Monsoonjr99]

Shear doesn't look half bad over Rose. Could make a run at a brief hurricane if it can quickly organize a core.

[aspen]

Could be better…but it could be worse.

I think 35 kt is a little low. This could be closer to 45-50 kt.

[JRD]

Guessing there's something with the GFS cyclone phase diagram, as it shows an asymmetric shallow cold core, even when satellite indicates a tropical structure (there's some asymmetry in wind speed and precipitation though, which could be shear).

[jconsor]

 https://twitter.com/yconsor/status/1439917046607798276

[tolakram]

Rose has floater status

https://weather.cod.edu/satrad/?parms=meso-meso2-02-48-1-100-1&checked=map&colorbar=undefined

[tolakram]

saved loop

[aspen]

A blend of SATCON, ADT, and several other satellite estimates support 45-50 kt for 11am. Rose is only 35 kt as of 6am so I doubt the NHC will go as high as 50 kt for the following advisory, but maybe they’ll go 50-60kt at 5pm if Rose’s presentation improves.

Edit: still at 35 kt, which I don’t agree with. There’s no way this is weaker than the mostly exposed Peter

[tolakram]

floater sandwich

https://weather.cod.edu/satrad/?parms=meso-meso2-sandwich-48-1-100-1&checked=map&colorbar=undefined

[Teban54]

One is 45 kts, one is 35 kts. You are forgiven if you made the wrong guess which one is which.

[Iceresistance]

The NHC is having some fun with Rose right now . . .

Tropical Storm Rose Advisory Number 6
NWS National Hurricane Center Miami FL AL172021
1100 AM AST Mon Sep 20 2021

...ROSE MIGHT NOT BLOOM INTO A MUCH STRONGER STORM ...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...17.3N 33.4W
ABOUT 620 MI...1000 KM WNW OF THE SOUTHERNMOST CABO VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...NW OR 320 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES

There are a lot of thorns in the way of Rose blossoming into a
stronger storm. Increasing shear and drier mid-level air are on
the way for tonight, competing against the somewhat warm SSTs.
Thus Rose has about a day to flower into a moderate tropical storm,
and no significant change was made to the short term forecast. At
longer range, stronger shear and dry air should pull the petals off
Rose one-by-one, causing the cyclone to slowly weaken. The new
forecast is similar to the previous one, with some small 5-kt
downward adjustments. Rose could even shrivel up into a remnant
low by day 5, but that's not shown yet in the forecast.

[Sciencerocks]

[ElectricStorm]

I'm gonna have to disagree with the NHC on this one, I think this is stronger than 35kts. ADT is up to 53kts and while that might be a bit too high, it's probably closer to reality than 35kts is. This just doesn't seem like a minimal TS to me.

[Teban54]

I'm gonna have to disagree with the NHC on this one, I think this is stronger than 35kts. ADT is up to 53kts and while that might be a bit too high, it's probably closer to reality than 35kts is. This just doesn't seem like a minimal TS to me.

ASCAT earlier today seemed to show the LLC at the SE tip of the convection with no 35kt wind barbs. Hard to believe given the satellite presentation, but indeed that's a pretty convincing reason for going lower than 53 kts. I do think 35 kts is too low though.

[ElectricStorm]

I'm gonna have to disagree with the NHC on this one, I think this is stronger than 35kts. ADT is up to 53kts and while that might be a bit too high, it's probably closer to reality than 35kts is. This just doesn't seem like a minimal TS to me.

ASCAT earlier today seemed to show the LLC at the SE tip of the convection with no 35kt wind barbs. Hard to believe given the satellite presentation, but indeed that's a pretty convincing reason for going lower than 53 kts. I do think 35 kts is too low though.

Yeah I'd probably go with 45kts. Nice blend between the two

[Sciencerocks]

[aspen]

The NHC is still solely relying on ASCAT, it seems. Still at 35 kt on the 18z best track. ASCAT has a low bias so this is probably a little stronger.

[AnnularCane]

Too bad they can't send recon out there.

[Sciencerocks]

I'll agree with the 45 knots!