ATL: FLORENCE - Post-Tropical - Discussion

[seahawkjd]

164 mph?! Really? Unflagged? Would the NHC likely consider that or be generous with her strengthening?

At flight level though. What is the reduction for a strong this strong from flight level to surface?

[meriland29]

164 mph?! Really? Unflagged? Would the NHC likely consider that or be generous with her strengthening?

At flight level though. What is the reduction for a strong this strong from flight level to surface?

Forgive me, I don't know

[PavelGaborik10]

Hasn't even closed off it's eyewall to the N and is already starting to intensify. Hope this isn't a sign of what's to come later today, yikes.

[GCANE]

Recon just reported a closed eye.

[meriland29]

I don't see any signs of her north closing off..and its been pretty defined for a hour or so...

[PavelGaborik10]

I don't see any signs of her north closing off..and its been pretty defined for a hour or so...

Recon just reported she closed it off.

[reds37win]

Check this out..

http://tropic.ssec.wisc.edu/real-time/m ... 2hr_12.gif

Florence is trolling us. That last image of the center looks like the symbol for a hurricane.

[supercane4867]

164 mph?! Really? Unflagged? Would the NHC likely consider that or be generous with her strengthening?

At flight level though. What is the reduction for a strong this strong from flight level to surface?

The standard reduction factor is 0.8-0.9. However this doesn’t apply to storms undergoing EWRC

[meriland29]

So that math would put her somewhere around 150-153mph (?) ....I mean despite the erc

[dukeblue219]

164 mph?! Really? Unflagged? Would the NHC likely consider that or be generous with her strengthening?

At flight level though. What is the reduction for a strong this strong from flight level to surface?

The standard reduction factor is 0.8-0.9. However this doesn’t apply to storms undergoing EWRC

The easy rule of thumb for casual observers is to take the flight level winds in KNOTS and call it the surface winds in MPH. It's close enough, and these are raw data after all. The raw HDOB data provides 10-sec peak FL wind and 30-sec averaged FL wind, so it'd be better to work with the 30-sec averaged value if you're going to do that.

Finally, the "flagged" commentary usually refers to SFMR data, which is an attempt to measure surface windspeed from above. Those data points of course don't need the same conversion, but can be very sketchy depending on the rain rate in particular (which is why they are often flagged as suspect).

[tolakram]

[GCANE]

[StormPyrate]

The eye is clearing out

[tolakram]

292
URNT12 KNHC 111255
VORTEX DATA MESSAGE AL062018
A. 11/12:31:50Z
B. 26.51 deg N 064.84 deg W
C. 700 mb 2668 m
D. 951 mb
E. 165 deg 8 kt
F. CLOSED
G. C32
H. 108 kt
I. 063 deg 19 nm 12:26:00Z
J. 150 deg 143 kt
K. 062 deg 21 nm 12:25:00Z
L. 107 kt
M. 232 deg 17 nm 12:37:00Z
N. 330 deg 108 kt
O. 232 deg 17 nm 12:37:00Z
P. 12 C / 3048 m
Q. 15 C / 3049 m
R. 7 C / NA
S. 12345 / 07
T. 0.02 / 2 nm
U. AF308 0706A FLORENCE OB 15
MAX FL WIND 143 KT 062 / 21 NM 12:25:00Z
MAX FL TEMP 16 C 068 / 13 NM FROM FL CNTR
;

[plasticup]

https://i.imgur.com/tQdDjqe.gif

That cleared beautiful. I don't think I've ever seen an eye formation quite like that.

[WYNweather]

Conditions at Buoy 41049 as of 1310 GMT on 09/11/2018

Significant Wave Height Significant Wave Height (WVHT): 21.7 ft
Swell Height Swell Height (SwH): 16.1 ft
Swell Period Swell Period (SwP): 10.0 sec
Swell Direction Swell Direction (SwD): SSE
Wind Wave Height Wind Wave Height (WWH): 14.4 ft

https://www.ndbc.noaa.gov/images/buoyca ... 1_1210.jpg

[Maryellen46]

Thoughts are with everyone who is in harms way.

[longhorn2004]

Would not the Appalachian mountains weaken Florence quickly? The rain will still be a problem.

[cheezyWXguy]

951mb seems weirdly high for a storm that just increased in size, that had a pressure in the low 940s yesterday.

[SconnieCane]

Would not the Appalachian mountains weaken Florence quickly? The rain will still be a problem.

The Appalachians are further west in NC, not near the coast.