ATL: ARTHUR - Post-Tropical - Discussion

[lester]

997.1 mbs found

[Aric Dunn]

pressure about 50 mile outside the center already at 1003... center pressure probably around 997

oh and all indications are its not de-coupled

recon..

060730 2809N 07907W 8433 01462 9971 +195 +061 227006 011 020 001 00

[windnrain]

Good call on 997.

[Hammy]

Shear has certainly lessened as Google Earth is showing the center inside of the 'radar eye'

edit: could be more stacked than shown as the plane looks like it just missed the center to the SW.

[Aric Dunn]

so recon confirms mlc and llc are stacked.. dry air very likely the culprit for the recent decline in convection. should come back as it works out the dry air

[lester]

TropicalTidbits: 850mb flight-level center and MSLP center align perfectly. Arthur is finally vertically stacked

:O

[Hammy]

I wonder if they'll actually find 60 mph winds out there though.

[Aric Dunn]

I wonder if they'll actually find 60 mph winds out there though.

radar velocities are not showing that.. but they often underestimate ..

061930 2744N 07835W 8431 01545 0084 +160 +042 222050 053 039 002 00


53kt FL pretty close.. though the east quad will likely have the highest winds

[lester]

50-53 kts at flight level this set

[Hammy]

Seems to have weakened if anything.

[lester]

000
URNT12 KNHC 020627
VORTEX DATA MESSAGE AL012014
A. 02/06:07:20Z
B. 28 deg 09 min N
079 deg 08 min W
C. 850 mb 1397 m
D. 35 kt
E. 294 deg 27 nm
F. 021 deg 38 kt
G. 294 deg 24 nm
H. 997 mb
I. 17 C / 1524 m
J. 20 C / 1520 m
K. NA / NA
L. OPEN NW
M. C36
N. 12345 / 8
O. 0.02 / 1.5 nm
P. AF303 0401A ARTHUR OB 05
MAX FL WIND 38 KT 294 / 24 NM 06:00:00Z

[WxEnthus]

Per VDM:

L. Eye Character: Open in the northwest
M. Eye Shape & Diameter: Circular with a diameter of 36 nautical miles (41 statute miles)

[bahamaswx]

Highest SFMR was 43kt. I don't think it's much of a stretch to call it a 50kt storm.

[Aric Dunn]

000
URNT12 KNHC 020627
VORTEX DATA MESSAGE AL012014
A. 02/06:07:20Z
B. 28 deg 09 min N
079 deg 08 min W
C. 850 mb 1397 m
D. 35 kt
E. 294 deg 27 nm
F. 021 deg 38 kt
G. 294 deg 24 nm
H. 997 mb
I. 17 C / 1524 m
J. 20 C / 1520 m
K. NA / NA
L. OPEN NW
M. C36
N. 12345 / 8
O. 0.02 / 1.5 nm
P. AF303 0401A ARTHUR OB 05
MAX FL WIND 38 KT 294 / 24 NM 06:00:00Z

nearly closed eyewall... open only nw.. dry air clearly playing out right now

[Aric Dunn]

Highest SFMR was 43kt. I don't think it's much of a stretch to call it a 50kt storm.

again east quad will have the highest wind....

[beoumont]

NOAA quite often finds higher winds than AF, we'll soon see.

[Aric Dunn]

NOAA quite often finds higher winds than AF, we'll soon see.

because they typically fly at a higher altitude.. thus reduction comes about the same..

[MaineWeatherNut]

NOAA quite often finds higher winds than AF, we'll soon see.

Only reason they find higher winds is because they fly higher up. By the time you do the correct conversion down to surface winds they should both find the same speeds if they are flying at the same time.

[chaser1]

I'm still trying to make sense of the cyclonic wobble. Gives the appearance of a vort max swinging around. Another argument for a temporary "apparent" jog to the west might also be due to the low level steering of a weaker system (weaker in terms of convective cloud mass).

All that said, if Arthur can fire up some convection and increase its inflow banding channels...than I could easily see a far more stacked storm finally getting its act together. It certainly doesnt have a lot of convection to lose though and those lower pressures won't magically maintain themselves without some fresh towers popping by daybreak.

[stephen23]

To me it looks like it swallowed the dry air hours ago. Like about 4 hours ago. It appears to me that it has almost worked all that dry air out and is starting to come around. You can see feeder bands starting to build back. It also looks like the lcc is trying to consolidate again.