ATL: MARIA - Post-Tropical - Discussion

[Aric Dunn]

NW quadrant, unflagged 60, 64 knot SFMR winds, I would go with 60 knots.

AF303 0115A MARIA HDOB 20 20170917
174730 1353N 05706W 6970 03096 9977 +103 +102 072053 054 053 008 00
174800 1352N 05705W 6970 03089 9986 +105 +105 074055 055 054 012 00
174830 1351N 05704W 6971 03084 9981 +105 +105 072053 056 063 015 03
174900 1350N 05703W 6967 03083 9978 +106 +106 075046 048 062 018 03
174930 1349N 05701W 6973 03071 9968 +114 +114 080055 059 060 023 00
175000 1348N 05700W 6964 03075 9955 +115 +115 080049 057 062 021 03
175030 1347N 05659W 6964 03061 9940 +121 +121 084046 051 062 022 03
175100 1345N 05659W 6970 03046 9903 +123 +123 073041 043 064 013 00

yep that should be sufficient for a upgrade.

[NDG]

Surface pressure is probably going to be near 988-990 mb from dropsonde.

75330 1336N 05657W 6968 03034 9858 +138 +109 265013 016 020 000 00

[GCANE]

Looks like they went thru the hot tower.

[GCANE]

Nice cirrus anvil from that tower.

Example of what it would like from the plane.

[Craters]

Looks like they went thru the hot tower.

I'm sure that was a fun part of the ride...

[Aric Dunn]

Center just barely starting to come into view

http://barbadosweather.org/Composite/ki ... site=Sabre

[GCANE]

Looks like they went thru the hot tower.

I'm sure that was a fun part of the ride...

I would finish my beer before entering it.

[GCANE]

Product: Air Force Vortex Message (URNT12 KNHC)

A. Time of Center Fix: 17th day of the month at 17:53:10Z
B. Center Fix Coordinates: 13°38'N 56°57'W (13.6333N 56.95W)

D. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 64kts (~ 73.6mph)

H. Minimum Sea Level Pressure: 986mb (29.12 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 10°C (50°F) at a pressure alt. of 3,046m (9,993ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 16°C (61°F) at a pressure alt. of 3,038m (9,967ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 9°C (48°F)

L. Eye Character: Closed
M. Eye Shape: Elliptical (oval shaped)
M. Orientation of Major Axis in Elliptical Eye: 90° to 270° (E to W)
M. Length of Major Axis in Elliptical Eye: 28 nautical miles (32 statute miles)
M. Length of Minor Axis in Elliptical Eye: 16 nautical miles (18 statute miles)

[GCANE]

[GCANE]

Rain rate about 22.5 mm/hr in the tower.
Nothing close to a Cat 4, but respectable.

[chaser1]

Slow and steady as she goes. I'd guess that Maria's steadily increasing organization along with present recon reports, might have NHC upgrade Maria to a hurricane. There still appears to be a bit of (diurnal?) bursting taking place, perhaps a result of a bit of strong southerly 200mb shear taking place. Overall, I wouldn't necessarily agree that conditions are ripe for RI at this time but at the same time conditions seem to be more than conducive for slow and steady intensification. Based on that along with the storms proximity to the Islands, I'd say it would seem more than safe to assume that the Leewards and Virgin Islands all need to prepare for hurricane conditions. Even if NHC were to bring Maria up to 70mph , its practically splitting hairs at this point and they'd probably have that much more evidence by tomm. to classify her a hurricane. My guess however is that they'll upgrade Maria at 5:00 with a bit more sampling of the bands in the northeastern quad. Looking at the 200mb charts alone, I'd say that RI might well be more a threat in about 3-4 days (just where NHC projects its approach to Puerto Rico as a Cat. 3).

[NDG]

Closed eye, and they kept the 64 knot SFMR winds.

URNT12 KNHC 171811
VORTEX DATA MESSAGE AL152017
A. 17/17:53:10Z
B. 13 deg 38 min N
056 deg 57 min W
C. 700 mb 2992 m
D. 64 kt
E. 346 deg 7 nm
F. 079 deg 59 kt
G. 336 deg 11 nm
H. 986 mb
I. 10 C / 3046 m
J. 16 C / 3038 m
K. 9 C / NA
L. CLOSED
M. E09/28/16
N. 12345 / 07
O. 0.02 / 1.5 nm
P. AF303 0115A MARIA OB 08
MAX FL WIND 59 KT 336 / 11 NM 17:49:30Z
CNTR DROPSONDE SFC WIND 085 / 3 KT

[cycloneye]

18z Best Track up to Hurricane.

AL, 15, 2017091718, , BEST, 0, 136N, 570W, 65, 986, H

[wxman57]

18z Best Track up to Hurricane.

AL, 15, 2017091718, , BEST, 0, 136N, 570W, 65, 986, H

That was before recon got there. So far, max of about 50 kts.

[wxman57]

NW quadrant, unflagged 60, 64 knot SFMR winds, I would go with 60 knots.

AF303 0115A MARIA HDOB 20 20170917
174730 1353N 05706W 6970 03096 9977 +103 +102 072053 054 053 008 00
174800 1352N 05705W 6970 03089 9986 +105 +105 074055 055 054 012 00
174830 1351N 05704W 6971 03084 9981 +105 +105 072053 056 063 015 03
174900 1350N 05703W 6967 03083 9978 +106 +106 075046 048 062 018 03
174930 1349N 05701W 6973 03071 9968 +114 +114 080055 059 060 023 00
175000 1348N 05700W 6964 03075 9955 +115 +115 080049 057 062 021 03
175030 1347N 05659W 6964 03061 9940 +121 +121 084046 051 062 022 03
175100 1345N 05659W 6970 03046 9903 +123 +123 073041 043 064 013 00

yep that should be sufficient for a upgrade.

I don't like seeing SFMR winds a lot higher than FL winds, and near heavy squalls. I still don't trust those SFMR winds in heavier squalls. I'd say 50-55 kts is more likely.

[NDG]

18z Best Track up to Hurricane.

AL, 15, 2017091718, , BEST, 0, 136N, 570W, 65, 986, H

That was before recon got there. So far, max of about 50 kts.

Nope, 986 mb reading was by the recon, before recon they were estimating 994 mb at 2 PM advisory.


2:00 PM AST Sun Sep 17
Location: 13.6°N 56.9°W
Moving: WNW at 15 mph
Min pressure: 994 mb
Max sustained: 65 mph

[Aric Dunn]

NW quadrant, unflagged 60, 64 knot SFMR winds, I would go with 60 knots.

AF303 0115A MARIA HDOB 20 20170917
174730 1353N 05706W 6970 03096 9977 +103 +102 072053 054 053 008 00
174800 1352N 05705W 6970 03089 9986 +105 +105 074055 055 054 012 00
174830 1351N 05704W 6971 03084 9981 +105 +105 072053 056 063 015 03
174900 1350N 05703W 6967 03083 9978 +106 +106 075046 048 062 018 03
174930 1349N 05701W 6973 03071 9968 +114 +114 080055 059 060 023 00
175000 1348N 05700W 6964 03075 9955 +115 +115 080049 057 062 021 03
175030 1347N 05659W 6964 03061 9940 +121 +121 084046 051 062 022 03
175100 1345N 05659W 6970 03046 9903 +123 +123 073041 043 064 013 00

yep that should be sufficient for a upgrade.

I don't like seeing SFMR winds a lot higher than FL winds, and near heavy squalls. I still don't trust those SFMR winds in heavier squalls. I'd say 50-55 kts is more likely.

I agree Im not overly convinced of SFMR yet either to many discrepancies over the years.. but the NHC will follow it as they always do.

as we have just seen ... 5pm will be a hurricane..

[Aric Dunn]

the convective pattern around the cetner has become much improved over the last few hours. looks like there is still a little dry slot but does not seem to be affecting the building core as of yet.

[supercane4867]

A 986mb pressure and 50tk tropical storm don't usually come together in this part of deep tropics. Most 50kt TS in the area were around 1000mb.

[EquusStorm]

Yeah, I was also gonna suggest the 986 would lend more credence to their decision. That's rather low for a deep tropics TS.