ATL: HARVEY - Post-Tropical - Discussion

[Thetxhurricanemaster]

Pretty obvious on VIS, west winds south of the convection.

Yeah no doubt recon will head in later and find a tropical storm

[tropicwatch]

Morning satellite imagery shows that shower activity associated
with a low pressure system centered about 550 miles east of the
Lesser Antilles has become better organized overnight, and buoy
data indicates that the circulation is becoming better defined.
Environmental conditions appear generally conducive for development,
and a tropical depression could form later today or tonight as the
system moves westward at about 15 mph. Regardless of development,
locally heavy rainfall and gusty winds are expected to spread across
portions of the Lesser Antilles and the eastern Caribbean Sea
tonight and Friday, and interests in these areas should monitor the
progress of this system. An Air Force Reserve Hurricane Hunter
aircraft is scheduled to investigate the disturbance this afternoon.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...90 percent.

[GCANE]

Higher cirrus building at 13.5N 54.5W

[weathaguyry]

what time does recon fly out today?

[Digital-TC-Chaser]

estabishing two outflow channels ?

[GCANE]

what time does recon fly out today?

1800Z

[Gustywind]

000
AXNT20 KNHC 171020
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
620 AM EDT Thu Aug 17 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through
1015 UTC.

...SPECIAL FEATURES...

A 1008 mb low is located about 475 nm east of the Lesser Antilles
near 13N52W. Intrusion of Saharan dry air and dust to its
environment is observed in GOES-16 experimental imagery and CIRA
LPW imagery, however the system continue to show signs of
organization. This being favored in part by low vertical wind
shear. Scattered moderate convection and isolated tstms are within
220 nm W semicircle from low center. Upper-level winds are
forecast to become more conducive for development during the next
day or so while the low moves westward across the tropical
Atlantic Ocean, crossing into the Caribbean Sea on Friday.
Regardless of development, locally heavy rainfall and gusty winds
are expected to spread across portions of the Lesser Antilles on
Thursday night and Friday. This system has a medium chance of
becoming a tropical cyclone in the next two days.

[Alyono]

does not appear closed yet. Seeing the vort max at 13.3N, 53.5W. This is well east of the convection.

[tolakram]

SLIDER. LLC looks pretty good, convection sheared west but new storms firing over the center.

http://rammb-slider.cira.colostate.edu/?sat=goes-16&sec=full_disk&x=17543&y=8117&z=4&im=12&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=0&p%5B0%5D=1&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=0&mouse_draw=0&s=rammb-slider

[banksmanforever]

what time does recon fly out today?

1800Z

A little late for those in Barbados

[GCANE]

Vis is showing a tight surface circulation just north of the CoC.
ADT has a new tower going off very close and just west of the CoC.

[GCANE]

Looks like remnant cirrus over the CoC is clearing out from the updraft of a couple towers firing off on the immediate east and west side of the CoC.

[GCANE]

All current models have this as a warm core.
AMSU is showing 0.5C

[GCANE]

Looks like they relocated the CoC slightly to the SE.

[SouthDadeFish]

If I had to guess, I would say the circulation is closed. Would like to see an ASCAT pass though to confirm. This disturbance has exceeded my expectations so far. I agree with the NHC in raising the development percentages. This case also closely follows Dr. Michael Ventrice's research that TC genesis is likely 2 days after the passage of a convectively coupled Kelvin wave.

[ronjon]

Looks like RECON timing will be perfect with 91L as its scheduled for today.

[MGC]

91L is currently likely a TC. Recon will determine its intensity....MGC

[MississippiWx]

If I had to guess, I would say the circulation is closed. Would like to see an ASCAT pass though to confirm. This disturbance has exceeded my expectations so far. I agree with the NHC in raising the development percentages. This case also closely follows Dr. Michael Ventrice's research that TC genesis is likely 2 days after the passage of a convectively coupled Kelvin wave.

I was criticizing Ventrice a few weeks ago. Must say he has been very accurate with tropical development forecasts this season, moreso than others. Major props to him.

Anyway, I agree that the circulation is closed. Recon will confirm later.

[gatorcane]

Floater loop, looking better and better:
http://rammb.cira.colostate.edu/ramsdis ... display=12

[tropicwatch]

ASCAT this morning was in between 91L and 92L. What is the deal?:(