ATL: GERT - Post-Tropical - Discussion

[Digital-TC-Chaser]

May get a named storm.
https://www.ventusky.com/?p=30.0;-71.5; ... =0QEQYp_5B

From my understanding icon is a GFS model core refined by dwd It has been showing
the wave close off and organise over many runs.

[xironman]

Convection is still pretty weak, but it does look a bit more like a closed low. Maybe still some dry air layers around.

[Nimbus]

Little more convection this morning than we have seen at sunrise.
Could be starting to stack up a little better so it can take advantage of the steaming SST's in the area?
NHC upped the 5 day chances to 60% last night and I would say more like 80% since there is nothing left out there to blow it apart, and the moisture content of the inflow is improving.

[cycloneye]

8 AM TWO up to 60%-70%

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Sat Aug 12 2017

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

A low pressure area located about 150 miles northeast of the Turks
and Caicos Islands has become a little better defined this morning
and the shower activity has increased somewhat since yesterday.
Conditions are gradually becoming more conducive for development,
and a tropical depression could form during the next day or two. The
low is forecast to move northwestward and then northward through the
weekend, and then turn to the northeast away from the United States
early next week.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...high...70 percent.

$$
Forecaster Avila

[GCANE]

Very strong rain-rate.
Starting to get interesting.
Going to need to fight some tough UL conditions though the next 24 hrs

[GCANE]

Improving on MIMIC-TPW

http://tropic.ssec.wisc.edu/real-time/m ... anim=html5

[GCANE]

[stormreader]

[NDG]

It finally has a very noticeable closed circulation this morning.

[tolakram]

SLIDER

http://rammb-slider.cira.colostate.edu/?sat=goes-16&sec=conus&x=8509&y=6171&z=3&im=24&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

[RL3AO]

It finally has a very noticeable closed circulation this morning.

Looks better this morning. If it can keep convection today it'll probably be a TC by tomorrow.

[NDG]

The GFS has been doing a horrible job in forecasting the upper levels, I remember that it was forecasting a sheared environment over 90L in the western Caribbean, thus it was initially not showing 90L to develop.
Now with 99L it shows an ULL to track right along on top of it all the way into the Bahamas while the Euro has been persistently showing an UL ridge to build on top of 99L and moves the ULL away from it.
My money is on the model that has been performing the best these last few days

The GFS continues to fail with forecasting upper level conditions, the weakening UL now to the NW of 99L is now being displaced by a building ridge close to 99L just like the Euro has been forecasting. Just 3 days ago the GFS was forecasting the ULL to grow in size right on top of 99L

[Nimbus]

The steering currents appear to be from the east and northeast in that GFS run?
The GFS closely matches the current water vapor loop.
Where is the digging front that is going to pull 99L north?
Typically tropical systems pump an anticyclone up over them and start gaining latitude as they reach the western periphery of that high pressure dome.
Makes sense that there will be a trough between that high and the high centered over Texas unless it bridges.

[cycloneye]

12z Best Track:

AL, 99, 2017081212, , BEST, 0, 230N, 687W, 25, 1012, LO

[Alyono]

well on its way to developing now. Could end up as the season's next hurricane. Only threat to land should be Newfoundland

[MississippiWx]

This is a tropical cyclone right now.

[wxman57]

The weak circulation center appears to be on the western side of the convection. That buoy just to the north now has ESE winds at 15 kts, and the squalls haven't reached it yet. It IS looking more impressive, though.

Here's a screenshot from my workstation. Center may be south of that buoy reporting the ESE wind - if there is a center.

[Ntxw]

Looking a lot better this morning

[wxman57]

There's a mid-level circulation that's well east of a weak LLC.

[weathaguyry]

This still seems to be moving west of North as of now, but models at 06z show a NNW movement very soon, maybe this could end up being a brush by the coast, like something weaker and a tad to the west of Bill 09'? Just a complete guess though.