ATL: GERT - Post-Tropical - Discussion

[Emmett_Brown]

 https://twitter.com/BigJoeBastardi/status/895601108877365248

[NDG]

It's behaving/tracking precisely as has been predicted for the past week. Still looks like it has a fair chance of becoming a TS as it recurves east of the Bahamas this weekend. I don't see any significant risk to the East U.S. Coast.

Nice view from the GOES-16 slider page. Weak LLC is easy to see.

http://wxman57.com/images/99lb.JPG

This is a first, seeing wxman57 going against no model support for development of 99L, except of course the crazy CMC but even that model has been trending weaker and weaker.

[RL3AO]

This is a first, seeing wxman57 going against no model support for development of 99L, except of course the crazy CMC but even that model has been trending weaker and weaker.

There is limited model support, but historically this is the type of wave that develops as it moves along the western side of the subtropical ridge.

[Kazmit]

Current shear map:

[Blown Away]

If 99L doesn't develop it might become the longest traveled invest in Storm2k history??

[Aric Dunn]

Looks like shear has come down some.. lets see how this reacts..

[Siker]

UKMET has this again:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 66 HOURS
FORECAST POSITION AT T+ 66 : 27.1N 71.9W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 13.08.2017 72 27.7N 73.2W 1011 24
0000UTC 14.08.2017 84 28.9N 74.2W 1010 26
1200UTC 14.08.2017 96 30.8N 74.6W 1010 34
0000UTC 15.08.2017 108 33.6N 73.6W 1009 30
1200UTC 15.08.2017 120 37.0N 70.6W 1007 33
0000UTC 16.08.2017 132 40.8N 63.3W 1003 36
1200UTC 16.08.2017 144 43.6N 54.9W 1002 35

[txwatcher91]

CMC still develops this and takes it into the Bahamas and then up right along the NC coast or slightly offshore. The GFS stalls the energy out in the Bahamas and washes it out.

[txwatcher91]

Once it gets north of PR is when some of the aggressive Euro runs had this developing. Shear is 5-10kts there and if it stays that low this could develop quickly.

[cycloneye]

2 PM EDT TWO:

Disorganized showers and thunderstorms continue in association with
a trough of low pressure located a couple of hundred miles northeast
of the northern Leeward Islands. Some slow development of this
system is possible during the weekend while the system moves
northwestward over the western Atlantic.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...medium...40 percent.

[StormTracker]

2 PM EDT TWO:

Disorganized showers and thunderstorms continue in association with
a trough of low pressure located a couple of hundred miles northeast
of the northern Leeward Islands. Some slow development of this
system is possible during the weekend while the system moves
northwestward over the western Atlantic.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...medium...40 percent.

Darn it CE, you beat me to it!

[abajan]

[WeatherEmperor]

Euro still trying to do something with 99L


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[tolakram]

Weatherbell Euro plots max wind speeds at 24 kts through 78 hours. All winds to the east / northeast side of the center.

[tolakram]

[wxman57]

ASCAT showed a great deal of precision in exactly placing it between swaths again. I'm sure there's a circulation, but it takes a little more than that to be classified as a depression. May very well become a weak "Gert" by Sunday, but it doesn't appear likely that it will impact the East U.S. Coast. Perhaps a relatively quiet next 10 days across the Atlantic?

[Steve]

CMC has been on it for at least 5 days or so. It's moved a bit more west as it has alternated closer to Bermuda and then halfway between Bermuda and the US. This time it makes a run at the Outer Banks but due to a narrow nose of the Atlantic High, just goes around the western side and pulls out. It is about to the latitude of the SC/GA border at 120 hours as 998mb - so a stronger tropical storm or possibly lesser hurricane if the background pressures in the Atlantic are particularly high as they often are in the summertime.

[Emmett_Brown]

CMC has been on it for at least 5 days or so. It's moved a bit more west as it has alternated closer to Bermuda and then halfway between Bermuda and the US. This time it makes a run at the Outer Banks but due to a narrow nose of the Atlantic High, just goes around the western side and pulls out. It is about to the latitude of the SC/GA border at 120 hours as 998mb - so a stronger tropical storm or possibly lesser hurricane if the background pressures in the Atlantic are particularly high as they often are in the summertime.

The westward trend has been interesting to watch! Not sure how good CMC has been with the overall steering patterns, however...

[Hammy]

From VIS loop it looks like any surface organization that existed the last few days just collapsed in the last few hours.

[Steve]

CMC has been on it for at least 5 days or so. It's moved a bit more west as it has alternated closer to Bermuda and then halfway between Bermuda and the US. This time it makes a run at the Outer Banks but due to a narrow nose of the Atlantic High, just goes around the western side and pulls out. It is about to the latitude of the SC/GA border at 120 hours as 998mb - so a stronger tropical storm or possibly lesser hurricane if the background pressures in the Atlantic are particularly high as they often are in the summertime.

The westward trend has been interesting to watch! Not sure how good CMC has been with the overall steering patterns, however...

Me either. I haven't even looked at 500mb or any of the other atmospheric levels because this never looked like it would be much of a threat to the US except maybe a brush by.