ATL: GERT - Post-Tropical - Discussion

[boca]

99L looks way to elongated to consolidate,but it's still a strong tropical wave

[OuterBanker]

Models have trashed it. I see no llc volts. But, is there a much dance starting around 37w 10n?

[OuterBanker]

Vorts not volts. #!*/# autospell!

[MGC]

99L is a train wreck this morning.....MGC

[Frank2]

Wide view (updated every 3 hours):

http://www.ssd.noaa.gov/PS/TROP/Basin_Atlantic.html

[Emmett_Brown]

Still looks like crapola (pardon my French). I don't see any more favorable environment ahead of it. Don't know what the NHC folks are looking at to keep development chances so high.

Models agree with you for next 3-4 days, then it seems pretty favorable if 99L can miss the big islands... Amateurs & Pro's heavily rely on models especially long range, so can't totally discount it, IMO.

I'm not discounting all the models, just the GFS, which has done poorly with the upper-air pattern across the tropics. The GFS has been predicting a favorable environment where there is none. During the burst of activity in the East Pac, the GFS kept forecasting widespread sinking air (unfavorable). I have no confidence in this "upgraded" GFS.

The NHC really has no reason to significantly drop percentages of development. They work for the general public, who can't "fire" them if they spend millions taking precautions for a storm that doesn't develop. I've had to go before major clients and explain why we thought a disturbance could develop in the Gulf (when it didn't develop). It's easy when there's no risk for being wrong. There's no harm in keeping the percentages high so that people in the eastern Caribbean will continue to monitor this wave. Private companies just don't have that luxury.

This explains your more bearish tendencies, but it's ok, I think your contrarian point of view is healthy, especially since it is backed up with science, and observations of "what is really happening now", instead of model fantasy.

[Bhuggs]

I know euro just kills it straight up, but GFS keeps hinting in some runs that if the energy from the wave avoids the islands maybe a bit south or a bit north this thing has a shot in the gulf. Is this realistic or am I just looking to much into it? I don't remember which runs they were but yesterday one had it going just south of the big islands and then reforming to strike LA and then a run of it splitting FL and Hispaniola

[cycloneye]

12z GFS joins ECMWF with no development.

[BobHarlem]

12GFS keeps this very weak, it may get depression, but even that seems to be a stretch on this run, it does miss Hispaniola to the north on this run, so what happens after 144 hours may be interesting.

[Ptarmigan]

Those forecast models flip flop. Yesterday, it was major hurricane. Now, it is tropical storm.

[abajan]

Seems to me, convection is increasing and starting to consolidate. Not sure:

[boca]

It looks like there are several vorts which one do you think is consolidating? 99L really is a mess

[CFLHurricane]

Seems to me, convection is increasing and starting to consolidate. Not sure:

It looks like the eastern vort is taking over. Maybe we'll finally get some quality forecasting from the models once consolidation is complete.

[cycloneye]

2 PM TWO down to 30%-50%

Disorganized showers and thunderstorms continue in association with
an elongated area of low pressure that extends more than a thousand
miles southwest of the Cabo Verde Islands. Although this system
has failed to consolidate so far, environmental conditions appear
conducive enough to support some development while this system moves
west-northwestward across the tropical Atlantic Ocean at about 15
mph.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...medium...50 percent.

[tarheelprogrammer]

Shear seems low, dry air seems minimal, and movement speed is only 15mph. So, why is this struggling to get going?

[blp]

Through 72hrs Euro holding on to vorticity a little more versus last run which had dissipation.

[gatorcane]

Yes 12Z ECMWF vort is strongest it has been in several runs:

[WeatherHoon]

Shear seems low, dry air seems minimal, and movement speed is only 15mph. So, why is this struggling to get going?

Because it's large and elongated.

[tarheelprogrammer]

Shear seems low, dry air seems minimal, and movement speed is only 15mph. So, why is this struggling to get going?

Because it's large and elongated.

Is that truly it? Also, why do the ECMWF and GFS kill it in the long range?

[gatorcane]

12Z ECMWF just NE of Northern Lesser Antilles at 120 hours. Vort is a little more defined than 00Z and slightly more northeast: