ATL: GERT - Post-Tropical - Discussion

[WeatherEmperor]

https://twitter.com/MJVentrice/status/8 ... 7711593472


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[chaser1]

I'd say chances are becoming that this is more likely not to develop than to.

During a year where Atlantic tropical cyclones seem to form from as little as cruise ships making a counter clockwise turn , then add climo, dynamic conditions, broad model support, AND a strong Kelvin Wave........ (and sprinkle in a strong and westward building mid-level anticyclone) HOUSTON, we may have a problem

[wxman57]

I would say that chances are dropping given that SAL intrusion is starting to take it toll. Also note it is stretch out and no signs of consolidation. Wouldn't be surprise to see the % start dropping later this afternoon.

What SAL intrusion are you referencing?

This SAL - it's nearly completely embedded in the SAL. Looking less impressive by the hour.

[tolakram]

Good morning
Can someone please provide me with link for the spaghetti models for this invest?
thank you

On this page is one version.

https://www.tropicaltidbits.com/storminfo/#99L

[tolakram]

This SAL - it's nearly completely embedded in the SAL. Looking less impressive by the hour.

http://weather.graphics/nasa/2017080400 ... ntic_3.png

I was looking at the current CIMSS analysis which seems to show SAL well north.

[RL3AO]

Are we seeing an example of the aerosol model showing increased dust particles, but not necessarily the very dry sinking air that often accompanies them?

The air to the NE of the wave is shown to have very high amounts of dust, but the PW values are near to above normal in that area.

[GCANE]

Nicely defined warm core with this already.
LL Vorts south of 10N.
IMHO, once the LLC moves north of 10N and if can maintain convection, likley it could spin up.

[tolakram]

Add this to the mix ... will it or won't it.

 https://twitter.com/AndyHazelton/status/893206513036259328

[weathaguyry]

GFS has done a good job so far with this, it all depends if the western vort takes over, which the GFS shows happening tonight

[RL3AO]

Here's what I was referring to. You can see how dusty the air is and that is confirmed with the NASA model. You can also see that the same region to the north of the wave is fairly moist (although clearly stable).

[Siker]

I still don't know how much it matters, but comparing CIMSS 12z 850mb vorticity analysis to the 00z Euro's 12 hour forecast shows that the Euro was too ill defined with the southwestern lobe and too well defined with the eastern lobe.

[Blown Away]

If a W bound system moves above that 20/60 mark, the majority of the time it takes FL/GOM out of play, keeps mid Atlantic in play, but mostly supports a recurve away from CONUS, the historical stats overwhelmingly support that w/o the science. If this W bound system drops below that 20/60 mark the odds increase for the CONUS, but a recurve will always be the more likely track. The longer 99L takes to deepen at this point the more likely the models will dip S long term. JMHO!

[RL3AO]

I still don't know how much it matters, but comparing CIMSS 12z 850mb vorticity analysis to the 00z Euro's 12 hour forecast shows that the Euro was too ill defined with the southwestern lobe and too well defined with the eastern lobe.

I've never been able to find out, but I've always wondered if there was a first guess from the GFS that goes into that product.

[Siker]

GFS already much weaker through 12 hours. Likely conceding to the others.

Edit: Weaker but still consolidating within 24 hours.

[slamdaddy]

Not sure how much stock to put into this intensity guidance.

http://www.ral.ucar.edu/hurricanes/real ... _early.png

[RL3AO]

GFS already much weaker through 12 hours. Likely conceding to the others.

Edit: Weaker but still consolidating within 24 hours.

Still doing the same thing as recent runs. It fires new thunderstorms overnight and they coalesce into a TC. Of course, that means the run from 24 hours ago had it as a TC by this morning...so....

[Blown Away]

GFS already much weaker through 12 hours. Likely conceding to the others.

Edit: Weaker but still consolidating within 24 hours.

About the same, except 12z farther S that 6z within first 24 hrs, see if that makes a difference down the road...

[RL3AO]

As the model runs are coming in, try to keep the one-liners (e.g. 168 hrs moving NW) without images to a minimum.

[RL3AO]

GFS still develops it although it is weaker. We will see if this is the start of a trend or an adjustment towards a more realistic solution.

[Blown Away]

60 hrs... 06z had 997mb TS/Cane... 12z has 1008mb maybe TD...