2019 Tropics: Global Model Runs Discussion (Out to day 16)

[gatorcane]

GFS with genesis days 6-7 rapidly developing this into a hurricane:

[USTropics]

If the GFS is correct, we should see signs in the near future. Origins can be traced to the current frontal boundary stalled in the Midwest. Surface analysis forecasts show a shortwave trough cutting off in 24-36 hours just north of Texas that moves around the periphery of the high pressure towards the EC:



You can see this evolution in the 850mb vort loop below from the 18z run:

[gatorcane]

The Euro shows a similar evolution and path for the piece of energy that could spawn genesis. It is also possible we see some subtropical development. Looks to be a bit north of where the GFS has it at 144 hours:

[USTropics]

Seems the GFS digs the high pressure area further south than the ECMWF, resulting in a more SE motion as the shortwave trough rounds the periphery of the high pressure area. You can follow the vorticity of the shortwave trough with the high-res ECMWF run below. Subtle signs to watch for in the short-term to see which model has a more accurate grasp on the evolution.

[USTropics]

One other interesting note, the GFS has performed quite well in the last week or so when looking at anomaly correlations, catching up quickly with the ECMWF:



Below is a model verification for the GFS, ECMWF, and UKMET as well in regards to 500mb heights (red lines are previous forecasts, blue is current analysis).

GFS:


ECMWF:


UKMET:

[Hypercane_Kyle]

Looks like this upcoming trough could spin 1-2 tropical cyclones up. GFS spins one up (Barry) by 144hrs, and another by 162hrs (Chantal).

[TheStormExpert]

Watch the Tropical Atlantic also in about a weeks time for a potential brief spin up.

[chaser1]

Watch the Tropical Atlantic also in about a weeks time for a potential brief spin up.

Looking at the 850 mb GFS, there does appear to be an increase of vorticity showing up with a few tropical waves to move off the African coast during the upcoming couple of weeks. While the ITCZ does look to become a bit more active in the E. Atlantic, surface pressures still appear to be high out there for the time being. The only thing I see trying to briefly spin up that NHC has lately developed a keen interest in, might be a small T.F. (Tropical Farce) that might develop along a weak frontal boundary east of the Carolina's. Perhaps it might offer a brief 12/24 warm core with just enough convection to excite the powers that be to tag it with a name.

[Hypercane_Kyle]

00z ECMWF has a TC over the GA/SC border by 240 hours.

[drezee]

Best analog to me...

https://en.m.wikipedia.org/wiki/Tropica ... eryl_(1994)

[USTropics]

12z ECMWF has a TC over the GA/SC border by 240 hours.

I believe that was last night's 00z run, still a few hours away from the 12z run for today. GFS just started running. Last night's 00z ECMWF run at 240 hrs:

[Hypercane_Kyle]

12z ECMWF has a TC over the GA/SC border by 240 hours.

I believe that was last night's 00z run, still a few hours away from the 12z run for today. GFS just started running. Last night's 00z ECMWF run at 240 hrs:

https://i.imgur.com/Khu1sHb.png

Was a typo on my part. Edited.

[USTropics]

The past few ECMWF and GFS runs are in close agreement with the evolution of a shortwave trough breaking off from the frontal boundary over the Midwest in the next 24 hours and driving it SE around the periphery of the high pressure system towards GA and the EC. The models have bounced around as to the strength, with the 12z GFS forecasting a weaker shortwave trough stalling over GA/SC before becoming elongated and stretched out. The tail end extends into the GOM in the long range, where a weak vort signature develops. Below is a loop of this evolution:

[USTropics]

The 12z ECMWF run almost mirrors the 12z GFS run, see loop below:

[StruThiO]

 https://twitter.com/TropicalTidbits/status/1146858560187490304

[northjaxpro]

I would tend to think that if we see some type of home-grown development in the next week, I like the EURO's thinking of something possibly getting triggered in the ĢOM. GFS definitely showing different scenario with the short wave trough. We will watch and see how this plays out . Meanwhile, definitely nothing coming from out in the Tropical Atlantic anytime soon with SAL continuing to keep a lid on things out there.

[jconsor]

 https://twitter.com/yconsor/status/1146855914928037888

[northjaxpro]

https://twitter.com/yconsor/status/1146855914928037888

Well timed post after mine. This is the main reason and factor why I like the EURO's potential GOM scenario. SST's are extremely warm in the GOM currently. We will have to watch this potential very carefully next week!.

[gatorcane]

Euro ensemble mean showing lowering of pressure along the northern Gulf coast. Looks like the mean is more west than the op run:

[TheStormExpert]

Background state should become more favorable for GoM tropical shenanigans next week.

 https://twitter.com/michaelrlowry/status/1146878670944047104