ATL: IRMA - Models

[sma10]

 https://twitter.com/crankywxguy/status/904032478276530177

Very nice write-up! And a decidedly "uncranky" take.

[gatorcane]

Here is the 12z UKMET text input plotted out.

https://i.imgur.com/BWhSN09.jpg

What does the high and trough set up look like?

I don't know, I haven't seen the 500mb plot.

Out to 144 hours:

[chris_fit]

12 Euro Init

[gatorcane]

12Z Euro Init:

[SouthFLTropics]

Pretty good jump SW by the HWRF at 12z...You can see Puerto Rico off to the SW of the storm

[TheStormExpert]

GEFS Ensembles have been trending closer to the NE Caribbean since the 00z run.

[gatorcane]

Decent west shift by HWRF. That is Hispaniola to the SW. You couldn't see it on the 06Z run at this timeframe:

[Alyono]

HWRF narrowly keeps the hurricane force winds north of Antigua, but does bring them to St. Martin and Anguilla

[AdamFirst]

Quick thanks to the folks putting the various model runs in animated GIFs.

[AxaltaRacing24]

Slow

[sma10]

Slow

Disagree. In fact, a teensy bit faster

[TheStormExpert]

48hrs.

[Steve]

Here is the full run of the HWRF-P which is in line with most other models. Solid Cat 4 heating toward the Southern Bahamas but looks like it might pass just to the NE of them.
https://www.tropicaltidbits.com/analysi ... 0&ypos=500

Here is the simulated IR Run
https://www.tropicaltidbits.com/analysi ... 0&ypos=400

And here is the run saying why it's going to turn up Irma up and probably not hit Florida unless that flow lifts out ahead of time.
https://www.tropicaltidbits.com/analysi ... 0&ypos=600

^^^ All runs are Valid into 5 days (goes out to 126 hours).

[Blown Away]

Funny and good news if Euro went way E...

[tarheelprogrammer]

48hrs.

Sure does look like this may end up OTS. Ridge is weaker with more troughing.

[TheStormExpert]

Here is the full run of the HWRF-P which is in line with most other models. Solid Cat 4 heating toward the Southern Bahamas but looks like it might pass just to the NE of them.
https://www.tropicaltidbits.com/analysi ... 0&ypos=500

Here is the simulated IR Run
https://www.tropicaltidbits.com/analysi ... 0&ypos=400

And here is the run saying why it's going to turn up Irma up and probably not hit Florida unless that flow lifts out ahead of time.
https://www.tropicaltidbits.com/analysi ... 0&ypos=600

Looks like the trough has gone stationary and may be getting ready to lift out looking at that 12z HWRF-P loop.

[TheStormExpert]

72hrs.

[Steve]

Yeah TSE. The trough definitely comes to a stop and can't bring those screaming 50k winds further east. For others, that red ribbon you see to the west across GA is at 200 which I think is about 7 miles up.

[AxaltaRacing24]

48hrs.

Sure does look like this may end up OTS. Ridge is weaker with more troughing.

The ridge is stronger than the 00z though.

[Michele B]

Close to the islands @96 hrs position is almost on top of the Euro

Trough is strong there. Maybe it is OTS????????

If you want an out to sea scenario, you want a WEAK TROUGH!!! This is said many times, but needs to be repeated. A stronger trough is going to have a sharper tilt, if not a negative tilt. That will only bring the storm inland. A weak trough is more zonal

I hope I can shed a little light on this. Please, promets, correct me if I state this wrong:

Think of a LOW pressure trough like a bowl...it will draw the storm INTO it, like water spilling INTO a bowl.
A HIGH pressure ridge is like the bowl turned upside down. It will repel the storm AWAY from and around it.