ATL: HELENE - Models

[tolakram]

Seeing some of the models scrape the Yuk reminds me of the issue with a single plot hurricane model. Land interaction will tend to screw up the entire run, and if it's wrong then the final intensity will probably be wrong. Is there such a thing as ensembles for the newer HAFs models?

[NDG]

This is the strongest forecast yet by SHIPS, near Cat 4 before landfall with a fairly good chance for RI over the next 48 hrs.

[BobHarlem]

This is the strongest forecast yet by SHIPS, near Cat 4 before landfall with a fairly good chance for RI over the next 48 hrs.

https://i.imgur.com/rTImLkV.gif
https://i.imgur.com/uodsOeI.gif

[Steve]

Early cycle still likes Franklin/Wakulla

https://hurricanes.ral.ucar.edu/realtim ... _early.png

Early intensity is strong as well Think we all figured Cat 2 but reasonable shot at a 3 with some of those.

https://hurricanes.ral.ucar.edu/realtim ... _early.png

[chaser1]

This is the strongest forecast yet by SHIPS, near Cat 4 before landfall with a fairly good chance for RI over the next 48 hrs.

https://i.imgur.com/rTImLkV.gif
https://i.imgur.com/uodsOeI.gif

https://i.imgur.com/Zic63nM.png

On one hand there's a significant drop in mid level relative humidity, couple with upper level shear increasing - both right around 48 hr's. On the other hand, the storm may practically be on the doorstep to landfall.

[chaser1]

I just got off the phone with my friends in Crawfordville (Wakulla county). Everything is already closed down already and there is a mandatory evacuation order in place. I've never heard of a mandatory evacuation for a whole county?!

[gatorcane]

Anybody notice how there is a relatively sizeable difference between the GFS and ECMWF between hours 24 and 42 as far as the track once it makes the turn NE near the Yucatan with the ECMWF more to the east and the GFS more to the west? The models end up converging again around 48 hours but I do wonder if the GFS will shift more to the right during this timeframe or whether ECMWF will shift more to the left. Usually the ECMWF is on the left and the GFS is on the right.

18Z ECMWF track below:

[USTropics]

Some of us MET students at FSU (mixture of grads/undergrads) will be posting articles before the event, somewhat during, and (power permitting) afterwards. We'll be doing a mixture of current observations, some informative/teaching posts, and other cool things! If you have any suggestions or topics you want us to cover, just drop a comment or message me.

https://rcedergren8.wixsite.com/northflams/post/forecasting-helene-using-satellite-imagery-1

[sweetpea]

I just got off the phone with my friends in Crawfordville (Wakulla county). Everything is already closed down already and there is a mandatory evacuation order in place. I've never heard of a mandatory evacuation for a whole county?!

Yes this is where i live by the coast, we are leaving in the morning. Most of my neighbors are staying. Crazy

[NDG]

This is the strongest forecast yet by SHIPS, near Cat 4 before landfall with a fairly good chance for RI over the next 48 hrs.

https://i.imgur.com/rTImLkV.gif
https://i.imgur.com/uodsOeI.gif

https://i.imgur.com/Zic63nM.png

On one hand there's a significant drop in mid level relative humidity, couple with upper level shear increasing - both right around 48 hr's. On the other hand, the storm may practically be on the doorstep to landfall.

17 knots of shear parallel to its track is probably not enough to weaken it before landfall. Francine had 20-30 knots and was still able to intensify into a Cat 2 before landfall.

[Noles2016]

I just got off the phone with my friends in Crawfordville (Wakulla county). Everything is already closed down already and there is a mandatory evacuation order in place. I've never heard of a mandatory evacuation for a whole county?!

Yes this is where i live by the coast, we are leaving in the morning. Most of my neighbors are staying. Crazy

We are in Zone B... I wanted to stay, but the better half convinced me that we should head west and make a mini-vacation of it.

[BobHarlem]

0z icon is rolling, coming in a little stronger than 18z so far 959mb at 36 hours, track is about the same out to 36 hours.

[Steve]

FV3 out to 60 hours (7am cdt friday) cut off grabs Helene.

https://www.tropicaltidbits.com/analysi ... 2500&fh=60

It’s got rainfall at landfall, across N GA and W NC.
https://www.tropicaltidbits.com/analysi ... 2500&fh=60

[lsuhurricane]

0z ICON run is about 6 mb stronger than prior run.

[BobHarlem]

0z Icon with a hit near Steinhatchee this time about 10mb lower pressure than 18z on this run.

[TallyTracker]

I just got off the phone with my friends in Crawfordville (Wakulla county). Everything is already closed down already and there is a mandatory evacuation order in place. I've never heard of a mandatory evacuation for a whole county?!

Most of the County is forecast to go under water. Surge actually reaches Leon County in the worst storm scenarios (of which Helene is likely the prime example).

https://floridadisaster.maps.arcgis.com/apps/instant/lookup/index.html?appid=aa18a2d8737c4d66bb6434a09e17203a

[Steve]

0z Icon with a hit near Steinhatchee this time about 10mb lower pressure than 18z on this run.

https://i.imgur.com/C5e3tK9.png

That’s a big hit. It’s still east of most models but we’ll see.

[sweetpea]

I just got off the phone with my friends in Crawfordville (Wakulla county). Everything is already closed down already and there is a mandatory evacuation order in place. I've never heard of a mandatory evacuation for a whole county?!

Most of the County is forecast to go under water. Surge actually reaches Leon County in the worst storm scenarios (of which Helene is likely the prime example).

https://floridadisaster.maps.arcgis.com/apps/instant/lookup/index.html?appid=aa18a2d8737c4d66bb6434a09e17203a

Yeah not liking that, I am in that red area. We leave in the morning, we will see what we come back too. Most of my neighbors are staying.

[BobHarlem]

 https://twitter.com/AWxNYC/status/1838767707472150867

[BobHarlem]

0z GFS coming in about 8mb lower pressure so far than the 18z