ATL: DEBBY - Models

[Jr0d]

Trough has been digging south into the gulf not unlike Ian but Debbie is a shallower system ATM so may continue WNW rather than making the unexpected track shift east.

If it remains weak..as (future)Debbie strengthens later today it will feel the trough more and more.

I did notice the mesoscale models (ie NAM) was backed off intensity from this morning with a slight shift west, with the center consolidating further west and later. They are not reliable for tropical storms, it is helpful to see how they are trending, especially with the global hurricane models struggling largely because of the current broadness of the low pressure. At least that my amateur opinion.

Eagerly waiting the GFS's hurricane model to finish running, but I think it will continue to struggle until we can get a well defined center.

[N2FSU]

12z GFS
west shift and slightly stronger:

[ElectricStorm]

12z Hurricane models weaker, with only the HWRF now showing a minimal hurricane. The rest have mid-strong TS. All four have it struggling for at least the next 24 hours before finally ramping up right before landfall. Seems pretty reasonable to me

[tronbunny]

Thank goodness it's early, because this looks way overdone

12z GFS https://uploads.tapatalk-cdn.com/20240803/0ea83bacf3f35bd767b2012d2a4fdd68.jpg
west shift and slightly stronger:

[LarryWx]

12Z Euro has just about as bad a huge rainfall total for SAV-CHS as 0Z had (15”+) (slightly lower most of corridor but still with insane max ~22”centered on HHI/Beaufort). Also, again a cat 1 H hits CHS.

[Stratton23]

HWRF does a big loop and gets back into the gulf again after moving in land in georgia

[Steve]

Most models hadn’t shown a loop back to the gulf since midweek more going with smaller loops or stalls in the sw Atlantic. I’m discounting a little but I’m sure it’s a function of HWrF at 500.


Early cycle 18z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late eps 12z
https://hurricanes.ral.ucar.edu/realtim ... l_late.png

[Nimbus]

Most models hadn’t shown a loop back to the gulf since midweek more going with smaller loops or stalls in the sw Atlantic. I’m discounting a little but I’m sure it’s a function of HWrF at 500.


Early cycle 18z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late eps 12z
https://hurricanes.ral.ucar.edu/realtim ... l_late.png

That was my question this morning... answered.
NHC statements warned they were not sure whether the track was going to stay over land or move back over water later in the forecast.

[Steve]

NAMs 12km has 992 near landfall and the always aggressive 3km has it down to 983

None of the intensity modes (early cycle) take it past TS but Ship.

[Steve]

Most models hadn’t shown a loop back to the gulf since midweek more going with smaller loops or stalls in the sw Atlantic. I’m discounting a little but I’m sure it’s a function of HWrF at 500.


Early cycle 18z
https://hurricanes.ral.ucar.edu/realtim ... _early.png

Late eps 12z
https://hurricanes.ral.ucar.edu/realtim ... l_late.png

That was my question this morning... answered.
NHC statements warned they were not sure whether the track was going to stay over land or move back over water later in the forecast.

Right. Some of the morning models were trending a little more inland as it came up but obviously we’ll have to wait and see with tonight’s runs if they think Debby gets offshore. Possibly 3 landfalls are on the table but ?

[Nimbus]

NAMs 12km has 992 near landfall and the always aggressive 3km has it down to 983

None of the intensity modes (early cycle) take it past TS but Ship.

I expect to see surface pressure drops between passes when recon gets in there.
Maybe 1002 MB at the center now if the recent ships report was accurate.
Levi mentioned some dry shear yesterday, but that was assuming the trough picked Debby up before landfall..

[Emmett_Brown]

18Z GFS is a little weaker, and a little W of the 12Z, landfalls in Apalachee Bay, so the W trend continues

[mitchell]

What a crazy set of model outputs over the past 36 hours. Everything under the sun.
The 18z GFS has it on Thursday about 200 miles from where it started on Monday morning.

[JtSmarts]

That GFS gives Debby about 36 hours over water between 1 and 2nd landfalls, thankfully GFS doesn't strengthen in rapidly during that time, but not a fan of her having that much Gulfstream time.

[BobHarlem]

0z earlies with a right shift, both in Florida landfall and into Atlantic. (HWRF still the crazy uncle)

[ElectricStorm]

18z HWRF, HAFS-A and HAFS-B have a minimal Cat 1 before landfall. HMON the weakest this cycle with a strong TS. Overall this cycle is pretty similar to the previous few cycles

[Steve]

18z HWRF, HAFS-A and HAFS-B have a minimal Cat 1 before landfall. HMON the weakest this cycle with a strong TS. Overall this cycle is pretty similar to the previous few cycles

00z NAM 12km gets it to 984 vs 987 at 18z. 3km likes Wakulla County a hair west than I guessed. 3km gets to 960 which is a big stretch but expected for it. FV3 which is often decent to look at is squirreled this run. ICON up in a bit.

[chaser1]

Yeah, I think I'll refrain from sending the 3K NAM to my Crawfordville friends right now lol. Well, far enough away from the coast to not worry about storm surge but that track would definately knock down a bunch of Pines and I'm sure the electricity too

[Steve]

Icon confirming a rainmaker.

https://www.tropicaltidbits.com/analysi ... 80400&fh=0

[Hurricane Mike]

Even if Debby moves offshore, the slow motion will still make this a rainmaking flood threat.