ATL: DELTA - Post-Tropical - Discussion

[HurricaneAndre2008]

000
ABNT20 KNHC 042309
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Sun Oct 4 2020

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical
Storm Gamma, located just north of the Yucatan Peninsula over the
extreme southern Gulf of Mexico.

The National Hurricane Center is issuing advisories on Potential
Tropical Cyclone Twenty-Six, located over the northwestern Caribbean
Sea.
* Formation chance through 48 hours...high...near 100 percent.
* Formation chance through 5 days...high...near 100 percent.

[LarryWx]

From what I can see, conditions are PRIME up to about late Wednesday or early Thursday. The NW Caribbean can easily support a major hurricane and I wouldn't be surprised to see rapid, if not explosive, short to mid-term intensification if an LLC can solidly consolidate. However, water temperatures in the northern Gulf aren't particularly warm, perhaps due to energy used up by Sally. They are only about 25-26C offshore and even up to about 26N latitude. That could be the difference maker. Farther east (i.e. east of the western Panhandle) they are warmer.

More of an influence than Sally have been much cooler late Sep/early Oct temps over the SE US vs a month ago and vs recent years. Cooler air almost always has a major influence on N GOM temps. Remember that the primary mechanism for cooling SSTs during autumn is cooling air temps.

Don't be deceived. The N GOM temps are actually pretty close to long term averages for early October. It may not seem like it because they have been no ridiculously warm.

[TallyTracker]

With 100% development chances now, I’m expecting an 11 pm (maybe even 8 pm) upgrade to TD.

[edu2703]

 https://twitter.com/KalTellefsenWX/status/1312900034954964993

[Keldeo1997]

I might remember this wrong I'm pretty sure Teddy was maintaining CAT4 in similar water temps has what 26 is going to be dealing with in the gulf

[Hypercane_Kyle]

This one looks like it could get nasty fast, especially if the HWRF/HMON is to be belived. Gamma ramped up fast in the Caribbean and nearly became a minimal hurricane.

[MetroMike]

With 100% development chances now, I’m expecting an 11 pm (maybe even 8 pm) upgrade to TD.

Not that quickly, perhaps tomorrow late.

[aspen]

This one looks like it could get nasty fast, especially if the HWRF/HMON is to be belived. Gamma ramped up fast in the Caribbean and nearly became a minimal hurricane.

It most likely was a minimal hurricane. Recon data supported 60kt/983mb a few hours before landfall, so it likely got up to 65-70 kt. And keep in mind that Gamma had a lot less time over water than Delta will.

[MetroMike]

Will probably be a sloppy mess that won't move once it nears the coast, par for the course this season.

[TallyTracker]

With 100% development chances now, I’m expecting an 11 pm (maybe even 8 pm) upgrade to TD.

Not that quickly, perhaps tomorrow late.

The NHC’s 8 pm advisory is saying either tonight or tomorrow. It only needs to tighten up a little more and it will get the upgrade.

[Hypercane_Kyle]

This one looks like it could get nasty fast, especially if the HWRF/HMON is to be belived. Gamma ramped up fast in the Caribbean and nearly became a minimal hurricane.

It most likely was a minimal hurricane. Recon data supported 60kt/983mb a few hours before landfall, so it likely got up to 65-70 kt. And keep in mind that Gamma had a lot less time over water than Delta will.

I was moving from Illinois to Florida when this was happening, so I honestly only had the advisories to look at.

[Hypercane_Kyle]

Will probably be a sloppy mess that won't move once it nears the coast, par for the course this season.

Excluding the storms that turned into significant hurricanes as they neared the coast, of course.

[LarryWx]

Oct 1-10 TC genesis climo tracks: Note that there have been in the W Caribbean only ~37 geneses (when adding Nate and Michael) documented during Oct 1-10 since 1851 and about the same number for Oct 11-15. Yes, many were likely missed before 1960. But regardless, getting 2 during just Oct 1-10 is sort of verifying the idea that the very warm and largely untouched W Car waters in combo with ENSO based analogs (weak to moderate La Nina following a weak to moderate El Nino) was strongly suggesting that there'd be this level of activity there and for the CONUS among other locations to be vigilant:



Note also that climo says that tracks all the way to as far west as LA are very believable. I’d be extra wary of a potential landfall anywhere from LA to the FL Panhandle with there even being an outside chance as far E as the Big Bend. Regardless of the exact track, the signs are there for another big rainfall event for areas within Mobile E to Tallahassee and then inland from there into parts of the SE. Be vigilant.

[TallyTracker]

Oct 1-10 TC genesis climo tracks: Note that there have been in the W Caribbean only ~37 geneses (when adding Nate and Michael) documented during Oct 1-10 since 1851 and about the same number for Oct 11-15. Yes, many were likely missed before 1960. But regardless, getting 2 during just Oct 1-10 is sort of verifying the idea that the very warm and largely untouched W Car waters in combo with ENSO based analogs (weak to moderate La Nina following a weak to moderate El Nino) was strongly suggesting that there'd be this level of activity there and for the CONUS among other locations to be vigilant:

https://i.imgur.com/Z9UzTbN.png

This was very informative! Thanks for sharing!

[tolakram]

I had to remove over a page of posts.

I want to make this very clear. Making fun of pro mets, the NHC, or other users is not tolerated. I don't care what color your name is it will be met with a warning or suspension if it happens. Any one of you are more than welcome to disagree with a promet, the NHC, or other users but you must do so respectfully. NO EXCEPTIONS

[Keldeo1997]

Camille could actually be a good track analog for this

[DestinHurricane]

https://cdn.discordapp.com/attachments/716215692617187328/762466191579021312/image0.png

Camille could actually be a good track analog for this

Possible but I think we'll see a N or NE turn at some point rather than just NNW. I'm thinking we will see more east shifts, especially if stronger in the near term.

[MarioProtVI]

https://cdn.discordapp.com/attachments/716215692617187328/762466191579021312/image0.png

Camille could actually be a good track analog for this

Definitely not intensity-wise though unless for a minuscule chance (<0.00001%) Delta decides to completely 2020 itself and bomb to a Cat 5 which is not going to happen most likely it seems

[HurricaneAndre2008]

No depression tonight, maybe tomorrow evening

[ElectricStorm]

No depression tonight, maybe tomorrow evening

Still over 2 hours until the advisory. It might be able to get there but I think there's a better chance they'll upgrade it by morning.