ATL: SALLY - Post-Tropical - Discussion

[GCANE]

5000 CAPE over S FL with cumulus building.
Going to see a large blowup of convection in a few hours.
Should take a good chunk out of the PV streamer currently holding back intensification of 96L.
Going to increase chances of stronger intensification once 96L gets into the GoM.

[jlauderdal]

Mission status for the Hurricane Hunters have yet to be updated for today. Would be nice if they could schedule a mission for today.

There really isn't much for them to do except burn up some aviation fuel. Its a wave axis, nothing more and we will have ground obs as it moves over Florida.

[3090]

5000 CAPE over S FL with cumulus building.
Going to see a large blowup of convection in a few hours.
Should take a good chunk out of the PV streamer currently holding back intensification of 96L.
Going to increase chances of stronger intensification once 96L gets into the GoM.

https://i.imgur.com/YioYkKU.gif

Are there weather conditions us non professionals are unaware of in the GOM that could hinder an intensification? To me it APPEARS the environment in the GOM is prime for intensification. But how intense?

[jlauderdal]

5000 CAPE over S FL with cumulus building.
Going to see a large blowup of convection in a few hours.
Should take a good chunk out of the PV streamer currently holding back intensification of 96L.
Going to increase chances of stronger intensification once 96L gets into the GoM.

https://i.imgur.com/YioYkKU.gif

no surprise on the CAPE, sun is out in full force after a morning of mostly cloudy skies.....naples area is in for a pounding after 3 pm

[MississippiWx]

I am thoroughly impressed at the rate of organization of this disturbance. It was an area of scattered thunderstorms yesterday with barely any surface reflection. Currently, it appears to be on the cusp of becoming a tropical cyclone. This area has my full attention all the sudden. I’d be wary of a mid-grade TS in Florida over the weekend at this rate.

[tiger_deF]

Convection is warming on the east and cooling closer to the coc, a good sign that it is continuing to consolidate

[weeniepatrol]

Unsure if this has been posted yet

[Aric Dunn]

Definitely westerly inflow between Andros and the Keys on satellite and radar. LLC likely developing rather quickly somewhere within that central convective mass around Nassau and northern Andros.

may see a TD by 11 tonight

[Michele B]

[...]

[...]
0-49 are TCs, STCs, or potential TCs. Basically these are the numbers we use starting with TDs in the Atlantic (TD01, TD02, TD03, etc.). In fact, the ATCF is hard coded to only go up to 49. If we were to ever get up to 49 systems in one year, we would actually start over at TD01 for number 50.
[...]

Interesting, I did not know that this was the standard procedure.

Not to mention, HOW would they name that many??

[Michele B]

Looks like we'll get a nice rain event here in south Florida, been busy doing interviews for a grad assignment. Will be interesting see on how a potentially stronger 96L could impact the downstream weather pattern.

Hmmm, just got a notice on my weather app for a flooding advisory in Central FL for the next two days. I wondered where that weather was coming from, and then 96 shows up!

[galaxy401]

70/80 now.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Fri Sep 11 2020

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

Shower and thunderstorm activity located over the northwestern and
central Bahamas and the adjacent waters continues to shows signs of
organization. In addition, surface observations indicate that
pressures have fallen over the area since yesterday and, along with
wind and satellite data, suggest that a broad area of low pressure
could be forming between the northwestern Bahamas and South Florida.
This system is forecast to move westward at about 10 mph, and it
could become a tropical depression while it is near South Florida
tonight. But if not, the disturbance is expected to become a
tropical depression while it moves slowly west-northwestward over
the northeastern Gulf of Mexico this weekend and early next week.
Regardless of development, this system is expected to produce
locally heavy rainfall over portions of the Bahamas, South Florida,
and the Florida Keys during the next couple of days, and interests
there, as well as along the northern and eastern Gulf coast, should
monitor its progress.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...80 percent.

[xironman]

Mission status for the Hurricane Hunters have yet to be updated for today. Would be nice if they could schedule a mission for today.

There really isn't much for them to do except burn up some aviation fuel. Its a wave axis, nothing more and we will have ground obs as it moves over Florida.

One of the better waves I have seen

[tomatkins]

I'm so tempted to go all out aggressive on a forecast with this thing. I tend to believe what my eyes are seeing more than what I'm reading from the pro's, but I've been burned enough times to know better. So I'm trying to figure out what's holding model support back? Low level dry air...? not much of an issue. Mid level dry air...? definitely not. shear...? definitely not. In short...a near ideal environment. So what is it....? It's not spinning yet( nothing under the hood)! The models are saying these types of set ups take a quite a bit of time. So the big question is how long will this thing take to spin up? The key is how fast is it moving. In this case and most importantly, it's a (slow) mover. Even now, development probs and intensity estimates are gradually increasing. However, as soon as this thing develops that warm core engine....we should expect intensity estimates to shoot up quite aggressively. http://tropic.ssec.wisc.edu/real-time/m ... anim=html5

I think its probably just a timing thing. HWRF has it strengthening basically from the time it leaves Florida around Naples to when its south of Mobile, then it looks like it might get sheered. But that strengthening period is only 42 hours and its starting as not even a depression. Gets it down to 982 with hurricane force winds though before it weakens.

[jlauderdal]

Mission status for the Hurricane Hunters have yet to be updated for today. Would be nice if they could schedule a mission for today.

There really isn't much for them to do except burn up some aviation fuel. Its a wave axis, nothing more and we will have ground obs as it moves over Florida.

One of the better waves I have seen

https://i.imgur.com/Hb0sY9k.gif

We have seen worse and its clearly developing, I wouldnt send in recon unless it really takes off before "landfall" in sofla. If we have solid data from recon then SOME you manics on the board wont have as much to argue about.. .

[tomatkins]

I'm so tempted to go all out aggressive on a forecast with this thing. I tend to believe what my eyes are seeing more than what I'm reading from the pro's, but I've been burned enough times to know better. So I'm trying to figure out what's holding model support back? Low level dry air...? not much of an issue. Mid level dry air...? definitely not. shear...? definitely not. In short...a near ideal environment. So what is it....? It's not spinning yet( nothing under the hood)! The models are saying these types of set ups take a quite a bit of time. So the big question is how long will this thing take to spin up? The key is how fast is it moving. In this case and most importantly, it's a (slow) mover. Even now, development probs and intensity estimates are gradually increasing. However, as soon as this thing develops that warm core engine....we should expect intensity estimates to shoot up quite aggressively. http://tropic.ssec.wisc.edu/real-time/m ... anim=html5

I think its probably just a timing thing. HWRF has it strengthening basically from the time it leaves Florida around Naples to when its south of Mobile, then it looks like it might get sheered. But that strengthening period is only 42 hours and its starting as not even a depression. Gets it down to 982 with hurricane force winds though before it weakens.

[SFLcane]

Getting more of circular look...still would like to see more obs.

My call is for a 50 mph TS as it moves over the peninsula. We shall see

[Aric Dunn]

Radar is beginning to to rapidly show rotation to the convection near the north tip of Andros..

[edu2703]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Fri Sep 11 2020

Shower and thunderstorm activity located over the northwestern and
central Bahamas and the adjacent waters continues to shows signs of
organization. In addition, surface observations indicate that
pressures have fallen over the area since yesterday and, along with
wind and satellite data, suggest that a broad area of low pressure
could be forming between the northwestern Bahamas and South Florida.
This system is forecast to move westward at about 10 mph, and it
could become a tropical depression while it is near South Florida
tonight. But if not, the disturbance is expected to become a
tropical depression while it moves slowly west-northwestward over
the northeastern Gulf of Mexico this weekend and early next week.
Regardless of development, this system is expected to produce
locally heavy rainfall over portions of the Bahamas, South Florida,
and the Florida Keys during the next couple of days, and interests
there, as well as along the northern and eastern Gulf coast, should
monitor its progress.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...80 percent.

[jlauderdal]

Getting more of circular look...still would like to see more obs.

My call is for a 50 mph TS as it moves over the peninsula. We shall see

Well that's aggressive, a slow down would help you out big time

[sunnyday]

South Fl Mets say nothing from 96 L in this area. This should go through the Straits on the way to the Gulf where it might become a depression or tropical storm. So they say...