ATL: SALLY - Post-Tropical - Discussion

[SFLcane]

I will say, unless looks are deceiving in this case, 96L looks much further S than the 00z Euro showed.

It’s sure putting on a show this morning plenty of convection but I think this is one of those cases were looks can be deceiving. Not much under the hood no LLC.

[gatorcane]

850 mb vorticity is increasing, click to see loop:

http://tropic.ssec.wisc.edu/real-time/a ... _loop.html

[Stormcenter]

I guess you forgot that K storm from 2005.

wxman, speedy healing to you.
I think you are underestimating this system, as are models.

Well, he and his team do get paid to do this.

As for the models, yeah they've done pretty poorly all season, but with only a few days until whatever happens to this system, happens, I just don't see them failing as bad as they do a week or more out. But it is 2020 so who knows...

[Aric Dunn]

Looks like a TD is forming or will soon. Stuff snaps together quickly in prime time. Also looks farther south which could be more problematic down the road with more time over water. More rain for FL. My zone is totally waterlogged now. we certainly made up for the early rainy season screw job on the west coast...

Yeah, there could easily be a small meso vort that will become the center under that deep convection( and MLC) east of Andros and Nassau. already a closed broad wind field so the likelyhood of something quickly developing is increasing given the environemnt.

Too bad the Nassau surface obs is having issues.

[aspen]

I think this should be designated as a potential tropical cyclone at 5pm. It’s looking pretty decent and will be impacting land very soon.

[NDG]

Go check out my post on the Euro ensembles on the model thread.

We should see a better defined surface circulation developing later today into tonight before the MLC tracks over S FL tomorrow, IMO.
Saved 8 hr radar loop from the Bahamas, getting better organized by the hour.

[Do_For_Love]

96L is firing off some good convection. Seems to me like it's moving slowly? I guess that's tough to tell with disorganized systems though.

[jhpigott]

Here are a couple good radar links to track 96l as it tracks thru the Bahamas and S. Florida

https://www.sfwmd.gov/weather-radar/cur ... conditions

http://smartmet.bahamasweather.org.bs/radarcomposite/

[NDG]

I will say, unless looks are deceiving in this case, 96L looks much further S than the 00z Euro showed.

The Euro ensembles are trending southward.

[SFLcane]

With little to no shear and warm waters it would not surprise me if intensifies into a TS right before moving into FL.

[CrazyC83]

With little to no shear and warm waters it would not surprise me if intensifies into a TS right before moving into FL.

If the center is adjusting south, it may even shoot for the Straits?

[SFLcane]

Go check out my post on the Euro ensembles on the model thread.

We should see a better defined surface circulation developing later today into tonight before the MLC tracks over S FL tomorrow, IMO.
Saved 8 hr radar loop from the Bahamas, getting better organized by the hour.

https://i.imgur.com/PCkq4kr.gif

Looks solid!

[Aric Dunn]

I am going with there being a meso vort under that deep convection SSE of Nassau that will eventually become the LLC throughout the day.. under the MLC as well. the radar site is on nassau and we are not looking very far up.

Chances are quickly increasing..

[Cat5James]

Hoping for some solid thunderstorms in Broward this weekend

[SFLcane]

It’s got another 15-18hrs before FL. We shall see

[chaser1]

The only inhibiting condition affecting 96L from developing into a T.D. within the next 24 hours would appear to be..... itself. NDG did a nice job of pointing out potential points of low and mid level development and the bottom line is that overall conditions appear quite favorable; just not "magical". There is no CDO however upper level conditions already seem ripe for development at this time. While there is no model support, Frank did point out the 6Z NAM forecasting a sub 1000mb low west of Key West over the weekend. While the 12Z NAM has since backed off, it still significantly deepens 96L tonight as it moves over extreme S. Florida or Florida Keys. If 96L already had a better defined MLC, I'd be betting on LLC development by late this evening. As good as this system is appearing on Satellite this morning, I just don't think that a low/mid level structure will develop rapidly enough for a T.D. to form prior to reaching extreme S. Florida or the Keys but it could be close. It's broad appearance might truly be the only inhibiting factor there. Bottom line, land interaction just doesn't appear to be much of a factor in the overall scheme of things and a COC could very well begin to develop in spite of any interaction with extreme S. Florida. I could well see Miami-Dade, Broward and Keys getting a dumping of 4-6" of rain over the next couple days. Given over all conditions along with being right at the prime point of an overly proficient hurricane season, i'd frankly be surprised if this were not develop into a tropical storm somewhere in the Central or Northern Gulf. I could easily see a high end T.S. coming out of this.

[HurricaneBelle]

May also strengthen if tracks over everglades - ala Katrina

People always say this, but Katrina weakened over Florida. From the NHC report:

Code: Select all

Surface observations and velocity estimates from the Miami and Key West Doppler radars indicated that Katrina weakened over mainland Monroe County to a tropical storm with maximum sustained winds of 60 knots.

The thing about Katrina is that it only spent 6 hours over land because it moved WSW, so it never got much of a chance to weaken. But it didn't strengthen over land.

[tropicwatch]

Might be getting surface circulation.

[Craters]

I see a weak trof axis between SE FL and Andros island. SFC pressures 1012-1013 mb. System will likely move inland between SE LA and FL panhandle as a wave or TD Sunday/Monday. Possibility of weak TS, though model support for TS is minimal.

Status report: Broke my right radius bone where it connects to my wrist in a bike fall Monday. Surgery yesterday to repair with a titanium plate. Feels better no that the 3 pieces of my radius bone are secured. Hard to type left-handed. No lengthy discussions from me.

Ship north of Andros has incorrect pressure, at least.

http://wxman57.com/images/96La.JPG

Sorry to hear that, Wxman. This has also been the summer for bike accidents; a friend had a painful one, too.

I guess the bright side is that yours didn't happen early in your time off or when you could have used all of that comp time. Mother Nature's taking care of that now...

[weeniepatrol]

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1125 AM EDT Fri Sep 11 2020

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

Special Tropical Weather Outlook issued to update the discussion
and development potential for the area of disturbed weather near
the Bahamas.

Updated: 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 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, crossing
the Bahamas and Florida today and tonight and moving into the
eastern Gulf of Mexico on Saturday. The disturbance could become a
tropical depression while it is near South Florida tonight, but it
is more likely to become a tropical depression while it moves slowly
west-northwestward over the eastern 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...medium...60 percent.
* Formation chance through 5 days...high...70 percent.