ATL: Ex INVEST 92L - Discussion

[GCANE]

Two vorts showing up on COD.
One over the LLC and a stronger one to the west imbedded in the convection.

[stormreader]

The ULL over the west GOM is weakening pretty dramatically and the ULL running thru the Bahamas looks like its beginning to erode as well.

http://tropic.ssec.wisc.edu/real-time/w ... oom=&time=

http://mp1.met.psu.edu/~fxg1/SAT_ATL/atlanimwv.html

Yes. Weakening ULL's. WSW move might bring system toward N fringe of Bay of Campeche. Can't rule out possible development.

[Aric Dunn]

Looking at some of the low level flow. It appears to be being pulled by the large convective burst over the flat western side of cuba.

[GCANE]

The ULL over the west GOM is weakening pretty dramatically and the ULL running thru the Bahamas looks like its beginning to erode as well.

http://tropic.ssec.wisc.edu/real-time/w ... oom=&time=

http://mp1.met.psu.edu/~fxg1/SAT_ATL/atlanimwv.html

Yes. Weakening ULL's. WSW move might bring system toward N fringe of Bay of Campeche. Can't rule out possible development.

Last couple frames looks like its turning almost straight south.

Big change in shear as well.

[Aric Dunn]

low level cloud deck starting to thicken some especially on west side closer to the convection and some near the center. may see some more convection soon.

[GCANE]

low level cloud deck starting to thicken some especially on west side closer to the convection and some near the center. may see some more convection soon.

Plenty of unstable air for it to fire off in.
That shift to the SW gets it headed to a 3500 CAPE ridge

[stormhunter7]

[Bailey1777]

Weird movement....are steering currents set to push this all the way to Mexico?

[cycloneye]

3. A weak area of low pressure located over the extreme southeastern
Gulf of Mexico remains devoid of thunderstorm activity. Upper-level
winds are not favorable for development, and the low is forecast to
weaken while it moves westward to west-southwestward at 5 to 10 mph
into the central Gulf of Mexico during the next day or two.
* Formation chance through 48 hours...low...10 percent
* Formation chance through 5 days...low...10 percent

[stormreader]

Weird movement....are steering currents set to push this all the way to Mexico?

Wouldn't say "all the way to Mexico". But motion could bring it farther south than those due west models had it. Might pass not far north of Yucatan. Also looks to be a slow mover. Only a little model support, but that could change with a slow moving system in the south central GOM in mid Sept.

[Aric Dunn]

radar is interesting and satellite showing a large amount of "popcorn" convection building all over the place especially the southern portion as well as around the center.. looks like we will see some deep convection shortly..

[GCANE]

A lot of mid-level moisture is flowing into the LLC now from the convection firing off to its west.

http://www.ssd.noaa.gov/PS/TROP/floater ... -long.html

Obvioulsy, this will enhance convection around the LLC; but will also reduce the PV anomoly over it and allow it's vort to expanded vertically which spins it up.

[hurricanehunter69]

92L has a well defined surface circulation (per visible). I'm noticing the dry slot is filling in and moistening nicely (per water vapor ). The two ULL's on either side of the invest appear to be weakening as well? Check out the possible wrap around and possible formation of a vigorous cyclonic envelope on Mimic http://tropic.ssec.wisc.edu/real-time/m ... /main.html

[Agua]

This is pretty wild to have a naked swirl that won't develop in the Gulf of Mexico at the peak of the season.

[Steve]

This is pretty wild to have a naked swirl that won't develop in the Gulf of Mexico at the peak of the season.

Lesser resolution NAMs spin the low up more in a few days but put an arc of stretched out moisture along the NC Gulf. 4km spins a 1007/8 low in the middle of the Gulf. CMC keeps a weak low moving west toward S TX. Global also hits S TX. GFS is nada.

[abajan]

Down to 0% / 0%

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT SUN SEP 11 2016

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

... A weak area of low pressure located over the extreme southeastern
Gulf of Mexico continues to remain devoid of thunderstorm activity.
Upper-level winds are not favorable, and development of this system
is not expected. The low is forecast to weaken while it moves
westward to west-southwestward at 5 to 10 mph into the central Gulf
of Mexico during the next day or two.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...low...near 0 percent

Forecaster Kimberlain

[GCANE]

That was a big, unexpected increase in shear.

Looking at GFS 350K PV forecast, mid GOM has about 24 hrs for something to develop.

After that, according to this run, it looks like the whole Atlantic will be shut down for at least a week.

http://tc.met.psu.edu/tcgengifs/GFS/201 ... 350PV.anim

Will monitor future runs to see if something changes.

[GCANE]

Coming up to DMAX and getting a cold-topped flare up.
Still looks like substantial shear.
Last I can see, its feeding off 3500 CAPE air but Theta-E is relatively low at around 350.
Doesn't look too promising unless a real big hot tower can fire off for a long time.

[cycloneye]

A few showers and thunderstorms have re-formed near a weak area of
low pressure located over southeastern Gulf of Mexico. However,
upper-level winds will not be conducive for development of this
system while it moves generally westward across the Gulf of Mexico
during the next few days at 5 to 10 mph.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...low...near 0 percent

[Aric Dunn]

wouldn't fully count the little guy out yet.