SE Bahamas (Is Invest 91L)

['CaneFreak]

I know we have a bunch of model huggers on here but I see an area of thunderstorms developing near the SE Bahamas sitting in 5 to 10 knots of shear, well removed from the upper trough but is still getting plenty of UL divergence, sitting underneath the Bermuda ridge (providing low level convergence), and already has a weak 850 circulation over the Bahamas. Sure, it doesn't have model support but it is worth discussing right? This moisture would likely get drawn into the trough to bring more rain to the East Coast.

[rainstorm]

http://www.atmos.washington.edu/cgi-bin/latest.cgi?ir-e

looks far more interesting than ophelia.

[northjaxpro]

Good observation CaneFreak. The area of disturbed weather near the SE Bahamas has continued to look better through the day into this early evening. I'll be interested to see if the TWD from NHC will reference that area in about an hour from now.

[wxman57]

There is a small area of lower shear there, but shear is on the increase as an upper low develops to its southeast and the trof deepens to its immediate west. Just a narrow area of favorable winds for a short time. Should be zipping up the front this weekend.

[northjaxpro]

There is a small area of lower shear there, but shear is on the increase as an upper low develops to its southeast and the trof deepens to its immediate west. Just a narrow area of favorable winds for a short time. Should be zipping up the front this weekend.

Thanks wxman57 for your analysis. So the hostile upper level shear will be commencing soon over that area to effectively keep this system from potentially developing into anything. Plus, as you mentioned, the trough will eventually scoop it up out to sea during the weekend.

[NDG]

Surface pressures are high and showing no signs of lowering much.
Highest vorticity is closer to the mid levels of the atmosphere but has been increasing slightly during the day at H85.
If it was to stick around for a while maybe vorticity would be working its way down but with the approaching trough it will be picked up quickly like mentioned above.

[GCANE]

Been watching this for the last 24 hrs.

Anti-cyclone has just popped up.

Surface pressure is still a bit high and generally steady and rain-rate has been low in the convection.

If rain-rate picks up, I think we may have a surprise.

I am wondering if it spins up closer to the straights that it may miss the scoop and have a chance to ramp up.

['CaneFreak]

Been watching this for the last 24 hrs.

Anti-cyclone has just popped up.

Surface pressure is still a bit high and generally steady and rain-rate has been low in the convection.

If rain-rate picks up, I think we may have a surprise.

I am wondering if it spins up closer to the straights that it may miss the scoop and have a chance to ramp up.

I agree with the bolded portion but not so much with the underlined portion. I think it just needs one good burst of convection to get that circulation down to the surface...but as far as track...it will likely get slung like a rock in a sling shot up the east coast...not buying this northeast motion offshore nonsense...not with the main upper low over the OV...but it certainly won't miss the trough...

[GCANE]

Current steering

[GCANE]

500mb cut-off low seems to retro a bit over the Great Lakes

http://mag.ncep.noaa.gov/NCOMAGWEB/appcontroller?prevPage=Model&MainPage=index&image=&page=Param&cycle=09%2F23%2F2011+12UTC&rname=UPPER+AIR+PARMS&pname=500_vort_ht&pdesc=&model=GFS&area=ATLANTIC&cat=MODEL+GUIDANCE&fcast=Loop+All&areaDesc=Atlantic+region&prevArea=ATLANTIC&currKey=model&returnToModel=&imageSize=M

[GCANE]

Rain rate is picking up to moderate levels and 200mb has quickly shaped up.

JB is scratching his head and so am I.

http://twitter.com/#!/BigJoeBastardi
"Still dont understand why what is near Bahamas is totally ignored. More tstorms than Ophelia http://pic.twitter.com/9gg8f8CX'

[AJC3]

Rain rate is picking up to moderate levels and 200mb has quickly shaped up.

JB is scratching his head and so am I.

http://twitter.com/#!/BigJoeBastardi
"Still dont understand why what is near Bahamas is totally ignored. More tstorms than Ophelia http://pic.twitter.com/9gg8f8CX'

There's a weak inverted trough in that area, and perhaps a little bit more sense of weak cyclonic turning in the METARs and cloud motion vectors compared to yesterday, however pressure from a ship (J8PE4) right in the center of the convection was 1016MB and pressures are actually several millibars lower well to the NW out ahead of this feature. For better or worse, (and right or wrong) JB generally takes a contrarian stance versus NHC and NOAA.

[NDG]

Surface vorticity has formed, IMO, looks broad at the time, pressure in the Bahams are still high around 1012mb but a couple of mb lower than 24 hrs ago.

[cycloneye]

10%

DISORGANIZED SHOWERS AND THUNDERSTORMS OVER PORTIONS OF THE BAHAMAS
ARE ASSOCIATED WITH A SURFACE TROUGH OF LOW PRESSURE. ALTHOUGH
SURFACE PRESSURES IN THE AREA HAVE BEEN FALLING...DEVELOPMENT OF
THIS SYSTEM...IF ANY...WILL BE SLOW TO OCCUR AS IT MOVES GENERALLY
NORTHWARD AT 10 TO 15 MPH. THIS SYSTEM HAS A LOW CHANCE...10
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

[westwind]

looks to be organising quite rapidly though it could be related to the MLC not an LLC. The vorticity should have reached to the surface or at least close to the surface. assuming the LLC forms soon 90L should have the oppotunity to strengthen fairly quickly into a storm, so long as the current highly favorable conditions (low shear, warm water and improving outflow due to the anti-cyclone forming above the center.

[GCANE]

Pressure dropping

http://64.19.142.11/www.ndbc.noaa.gov/p ... _label=EDT

[NDG]

looks to be organising quite rapidly though it could be related to the MLC not an LLC. The vorticity should have reached to the surface or at least close to the surface. assuming the LLC forms soon 90L should have the oppotunity to strengthen fairly quickly into a storm, so long as the current highly favorable conditions (low shear, warm water and improving outflow due to the anti-cyclone forming above the center.

It would be 91L, they have assigned 90L to the tropical wave near the C.V. Islands earlier today.

[Dean4Storms]

Getting interesting

[bexar]

how are the models doing on this thing?

[wx4me]

2. DISORGANIZED SHOWERS AND THUNDERSTORMS OVER PORTIONS OF THE BAHAMAS
ARE ASSOCIATED WITH A SURFACE TROUGH OF LOW PRESSURE. ALTHOUGH
SURFACE PRESSURES IN THE AREA HAVE BEEN FALLING...DEVELOPMENT OF
THIS SYSTEM...IF ANY...WILL BE SLOW TO OCCUR AS IT MOVES GENERALLY
NORTHWARD AT 10 TO 15 MPH. THIS SYSTEM HAS A LOW CHANCE...10
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

So I woud assume if this developes or not, it would steer of to the N.E. Correct?