ATL: INVEST 90L - Discussion

[Janie2006]

It's in more than a bit of trouble at the moment with the convection being blown off to the south of the "center of circulation", if one cares to call it that. That's not the same as saying 90L won't do anything. After all, I watched Danny become a hurricane not 150 miles from where I'm sitting right now....and it didn't take him long to do it after conditions improved.

"Marginally favourable" is just about right, but a lot of things can happen in 96 hours. A lot of things happen in 24 hours. I still don't think 90L escapes the trough, cos that's one strong cold front for early September. Just my estimation, of course.

[LaBreeze]

Could it be Nadine, daughter of Isaac? Hmmm....

[drudd1]

I for one am hoping for a nice severe weather outbreak for FL when the whole thing comes through.

Why?!!

I feel the same way..Its Hurricane Season , time for action...Although I hope only trees get broken and the oceans get a extra nanoliter of water...

No fun when you cant have the wobble wars and trying to stay awake for the next track updates..

Get back with us if your wish comes true and one of those broken trees lands on top of your home

[northjaxpro]

The ULL over the Bahamas has been really hampering 90L with northerly shear. However, the ULL is finally beginning to weaken and lift out to the northeast today. This should help lessen the shear over 90L and provide a 36-hour window for 90L to better align itself to develop. A significant trough coming southeast out of Canada will probably increase shear again over 90L this weekend, which will probably make this a "lopsided" and sloppy tropical cyclone. The shear will keep the system at bay in terms of further strengthening.

I think 90L will develop into a tropical storm in the 45-50 mph range. The strong early autumn type frontal system will sweep down over the weekend an scoop up 90L/potential Nadine out of the GOM and move it across the Florida peninsula. More heavy rains look likely for much of the peninula, but hopefully the cyclone should move through at a good pace to keep any flooding threats at an absolute minimum.

Also, I think this trough looks rather strong and it should be enough to take whatever becomes of 90L/potential Nadine on out to sea into the Atlantic. I would be surprised if this does not happen.

__________________________

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of this poster. For official information, please refer to the NHC and NWS products.

[jlauderdal]

40 seems conservative, i bet we are up to 80 by bedtime(bedtime is a moving target which allows my prediction an excellent chance of verifying)

Up to 40%

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT WED SEP 5 2012

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON RECENTLY
UPGRADED HURRICANE LESLIE...LOCATED ABOUT 465 MILES SOUTH-SOUTHEAST
OF BERMUDA... AND ON TROPICAL STORM MICHAEL...LOCATED ABOUT 1125
MILES WEST-SOUTHWEST OF THE AZORES.

A LOW PRESSURE SYSTEM IS LOCATED OVER THE EXTREME NORTH-CENTRAL
GULF OF MEXICO...ABOUT 25 MILES SOUTHEAST OF PENSACOLA FLORIDA.
SHOWERS AND THUNDERSTORMS HAVE CONTINUED TO DEVELOP NEAR AND TO
THE SOUTH OF THE CENTER...AND ENVIRONMENTAL CONDITIONS ARE EXPECTED
TO BE AT LEAST MARGINALLY CONDUCIVE FOR SOME GRADUAL DEVELOPMENT
OF THIS DISTURBANCE OVER THE NEXT FEW DAYS. THIS SYSTEM HAS A
MEDIUM CHANCE...40 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS AS IT MOVES SOUTHWARD TO SOUTH-SOUTHWESTWARD AT
5 TO 10 MPH. AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT IS
SCHEDULED TO INVESTIGATE THE SYSTEM THURSDAY AFTERNOON...IF
NECESSARY

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER STEWART

could only get 50, fail

[cycloneye]

Down to 40%

Yes,is going down now.

SHOWER ACTIVITY ASSOCIATED WITH A BROAD AREA OF LOW PRESSURE LOCATED
OVER THE NORTH-CENTRAL GULF OF MEXICO HAS NOT BECOME ANY BETTER
ORGANIZED SINCE YESTERDAY...AND IF THIS TREND CONTINUES...THE
RECONNAISSANCE MISSION SCHEDULED FOR LATER TODAY WILL BE CANCELLED.
THIS WEATHER SYSTEM IS DRIFTING SOUTHWARD AND STILL HAS THE
POTENTIAL FOR SOME DEVELOPMENT DURING THE NEXT DAY OR SO BEFORE
ENVIRONMENTAL CONDITIONS BECOME UNFAVORABLE. THIS SYSTEM HAS A
MEDIUM CHANCE...40 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS.

[northjaxpro]

Yeah, it has about a 36 hour window for development before shear increases again with the approach of the trough. We will see. I thought the ULL would move a bit northeast today which would help reduce shear temporary over 90L , which it has been forecast to do the past couple of days by models, but it is hanging tough. Based on that TWO, it sure looks like NHC is leaning toward scrapping the Recon mission for today. The ULL over the Bahamas has been tenacious in helping impart shear over 90L.

__________________________

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of this poster. For official information, please refer to the NHC and NWS products. Follow us on

[tolakram]

Latest



Live Loops:

http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... umframes=5

http://www.esl.lsu.edu/imagery/atmosphe ... n-gulf/IR/

[Hurricaneman]

It still looks sheared, but there seems to be less shear than yesterday, the circulation center isn't completely exposed like yesterday, I personally think recon will be a go

[Aric Dunn]

IT appears from early morning visible and surface obs that we will likely have a TD later today when recon gets out there. although still sheared the shear is on the decrease.

[rainstorm]

Joe Bastardi ‏@BigJoeBastardi

circulation developing south of New Olreans. 25 kt winds around it. Probably a depression http://www.ssd.noaa.gov/PS/TROP/floater ... short.html …

looks better than yesterday to me. im surprised NHC lowered it.

[jlauderdal]

Joe Bastardi ‏@BigJoeBastardi

circulation developing south of New Olreans. 25 kt winds around it. Probably a depression http://www.ssd.noaa.gov/PS/TROP/floater ... short.html …

looks better than yesterday to me. im surprised NHC lowered it.

the NHC vs JB battle continues..lets see what happens with this system today, its life expectancy isn't very long so it better get going, my 80% prediction from yesterday was trash, in fact we have went backward down to 40%

[WeatherGuesser]

Didn't pull an Ivan entirely as 90L is a secondary low spawned by Isaac, not the main one. That's the reason why it will have a new name if it does get named.

That may be the official position, but not necessarily the popular one.

Convection has been looking meager over the past couple of hours, but looks like some new towers may be getting ready to fire just off the mouth of the Mississippi....

Since they're still dealing with flooding and potential dam failures, I really don't think they need any more storms for quite some time.

[cycloneye]

12z Best Track.

AL, 90, 2012090612, , BEST, 0, 285N, 885W, 25, 1009, LO

[Aric Dunn]

maybe availa did not look at the mess it was yesterday and last night when it was 50% and how much more defined the circ is now lol. the convection is sheared still but its right on the edge of 5 to 10kt.

[drezee]

12z Best Track.

AL, 90, 2012090612, , BEST, 0, 285N, 885W, 25, 1009, LO

Almost the exact position Issac was 9 days ago....

[GCANE]

I think the setup is there for a possible flare-up this afternoon, as was the case when Isaac was approaching the coast.

Currently there is a pool of 5000 CAPE air to the SW of the COC.

http://www.spc.noaa.gov/exper/mesoanaly ... sector=18#

90L is advecting this air into its core.

Latest core temp is at 1C with no boundary-layer inversion.

http://rammb.cira.colostate.edu/product ... 2_TANO.GIF

Air over LA & MS is currently capped, but DPs are running 72F + with clear skies.

Diabatic heating should break the cap early this afternoon.

There are no UL PV anomalies over 90L which allows for good parcel ascent.

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

Once the cap over land breaks, I wouldn't be at all surprised to see some good hot towers fire up.

In fact, it looks like there are some overshooting tops firing off this morning.

http://www.ssd.noaa.gov/PS/TROP/floater ... 0-lalo.jpg

[Hurricanehink]

T numbers are 1.0 this morning, up from "too weak".

[MGC]

Looks to me that the circulation center is SE of the Mouth of the River and there is some convection near the CC.....so, it is getting close to being a depression IMO......MGC

The above is the opinion of MGC and not an official forecast.

[BoudreauxWPB]

It still looks sheared, but there seems to be less shear than yesterday, the circulation center isn't completely exposed like yesterday, I personally think recon will be a go

I read earlier a post on FB from a local news station Met in SW LA. that the recon for today had been cancelled due to lack of any organization?