ATL: INVEST 90L - Discussion

[ozonepete]

Far from dead... This was, and is, a TD, no matter what happens going forward....

[Nimbus]

There is an upper level low near 25N 50W that is providing an outflow channel for this little LLC.

Probably the same source for the forecast shear.

The SAL looks like it may erode 91L from the north and force it to feed off the ITCZ for a while so..

[ozonepete]

There is an upper level low near 25N 50W that is providing an outflow channel for this little LLC.

Probably the same source for the forecast shear.

The SAL looks like it may erode 91L from the north and force it to feed off the ITCZ for a while so..

Yes an upper level low will often give very positive outflow to an approaching tropical cyclone. As far as 91L is concerned, that is a good observation but you need to post it in the 91L thread.

I am still wondering what all of the people who wrote this one off are thinking now.

[ozonepete]

Most of the models are forecasting decreasing shear ahead of this and mid-level moisture is certainly increasing now. Don't know why you would write this off yet. Maybe a couple of days down the road this will have problems but not right now... Just look at it.

[cycloneye]

A small area of low pressure located about 650 miles west of the
Cape Verde Islands is producing disorganized showers and
thunderstorms. Environmental conditions are forecast to remain
unfavorable for significant development during the next several
days while it moves west-northwestward at 10 to 15 mph.
* Formation chance through 48 hours...low...near 10 percent.
* Formation chance through 5 days...low...near 10 percent

[wyq614]

Anyway they now stopped claiming that "development is not anticipated" lol~

[gatorcane]

latest vis loop. Convection did increase some overnight but LLC is exposed (southeast side of convection):

[Gustywind]

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN SEP 07 2014

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 32W/33W FROM 19N
SOUTHWARD. A 1010 MB LOW PRESSURE CENTER IS ALONG THE WAVE NEAR
16N. THE WAVE IS MOVING WESTWARD 15 KNOTS. CONVECTIVE
PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG FROM 15N
TO 18N BETWEEN 33W AND 36W.

[cycloneye]

12z Best Track:

90L INVEST 140907 1200 15.5N 34.9W ATL 25 1010

[Blown Away]

Looks like 91L catches 90L...

[blp]

I don't understand why this is still 10%. It is clear by the visible that is much better organized than 10%. I think they should be focusing on what is going on now and not what the models predict will happen.

[gatorcane]

I think this system might have been a depression yesterday but since last night, it has started to really struggle. Looking at the latest vis loop, all of the convection has now been sheared to the NW leaving a naked swirl off to the SE which has become less defined.

http://rammb.cira.colostate.edu/ramsdis ... display=12

[blp]

The ascat confirms the exposed swirl seen on visible is where the llc is located. Like Gator mentioned looks to be getting more broad and ascat shows it might be opening up.

[USTropics]

Elongated 850mb vorticity:

[TropicalAnalystwx13]

Mid-level relative humidity values are down below 40% now, and wind shear, which was already unfavorable, is increasing. This should not be anything of concern.

[Nimbus]

Made it to 35w before becoming a naked swirl and in 24 hours the surface pressure gradient will be flat.
Since its further north, away from the ITCZ it will be interesting to see if the models bring it back when the mid Atlantic ridge build in?

[AEWspotter]

09L, unofficially "AL06", had a short run, but shear and dry air will tear it apart over the next 24-48 hours.

[cycloneye]

2. Showers and thunderstorms associated with a weak area of low
pressure located about 675 miles west of the Cape Verde Islands
have diminished and become well separated from the low center.
Environmental conditions are forecast to remain unfavorable for
development during the next several days while the system moves
west-northwestward at 10 to 15 mph.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.

[cycloneye]

18z Best Track:

90L INVEST 140907 1800 15.6N 36.2W ATL 20 1010

[Hammy]

Definately not closed but looks a bit better at the low levels than yesterday, surprisingly.