Invest 99L E of Lesser Antilles,Comments,Sat Pics,Etc #3

[wxmann_91]

Wow, I had no idea. In any way, the disturbance in the bottom image is much more organized.

Good comparison wxman57!

It's very hard to determine organization from a single shot, but I think 99L is much more organized. Convection in the lower shot is rather scattered and there's some going on well away from the disturbance. Since it's a single shot, I can't say whether the updraft of the disturbance is generating any convection. With 99L, all the convection is occuring in the center's updraft - there's nothing whatsoever else going on. It's weak and it's sheared but it's as organized as a TD-level disturbance can be.

At the very least the environment around TD 10 is much better. I think someone here said that outflow boundaries aren't good for TC's, well you can compare. In addition, at least the center isn't separated from the convection.

It is clear that the strong shear is displacing the convection to the south. Bone-dry air in the mid-upper levels just adds to the misery. Only thing keeping this dude alive is the upper level divergence.

[Air Force Met]

IMO opinion this is TD based in satellite representation. Not saying that It will survive and become a TS due to shear but as as far as I'm concerned it's a TD. The question is will shear make it an open wave again later or will it become a bonifided Tropical Depression or Storm.

This is the thing though...there are no west winds. It's a storm-relative circulation. I see no eastward moving clouds. I see some clouds not moving west very fast...but none moving east...which would mean we ahve a closed LLC.

[x-y-no]

Be interesting to see the surface observations when this blows through around midnight

http://weather.noaa.gov/weather/current/TFFR.html

I am looking at the buoy reports and I am not very impressed. I am not sure why they have initialized the models at 1011mbs. I think that is a couple of mb too high. The buoy that was just south of there reported a 1014mb as the wave passed...and it was only about 60 miles away. If there was a 3 mb pressure diff...we would see a definite low level circulation.

Funny thing is the pressure actually went UP as the wave approached.

Which bouy is this?

I was just looking at the French bouy (41100) ant it's has steady ENE winds and pressure is currently falling.

Location is 15.90 N 57.90 W.

The steady wind direction was suggesting to me that the wave hasn't reached there yet - am I off in this thinking?

[Air Force Met]

At the very least the environment around TD 10 is much better. I think someone here said that outflow boundaries aren't good for TC's, well you can compare. In addition, at least the center isn't separated from the convection.

Outflow bounderies aren't good for developing TC's. If you want a TD...you don't want to see them. Here are a few reasons.

1) It means a TSTM has collapsed and there is dry air being pulled down into the lower levels. This will kill future convection for a while.

2) As the outflow boundry works outward...it creates divergence from the sfc...which is not what you want to see in a developing TC. This also works against new convection.

3) It disrupts the sfc flow/inflow that might be getting established....especially any LLC that might be trying to develop.

[Thunder44]

GFDL no longer develop this system.

06
WHXX04 KWBC 311727
CHGQLM
ATTENTION...NATIONAL HURRICANE CENTER

NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR

TROPICAL DEPRESSION INVEST 99L

INITIAL TIME 12Z JUL 31

DISCLAIMER ... THIS INFORMATION IS PROVIDED AS GUIDANCE. IT
REQUIRES INTERPRETATION BY HURRICANE SPECIALISTS AND SHOULD
NOT BE CONSIDERED AS A FINAL PRODUCT. PLEASE SEE THE TPC/NHC
OFFICIAL FORECAST.


FORECAST STORM POSITION

HOUR LATITUDE LONGITUDE HEADING/SPEED(KT)

0 15.2 56.8 300./17.1

STORM DISSIPATED AT 0 HRS AT THE ABOVE PSN.

[wxman57]

Take a look at this comparison image. On the top is 99L. But what's that on the bottom?

http://myweb.cableone.net/nolasue/99Lg.gif

I haven't the foggiest, but I'll guess proto-Katrina since I figure you're trying to make a point.

Good guess! The image at the bottom is one I saved from Katrina on August 17th at 1615Z, five days before it became TD 12 and then Katrina.

And I was trying to make a point. The point is we need to look at the big picture and not focus on small fluctuations in organization from hour to hour. Prior to Katrina, we had 2 Cat 4 hurricanes in the Gulf. Conditions across the Caribbean/Gulf were VERY favorable for intensification (i.e., very low wind shear). So even though Katring-to-be didn't look like much on August 17th, the potential was there for significant development.

Now take a look at the conditions in advance of 99L. There are several strong upper-level lows/trofs, with only small pockets of favorable conditions. The Gulf has been dominated by relatively high wind shear, as is most of the Caribbean. So the potential for significant development in the long run appears to be much lower for 99L

But it just goes to show you that you should never totally write off a system because it looks as disorganized as 99L.

[wxman57]

Hey wxman..where did you get the sat image from?

I "roll my own" images using McIDAS software on our Sonalysts workstations.

[curtadams]

Be interesting to see the surface observations when this blows through around midnight

http://weather.noaa.gov/weather/current/TFFR.html

I am looking at the buoy reports and I am not very impressed. I am not sure why they have initialized the models at 1011mbs. I think that is a couple of mb too high. The buoy that was just south of there reported a 1014mb as the wave passed...and it was only about 60 miles away. If there was a 3 mb pressure diff...we would see a definite low level circulation.

Funny thing is the pressure actually went UP as the wave approached.

Where's that buoy? Looks like 16N 61W to me which puts it far ahead of the wave.

[x-y-no]

I think AFM is talking about bouy 41101.

[Air Force Met]

Which bouy is this?

I was just looking at the French bouy (41100) ant it's has steady ENE winds and pressure is currently falling.

Location is 15.90 N 57.90 W.

The steady wind direction was suggesting to me that the wave hasn't reached there yet - am I off in this thinking?

It's 41101...14.6N 56.2W.

Buoy 41100 is right spack dab where the vort ctr is right now...and it will pass just south of there in the next hour or so. I think the pressure will be just a little lower than the 1014mb it is showing now...maybe 1013mb (maybe)...which means the lowest pressure in the wave is about 1013mb right now...maybe 1012 during the diurnal min (at 4pm) and about 1014mb during the diurnal pressure max.

[x-y-no]

Which bouy is this?

I was just looking at the French bouy (41100) ant it's has steady ENE winds and pressure is currently falling.

Location is 15.90 N 57.90 W.

The steady wind direction was suggesting to me that the wave hasn't reached there yet - am I off in this thinking?

It's 41101...14.6N 56.2W.

Buoy 41100 is right spack dab where the vort ctr is right now...and it will pass just south of there in the next hour or so. I think the pressure will be just a little lower than the 1014mb it is showing now...maybe 1013mb (maybe)...which means the lowest pressure in the wave is about 1013mb right now...maybe 1012 during the diurnal min (at 4pm) and about 1014mb during the diurnal pressure max.

OK, thanks, that's what I thought.

The fact that the wind direction hasn't changed at all at 41100 suggests that the vort max we're looking at may not extend all the way to the surface.

[drezee]

The buoy did report a SSW wind...

[Extremeweatherguy]

I'm sorry, but this thing looks just as good as any TD or even weak TS that I have ever seen. It looks much better organized today, and I am amazed the NHC canceled the recon mission even after calling it "well organized".

I can't wait for the recon to go out tomorrow and finally call this what it is....TD 3.

BTW: I can already anticipate the response I will get from the pro mets.

[txwatcher91]

One thing I have noted is that convection is getting closer and closer to the circulation, which means shear is decreasing.
http://www.ssd.noaa.gov/goes/flt/t1/sloop-vis.html

[MortisFL]

I'm sorry, but this thing looks just as good as any TD or even weak TS that I have ever seen. It looks much better organized today, and I am amazed the NHC canceled the recon mission even after calling it "well organized".

I can't wait for the recon to go out tomorrow and finally call this what it is....TD 3.

BTW: I can already anticipate the response I will get from the pro mets.

Give it up man lol. I'd ajust your eyes to the African coastline. GFS/Canadian has been bullish on activity out there.

[Derek Ortt]

There was no recon, because it is obvious that this is not a TD. No need to waste tax payer dollars on a moderate wave

[storms in NC]

You can see that is is pulling moisture in from the southeast

[wxman57]

Here's a new McIDAS image. No clear LLC, just a few very weak eddies rotating cyclonically around a larger area of low pressure. Buoys suggest the lowest pressure in the area is about 1015 mb.

http://myweb.cableone.net/nolasue/99Lh.gif

[NONAME]

THE TROPICAL WAVE PREVIOUSLY ALONG 55W/56W HAS BEEN REPOSITIONED
TO 60/61W S OF 14N MOVING W NEAR 15 KT. THE SURFACE LOW
ASSOCIATED WITH THIS FEATURE HAS BEEN REMOVED AND ANALYZED AS A
TROF FROM 13N58W TO 18N56W. THIS CHANGE WAS MADE DUE TO LOW/MID
CLOUD MOTIONS AND WIND OBSERVATIONS NEAR THE SOUTHERN LESSER
ANTILLES SUGGESTING THE SOUTHERN PORTION OF THE WAVE HAS BECOME
DETACHED...AND IS MOVING WESTWARD THROUGH THE SE CARIBBEAN
SEA...WITH THE NORTHERN TROF PORTION MOVING MORE WNW. THIS MAY
BE REANALYZED AS A SINGLE/CURVED WAVE IN THE 18Z ANALYSIS BUT
CURRENT DATA SUGGESTS THERE ARE TWO SEPARATE FEATURES. THE
SOUTHERN PORTION OF THE WAVE SEEMS TO BE ENHANCING CONVECTION
OVER NORTHERN SOUTH AMERICA SOUTH OF THE ITCZ...WHERE ISOLATED
SHOWERS AND THUNDERSTORMS LIE FROM 2N TO 8N BETWEEN 59W AND 64W.
SHIP...BUOY...AND CLOUD MOTIONS ABOUT 250NM EAST OF DOMINICA
FROM 14N TO 18N BETWEEN 55W AND 59W STILL SHOW CLEAR CYCLONIC
TURNING. SCATTERED MODERATE CONVECTION HAS DEVELOPED NEAR THE
TROF AXIS FROM 13N TO 17N BETWEEN 55W AND 58W. ALTHOUGH
ENVIRONMENTAL CONDITIONS ARE ONLY MARGINAL FOR TROPICAL CYCLONE
DEVELOPMENT...AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT WILL
BE AVAILABLE TO INVESTIGATE THE SYSTEM THIS AFTERNOON...IF
NECESSARY.

I thought they cancelled all the ones for today?

[Weatherfreak000]

I'm sorry, but this thing looks just as good as any TD or even weak TS that I have ever seen. It looks much better organized today, and I am amazed the NHC canceled the recon mission even after calling it "well organized".

I can't wait for the recon to go out tomorrow and finally call this what it is....TD 3.

BTW: I can already anticipate the response I will get from the pro mets.

Lol, well what it IS, is an open wave. The difference between this and all of those "TD's and TS's you thought looked worse" is they all had a little magical something....you know what that is?


LLC. Period.


I don't mean to call you out, but the facts are here. THIS IS NOT a Tropical Depression.