INVEST 99L,East of Windwards

[tailgater]

I'm seeing a system that is trying to organize. No, it's not a TD yet, but what did we think that it going was develop in 24 hrs. I would think that it continue to refire then die off again tomorrow and then refire the next day getting a little better organized each day or at least remain a strong tropical wave.

[cheezyWXguy]

Still not even close to being a depression. It has a lot of work left to do.

Yep, it isn't even a low right now even though it has some decent convection. But plenty of time to develop. 98L will be named first if it does.

Do you have any surface plots? Because I heard Steve Lyons say that it is a low. I know TWC is unreliable, but Steve is the only one I listen to.

P.S. Im not using my normal computer so i dont have an NRL link...can someone post one for me that takes it to the tropical cyclone page?

[Blown Away]

Looks like the center is near 10N/50W moving rapidly W to WSW. If a new center does not form near the convection 99L is done IMO. If it does reform it will be near 11N/49W.

http://www.ssd.noaa.gov/goes/flt/t2/loop-avn.html

[TexWx]

It does appear like it my be trying to form a little closer to that flare up.
http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html

[philnyc]

new center would take some time to form; tus, slowing development

As for the GFS model analysis, it is totally WORTHLESS. Unless there was a change, the GFS does NOT assimilate humidity data. The Barbados sounding showed air far drier than anything suggested by GFS

That's not an ASSIMILATION of any RH that I posted. That is from observations and then used for forecasting. Are you specifically saying that the 700mb RH values from the ARL mapping I posted are WORTHLESS, to quote you? If so, I'll send them an email.

Phil

[skysummit]

[btangy]

This pulsating behavior is very characteristic of tropical disturbances. As convection dies off, you get mesoscale downdrafts that act cool and dry the air at the surface. Anybody that has been in a thunderstorm has undoubtedly experienced a gust front heralding cooler air, and thunderstorms in the tropics are no different. It take a little bit of time for this air to recover making the column favorable for deep convection once again. The key is that convection has to come back quickly enough to prevent the vortex from spinning down. Eventually convection moistens the mid-levels enough that downdrafts lessen and convection can maintain itself near the low level center leading to intensification. Dry mid-levels make downdrafts much more vigorous and widespread suppressing convection and preventing the tropical disturbance from intensifying. Whether that is occurring here is questionable.

[Derek Ortt]

from which obs are you using? The obs from Barbados told something different entirely

[RL3AO]

Well, you can't say there isn't model agreement.

[CrazyC83]

Looks like a system for the Caribbean and Central America or the Yucatan/Mexican Gulf Coast if it develops.

[btangy]

That's not an ASSIMILATION of any RH that I posted. That is from observations and then used for forecasting. Are you specifically saying that the 700mb RH values from the ARL mapping I posted are WORTHLESS, to quote you? If so, I'll send them an email.

I'm assuming the ARL is using the analysis from a global model, most likely the GFS, which goes through an assimilation cycle blending observations taken at the most recent synoptic time with a model first guess (model run 6 hours prior). When there are no observations to assimilate, as over tropical oceans esp. at mid-levels, the model first guess is what you pretty much get even after the assimilation cycle. That's not saying it's totally worthless, but I bet there are some pretty big errors if you were to hypothetically take a sounding and compare it to the GFS analysis at an arbitrary point in the middle of the tropical Atlantic ocean.

[Weatherfreak14]

i dont know yet to early to tell, anything could change, its possible if the low forms more and more north, its possible it could head to SFLA if it develops into anything.

[HurricaneRobert]

Where did it go?

GFDL

[Normandy]

Evening thoughts,
Looking at it now, it definitely appears that the MLC we were tracking earlier has vanished and clearly is no longer the dominant center. The MLC we were tracking is diving SW and dissipating. Convection is firing far to the NE of it, and any focus for development likely will be here.

If the new center forms near this convection, it will have gained some nice lattitude, but despite that its still basically guaranteed to go straight into the Carribean.

[windstorm99]

[PTrackerLA]

Yeah go ahead and forget about the center we watched earlier today, it's done. My eyes will be focused around the new convection for *if something is to come of this. It does appear that this blob has good inflow and i detect slight curvature in the low level clouds on the IR around this blob.

[Blown Away]

There have been alot of classified TD's that have looked much worse than 99L does rate now.

[windstorm99]

000
ABNT20 KNHC 310246
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1030 PM EDT MON JUL 30 2007

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

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON NEWLY-FORMED
TROPICAL DEPRESSION THREE...LOCATED ABOUT 270 MILES NORTH-NORTHWEST
OF BERMUDA.

A WESTWARD-MOVING TROPICAL WAVE LOCATED ABOUT 800 MILES EAST OF THE
SOUTHERN WINDWARD ISLANDS CONTINUES TO GENERATE SHOWERS AND A FEW
THUNDERSTORMS. ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR SOME
DEVELOPMENT OF THIS SYSTEM OVER THE NEXT COUPLE OF DAYS.

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

PUBLIC ADVISORIES ON TROPICAL DEPRESSION THREE ARE ISSUED UNDER WMO
HEADER WTNT33 AND UNDER AWIPS HEADER MIATCPAT3. FORECAST/ADVISORIES
ON TROPICAL DEPRESSION THREE ARE ISSUED UNDER WMO HEADER WTNT23 AND
UNDER AWIPS HEADER MIATCMAT3.


$$
FORECASTER FRANKLIN

[Ivanhater]

Well looks like this will be Dean if it forms...

[Weatherfreak14]

nope, it looks TD3 will be chantal, plus dean sounds worse than chantal.