Invest 99L,Central Caribbean,Analysis,Sat Pics,Models Thread

[NFLDART]

ANother wait and see game

[HURAKAN]

[double D]

Is it unusual to have such a wide area of dry air this time of year in the Atlantic?

[BensonTCwatcher]

Might be a different story in the carrib.

This thing has been swirling under dry air for long time now. This being the year of the poof notwithstanding, this looks like it could survive the last of this dry air to me. Good chance of seeing this as our next invest despite the TWO not being bullish on it "at this time"

[BensonTCwatcher]

Dry air is around it but it manages to fire just enough convection to stay alive

http://www.atmos.washington.edu/~ovens/loops/wxloop.cgi?wv_east_enhanced+12

[SouthFloridawx]

This low is one very puzzling for me because it's still alive but, in all this dry air. This certainly has to make one a little concerned because once it moves into the Caribbean it will have fairly light windshear according to the models.

http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... hour=072hr
http://moe.met.fsu.edu/cgi-bin/cmctc2.c ... hour=072hr
http://moe.met.fsu.edu/cgi-bin/nogapstc ... hour=072hr

Providing this shear forecast holds out mainly depends on the strength of the ULL to the north but... it looks like the models weaken it.

I'm thinking we should probably watch this feature closely. Just because it doesn't have a ton of convection right now doesn't mean it won't.

Not looking too bad tonight either... small areas of convection but, not devoid.

[SouthFloridawx]

http://www.ssd.noaa.gov/goes/east/carb/loop-rb.html
Looks like we're seeing some more convection... let's see if it lasts overnight.

[TreasureIslandFLGal]

Looks like anything that forms from this wave or the one behind it will probably end up as fish if they gain any latitude. Based on this right now anyway:

http://www.hpc.ncep.noaa.gov/medr/day7nav_color.html

-looks like the US would be kept safe because of a trough.

Of course, things change and the models never seem to get teh whole story, so let's see where we are at the end of the week next week and reevaluate then.

[WxGuy1]

Looks like anything that forms from this wave or the one behind it will probably end up as fish if they gain any latitude. Based on this right now anyway:

http://www.hpc.ncep.noaa.gov/medr/day7nav_color.html

-looks like the US would be kept safe because of a trough.

Of course, things change and the models never seem to get teh whole story, so let's see where we are at the end of the week next week and reevaluate then.

Treasure,

That's partially possible and partially inconclusive given the data you presented. Many undeveloped waves are shallow, so they are "steered" largely by low-level flow. As cyclones organize and deepen, their steering-level flow increases. In other words, deeper TS and hurricanes are affected by the mean flow in, for example, the 400-650mb layer (just say the midlevels).

The link that you present shows surface features; as such, you may be able to "guestimate" the motion of shallow waves. For deeper, more organized cyclones, however, a surface map will tell you little about the "steering currents". Depending upon the stage of development of the cold front itself, it may or may not be associated with an upper-level trough. For example, a surface cold front may advance slowly or stall even as ridging aloft builds. Oftentimes, this will result in frontolysis (meaning the front "washes out"). Regardless, it's best not to look at surface maps when trying to view the steering flow of tropical cyclones. SOMETIMES cold fronts will be associated with upper-level troughs with westerly-component flow downstream, but that doesn't necessarily have to be the case. If the cold front is weak, for example, it would be possible for heights to build in the post-frontal areas if there is warm-air advection just off the surface (not uncommon for "old" shallow cold fronts, before it retreats back northward).

In this case, there does appear as though an upper-level trough will progress through the eastern US during that time-frame, but the presence of a cold front on that graphic doesn't mean that that will always be the case. The deep upper-level trough appears as though it'll stay over the eastern US from Tuesday through the end of next weekend. Another deep trough looks poised to dig across the central US and into the eastern US after next weekend, but the usual "it's a long ways out" disclaimer applies. It does look like it'll be extremely difficult to get an east-coast landfall with any possible cyclone through the next 10 days.

LOL This would be a better mini-lesson if the cold front wasn't going to be associated with a deep eastern US trough. But, that may save you some headaches down the road when you wonder why a tropical cyclone continues to head right for a cold front drawn on that HPC map.

[Meso]

000
ABNT20 KNHC 020928
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
530 AM EDT SAT SEP 2 2006

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

A SMALL AREA OF LOW PRESSURE LOCATED JUST EAST OF THE LESSER
ANTILLES IS MOVING WESTWARD ABOUT 15 MPH. ASSOCIATED SHOWERS AND
THUNDERSTORMS HAVE INCREASED AND WILL SPREAD OVER THE LESSER
ANTILLES TODAY. HOWEVER...UPPER-LEVEL WINDS ARE UNFAVORABLE FOR
SIGNIFICANT DEVELOPMENT.

[SouthFloridawx]

GFS is forecasting more favorable upper level winds.
http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_030m.gif
Upper Level High over the area should help ventilate the convection.

[O Town]

000
ABNT20 KNHC 020928
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
530 AM EDT SAT SEP 2 2006

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

THE HYDROMETEOROLOGICAL PREDICTION CENTER IN WASHINGTON DC IS
ISSUING ADVISORIES ON THE REMNANTS OF ERNESTO...CENTERED OVER
EASTERN VIRGINIA.

A TROPICAL WAVE LOCATED ABOUT HALFWAY BETWEEN AFRICA AND THE LESSER
ANTILLES IS MOVING WESTWARD AT 10 MPH. SHOWER AND THUNDERSTORM
ACTIVITY HAS INCREASED OVERNIGHT AND GRADUAL DEVELOPMENT OF
THIS SYSTEM IS POSSIBLE OVER THE NEXT DAY OR TWO.

A SMALL AREA OF LOW PRESSURE LOCATED JUST EAST OF THE LESSER
ANTILLES IS MOVING WESTWARD ABOUT 15 MPH. ASSOCIATED SHOWERS AND
THUNDERSTORMS HAVE INCREASED AND WILL SPREAD OVER THE LESSER
ANTILLES TODAY. HOWEVER...UPPER-LEVEL WINDS ARE UNFAVORABLE FOR
SIGNIFICANT DEVELOPMENT.

ELSEWHERE...TROPICAL STORM FORMATION IS NOT EXPECTED THROUGH
SUNDAY.

$$
FORECASTER BROWN/KNABB

[tailgater]

From 8:05 TWD
TROPICAL WAVE IS ALONG 58W/59W S OF 19N WITH A 1009 MB LOW ALONG
THE WAVE NEAR 15N MOVING W 15 KT. THE WELL DEFINED LOW LEVEL
SWIRL HAS FILLED IN WITH CONVECTION OVERNIGHT AND IS MOVING
ACROSS THE LESSER ANTILLES. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS WITHIN 90/120 NM OF LINE 13.5N57W-16.5N62W

[DESTRUCTION5]

Its got a low and Convection...Only thing it don't have is a clean enviroment in front of it....Other wise id say this is a go...

[HURAKAN]

This system should be 99L already.

[tailgater]

This little Low has been right smack in the middle of alot of dry for the last 3 days( if not more). Models weaken it over the next couple of days though, probably our buddy shear.

I know Rock and SouthFloridawx don't think so, but I think the shear will kill off this one also.
http://www.ssd.noaa.gov/goes/east/carb/loop-wv.html

[SouthFloridawx]

http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... =Animation
Favorable Conditions for this low in the very near future.



http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_048l.gif

[HenkL]

It's 99L.INVEST now on the nrlmry site.

[cycloneye]

http://www.nrlmry.navy.mil/tc_pages/tc_home.html

[SouthFloridawx]

Ok I see someone changed it.
I think Upper Level winds will be more favorable soon for this one. All the models seem to think so also.