ATL: Ex INVEST 92L - Discussion

[abajan]

...
http://manati.star.nesdis.noaa.gov/asca ... Bds100.png

Probably off-topic but there appears to be another LOW which ASCAT caught in that image (on the far right, near 45W).

[SouthDadeFish]

But that upper-tropospheric trough off to its NW is also moving west as can be seen on WV loop imagery plus the GFS shows the shear remaining just to the west of this wave as the wave traverses west through the Caribbean. I can only think that the GFS just thinks there is enough dry and stable air to keep this from developing.

It is indeed moving off to the west, but I made my earlier claim based off the SHIPS forecast, which shows wind shear increasing to around 20 knots in about 2 days and then in excess of 30 knots in 4-5 days. Of course, if a circulation consolidates on the eastern side of the wave, it may have a chance to slow down instead of following the brisk trade winds and development is possible. That is the only way I see this vigorous wave having a shot at developing other than once it reaches the NW Caribbean/Gulf.

[Rgv20]

Shear is screaming to its west side..

[Hurricane Andrew]

It does have the anticyclone...which should help somewhat. Either way, I suspect development will wait until the W Caribbean,

[cycloneye]

2 PM TWO:

A tropical wave, accompanied by a broad area of low pressure, is
moving across the Lesser Antilles. This wave continues to produce
a large area of showers and thunderstorms and gusty winds.
Significant development of this system appears unlikely while it
moves westward at 15 to 20 mph across the Caribbean Sea during the
next several days. Regardless of whether or not development occurs,
this wave will continue to produce locally heavy rainfall and gusty
winds over portions of the Lesser Antilles through early Monday and
should spread over Puerto Rico and Hispaniola during the next
couple of days.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...low...30 percent

[Gustywind]

Hi my friends i'm safe and dry Bad weather is affecting Guadeloupe since yesterday night. We do not report heavy rains in most of the island but hopefully very moderate for the moment ( 10 to 15 millimeters). Whereas, our Pro Mets also reported strong gusts at la Désirade 91km/h and 100 km/h at Marie-Galante. By the way, seas were rough because of Meteo-France Martinica reported seas averaging 2m50 in Dominica's channel with waves up to 5 meters.
Looks like another big round of showers and tstorms should approach our island this afternoon or evening. I will keep your informed. Be on your guard islanders.
Gustywind

[Gustywind]

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
205 PM EDT SUN SEP 04 2016





An Atlantic Ocean tropical wave is along 58W/59W, from 20N
southward, moving westward 15 to 20 knots. A 1008 mb low
pressure center is along the wave near 14.5N. Convective
precipitation: scattered strong from 12N to 16N between 56W and
60W. Widely scattered moderate to isolated strong elsewhere from
11N to 18N between 55W and 70W, from the Atlantic Ocean into the
Caribbean Sea.

[cycloneye]

18z Best Track:

Location: 15.0°N 60.1°W
Maximum Winds: 30 kt Gusts: N/A
Minimum Central Pressure: 1008 mb
Environmental Pressure: 1011 mb
Radius of Circulation: 120 NM
Radius of Maximum Wind: 70 NM

[gatorcane]

latest IR loop, new convection building what looks like around the possible "LLC."

[northjaxpro]

There is at least a mid level rotation near 15.3 N. 60 W.

[Frank P]

Well if it can survive the forecast shear just ahead of it, then we might have another player in the Caribbean to track... would think it would have a decent chance to make the GOM... if it doesn't run straight into Mexico.. probably 50-50 either way ATM... just my opinion...

[Nimbus]

Still has plenty of inflow and convective outflow even with the shear.
I'm not sure why the models are turning it NW unless they expect development?
If it moves west slowly keeping pace with the ULL the shear will be a little less.
We could have a closed system near Jamaica if all the energy doesn't get sheared N over Hispaniola and Puerto Rico.
Hopefully it gets shredded into a remnant (which sounds more like the official forecast).

[SoupBone]

Barbados is now reporting SW winds. At the moment, there appears to only be a strong surface convergence axis, but with sustained convection a LLC may attempt to form. Regardless, the islands can expect some pretty gusts winds in the squalls associated with 92L. The problem for 92L is that it's approaching a strong shear axis associated with an upper-tropospheric trough off to its NW. Chances are the shear associated with the upper-level trough will prevent TC genesis in the short-term.

This is starting to sound like 99L 2.0.

[gatorcane]

I am seeing wind gusts from 40-43mph in Martinique and St. Lucia. Here is a link to look at the obs yourself:

http://www.srh.noaa.gov/sju/?n=observations01

I see a wind gust up to 55 mph in Dominica earlier (13:00 UTC)

Barbados is still reporting a SW wind.

[Sanibel]

Could be trouble IMO.



Disclaimer: Amateur opinion. Use official sources for tropical weather information.

[TheStormExpert]

Joe B. is on board tweeting about 92L.

 https://twitter.com/bigjoebastardi/status/772531118356697088

[Emmett_Brown]

The 12z GFS shows there is shear ahead of 92L in the Caribbean, but as 92L moves west, it appears the anti cyclone at 200mb moves along with it, and the shear lessens along its path. So, while conditions are not ideal, they don't look as bad as the current shear map might indicate. But, it will have to slow down a little to keep from outrunning the anti cyclone.

[Frank P]

Well its certainly looking pretty healthy on the latest vis sat loops... looks to be tracking off to the wnw atm... if it can avoid the shear monster then this system certainly has the potential to be a player in the coming week! Surprised the NHC has the percentages for development so low... I think it should at least be at 40-50 percent on the 5 day development from what I've seen on the sat shots...

[Kazmit]

I'd say the shear right in front of it should hinder development until it reaches the western Caribbean or the GOM. But certainly looking healthy today.

[blp]

The mid level is slightly east of the low level vort over the islands. The system looks to have slowed down some past 3 hrs which is good. I think the models may have been moving this too quick into the teeth of that shear.