Upper Level Low 18N 64W just east of PR

[northjaxpro]

Other than Maria, there is a bit of a lull in activity in the ATL basin at the moment. One thing I have noted is the ULL northeast of the Leeward Islands. This ULL has been a persistent feature out there for nearly a full week now. I have also watched this feature as it has traversed westward and it does seem to me that this area may be trying to work itself down to the surface. There has been a bit more convection developing today. Sometimes, these ULLs can make it down to the surface over a period of time. It is worth keeping an eye on just in case this happens. The way this season has gone, nothing would surprise me.

[Hylian Auree]

It's about to dissipate. These usually traverse generally southwest and dissipate near the Caribbean around this time of the year.

[underthwx]

NWS Key West AFD Long-Term:



.LONG TERM (SUNDAY THROUGH THURSDAY)...
RAIN CHANCES SUNDAY AND SUNDAY NIGHT WILL BE KEPT ABOVE ALL
NUMERICAL MODEL OUTPUT STATISTICS AS A TROUGH OF LOW PRESSURE
PROGRESSES WESTWARD THROUGH THE SERVICE AREA. THE MONDAY THROUGH
THURSDAY PORTION OF THE FORECAST WILL BE BASED ON CLIMATOLOGY.


http://www.ssd.noaa.gov/goes/east/tatl/rb-l.jpg
I personally think the ULL won't dissapate any time soon..looks like on the loop the two areas of convection are combining over the warm water....the good people residing in the region do not need any more rain...hopefully..some shear and dry air can dissapate it...

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[underthwx]

Wx Underground:
Western Caribbean. We have a classic setup for September/October tropical development in this region by the end of the week. A strong area of High Pressure will be moving out of Canada and into New England by the end of the week wedging all the way down into Northern Florida this weekend. This normally creates Pressure Falls in the Western Caribbean which can lead to tropical development. The GFS model shows these pressure falls and the NOGAPS model does develop a tropical system down there by Friday/Saturday. Again, nothing down there yet, but it will be an area to watch for later this week.




The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[northjaxpro]

Wx Underground:
Western Caribbean. We have a classic setup for September/October tropical development in this region by the end of the week. A strong area of High Pressure will be moving out of Canada and into New England by the end of the week wedging all the way down into Northern Florida this weekend. This normally creates Pressure Falls in the Western Caribbean which can lead to tropical development. The GFS model shows these pressure falls and the NOGAPS model does develop a tropical system down there by Friday/Saturday. Again, nothing down there yet, but it will be an area to watch for later this week.




The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

I agree with you. It appears that the ULL and a surface trough forecast to develop will interact with each other during the next 72 hours as these features traverse westward during this time frame. I would think by the Monday-Tuesday time frame next week we may see a potential area to watch down into the Western Caribbean as the set-up taking shape will be very favorable for surface pressure falls in that region.


Also, more rain this weekend for Puerto Rico
WFD San Juan, PR late this afternoon:

TUTT LOW ACROSS THE CENTRAL ATLANTIC WILL MOVE WEST
AND APPROACH THE LOCAL AREA FOR THE WEEKEND. PW VALUES DECREASED
AND MAY CONTINUE TO DECREASE UNTIL FRIDAY. A SURFACE TROUGH WILL
MOVE ACROSS THE AREA ON SATURDAY THROUGH SUNDAY.

[Hylian Auree]

It might interact with something at the surface, but I doubt it'll become anything on its own. I agree that the Caribbean needs to watch this though, as any additional precipitation is really superfluous and possibly detrimental : (

[northjaxpro]

In this case, the situation of the ULL feature itself working its way down to the surface is most likely not to happen.

But, it will not dissipate quickly either. The ULL and surface trough looks to interact beginning Saturday over PR and the area will move westward.

[cycloneye]

From 8 PM TWD:

A BROAD UPPER LEVEL CYCLONIC CIRCULATION IS CENTERED NEAR
20N57W. THIS FEATURE IS PROVIDING DIVERGENCE FLOW ALOFT TO THE
SE ENHANCING AN AREA OF SCATTERED MODERATE TO STRONG CONVECTION
FROM 10N-15N BETWEEN 50W-64W.

[Hylian Auree]

Yep, classic ull supporting convection set-up.

[underthwx]

can a member post a sat. loop of the ULL please?

[underthwx]

From 8 PM TWD:

A BROAD UPPER LEVEL CYCLONIC CIRCULATION IS CENTERED NEAR
20N57W. THIS FEATURE IS PROVIDING DIVERGENCE FLOW ALOFT TO THE
SE ENHANCING AN AREA OF SCATTERED MODERATE TO STRONG CONVECTION
FROM 10N-15N BETWEEN 50W-64W.

Cycloneeye..(or any member)...can you provide any info. on the ULL..for example...local weather forecasts on how this ULL will affect your region...surface observations...buoy information..etc....???...looking at the satellite loops from a layman's point of view...I see a system organizing...the convection gaining "the Look" of a Tropical Depression....or.....perhaps a Tropical Storm...


The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[Hylian Auree]

http://www.ssd.noaa.gov/goes/east/carb/flash-wv.html
http://www.ssd.noaa.gov/goes/east/carb/flash-vis.html

[underthwx]

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU SEP 15 2011
CARIBBEAN SEA...
BROAD SURFACE CYCLONIC FLOW BETWEEN 72W-84W IS GENERATING
ISOLATED SHOWERS AND THUNDERSTORMS ACROSS THIS AREA. WITHIN THIS
AREA OF WEAK SCATTERED CONVECTION...MOST OF THE ACTIVITY IS
FOCUSED S OF 15N WHERE THE MONSOON TROUGH IS ANALYZED OVER THE
FAR SW BASIN EXTENDING INLAND ACROSS COSTA RICO...PANAMA...AND
NORTHERN COLOMBIA. WATER VAPOR IMAGERY SHOWS A BROAD UPPER LEVEL
CYCLONIC CIRCULATION NE OF THE LESSER ANTILLES. THIS FEATURE IS
ENHANCING AN AREA OF SCATTERED MODERATE TO STRONG CONVECTION
ENTERING THE SE CARIBBEAN S OF 15N E OF 64W. AS THE SYSTEM
CONTINUES TO MOVE WESTWARD...A SURFACE TROUGH MAY DEVELOP OVER
THE SE AND S CENTRAL CARIBBEAN WATERS DURING THE NEXT 12-24
HOURS. THE REMAINDER OF THE BASIN REMAINS UNDER FAIR WEATHER
CONDITIONS. COMPUTER MODELS SUGGEST THE MONSOON TROUGH OVER THE
SW BASIN WILL LIFT N OVER THE NEXT 24-36...HOURS WITH INCREASING
CONVECTION OVER THIS REGION AND INLAND PORTIONS OF CENTRAL
AMERICA.


http://www.ssd.noaa.gov/goes/east/tatl/rb-l.jpg


The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[CrazyC83]

Has a persistent ULL ever became a storm in itself with a surface circulation?

[floridasun78]

my feeling area south of ull will be area to watch as moving into carribbean

[rainstorm]

Has a persistent ULL ever became a storm in itself with a surface circulation?

it happens on rare occasions.

[floridasun78]

Has a persistent ULL ever became a storm in itself with a surface circulation?

nothing going happen with ull it tropical wave to south of it that need to be watch as go into carribbean

[underthwx]

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI SEP 16 2011

CARIBBEAN SEA...
THE UPPER TROUGH OVER THE E GULF OF MEXICO EXTENDS S TO OVER THE
NW CARIBBEAN N OF 14N W OF 77W WITH ISOLATED SHOWERS OVER THE
AREA S OF 20N W OF 83W. THE LARGE UPPER LOW OVER THE CENTRAL
ATLC EXTENDS S OVER THE E CARIBBEAN E OF 72W WITH ISOLATED
SHOWERS/THUNDERSTORMS ARE FROM 13N-18N BETWEEN 69W-72W. THESE
UPPER TROUGHS ARE NARROWING THE UPPER RIDGE BETWEEN THE TWO
WHILE A SURFACE TROUGH IS BENEATH THE UPPER RIDGE EXTENDING
ALONG 80W FROM 10N-18N GENERATING SCATTERED/HEAVY SHOWERS WITH
SCATTERED/NUMEROUS THUNDERSTORMS COVERING THE CENTRAL CARIBBEAN
FROM COLOMBIA AND PANAMA TO CUBA BETWEEN 73W-83W. THE MONSOON
TROUGH EXTENDS ACROSS THE SW CARIBBEAN FROM COLOMBIA NEAR 9N75W
N OF PANAMA NEAR 10N80W INTO THE E PACIFIC REGION OVER COSTA
RICA NEAR 10N84W. SURFACE RIDGE OVER THE CENTRAL ATLC WILL
EXTEND SW THROUGH MON ALLOWING TRADES TO INCREASE OVER MUCH OF E
CARIBBEAN THEN WEAKEN LATE MON AND TUE AS BROAD LOW PRESSURE
WILL POSSIBLY FORM IN SW CARIBBEAN.



The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[underthwx]

ULL hanging in there...wonder if we'll have an invest today...

[DESTRUCTION5]

ULL hanging in there...wonder if we'll have an invest today...

You know its a sad day at S2k when were rooting ULL's into Canes..lol