ATL: INVEST 99L - Discussion

[cycloneye]

NHC has a statement at 8 PM TWO for Ex 99L.

A SMALL AREA OF LOW PRESSURE LOCATED ABOUT 300 MILES EAST OF THE
NORTHERN LEEWARD ISLANDS IS PRODUCING DISORGANIZED SHOWER AND
THUNDERSTORM ACTIVITY. UPPER-LEVEL WINDS ARE NOT FAVORABLE FOR
DEVELOPMENT OF THIS SYSTEM...HOWEVER THIS LOW COULD BRING A BRIEF
PERIOD OF RAINFALL AND GUSTY WINDS TO PORTIONS OF THE NORTHERN
LEEWARD ISLANDS ON WEDNESDAY AS IT MOVES WESTWARD AT 15 TO 20 MPH.
THIS SYSTEM HAS A LOW CHANCE...NEAR 0 PERCENT...OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

[Hylian Auree]

Okay, this is reasonable since it most likely won't develop. Just think it deserves the mention

[Nimbus]

Moving too fast and too much shear to develop now but if it keeps firing convection maybe a chance in 72 hours or so. Probably more likely to degrade to a diminishing naked swirl though.

Katrina didn't look much better than 99L when she was out near the Leewards but there wasn't an east coast trough waiting to tear Katrina apart.

[cycloneye]

They mentioned it because it may bring some squally weather to the Leewards,and by doing that it makes people in the islands aware,not that it will develop.

[tobol.7uno]

There was a huge burst of convection last night and this morning, it has bubbled up again tonight, but not as much.

[Gustywind]

Here is 99L becoming closer to the Leewards...

[wxman57]

99L is back, and it really doesn't look that much weaker than Ophelia. Good LLC, convection displaced east of the center. Certainly looks more impressive than Jose ever did.

[Extratropical94]

I guess we have an invest again:

AL, 99, 2011092112, , BEST, 0, 178N, 606W, 25, 1011, DB, 34, NEQ, 0, 0, 0, 0, 1014, 130, 40, 0, 0, L, 0, , 0, 0, INVEST, S,

[westwind]

99L is currently approaching this weather station in barbuda
http://www.ndbc.noaa.gov/station_page.php?station=bara9
Which should give some indication of the pressure and max winds

[wzrgirl1]

Why is there no model run thread yet?

[Extratropical94]

There is, but it has already been moved to the archive.

viewtopic.php?f=54&t=111921&hilit=

[cycloneye]

This thread has been moved from the archieves forum back to this one.

Code: Select all

WHXX01 KWBC 211251
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS NATIONAL HURRICANE CENTER MIAMI FL
1251 UTC WED SEP 21 2011
 
DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.
 
ATLANTIC OBJECTIVE AIDS FOR
 
DISTURBANCE INVEST (AL992011) 20110921 1200 UTC
 
        ...00 HRS...   ...12 HRS...   ...24 HRS. ..   ...36 HRS...
        110921  1200   110922  0000   110922  1200   110923  0000
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    17.8N  60.6W   18.6N  63.8W   19.3N  67.1W   20.5N  70.1W
BAMD    17.8N  60.6W   18.0N  62.4W   18.2N  64.4W   18.3N  66.4W
BAMM    17.8N  60.6W   18.2N  63.2W   18.7N  65.9W   19.3N  68.4W
LBAR    17.8N  60.6W   18.3N  63.2W   18.6N  66.0W   18.9N  68.8W
SHIP        25KTS          27KTS          29KTS          32KTS
DSHP        25KTS          27KTS          29KTS          32KTS
 
        ...48 HRS...   ...72 HRS...   ...96 HRS. ..   ..120 HRS...
        110923  1200   110924  1200   110925  1200   110926  1200
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    21.4N  72.6W   23.3N  75.7W   24.8N  77.3W   27.3N  77.2W
BAMD    18.2N  68.1W   17.6N  71.1W   17.2N  73.1W   17.4N  74.5W
BAMM    19.7N  70.5W   20.0N  73.8W   19.9N  76.0W   20.1N  76.9W
LBAR    19.2N  71.6W   20.2N  76.0W   21.4N  77.9W   21.9N  76.6W
SHIP        34KTS          38KTS          47KTS          54KTS
DSHP        29KTS          36KTS          31KTS          28KTS
 
         ...INITIAL CONDITIONS...
LATCUR =  17.8N LONCUR =  60.6W DIRCUR = 275DEG SPDCUR =  15KT
LATM12 =  17.7N LONM12 =  57.3W DIRM12 = 272DEG SPDM12 =  15KT
LATM24 =  17.6N LONM24 =  54.3W
WNDCUR =   25KT RMAXWD =   40NM WNDM12 =   25KT
CENPRS = 1011MB OUTPRS = 1014MB OUTRAD =  130NM SDEPTH =   S
RD34NE =    0NM RD34SE =    0NM RD34SW =    0NM RD34NW =   0NM
 


[cycloneye]

There is, but it has already been moved to the archive.

viewtopic.php?f=54&t=111921&hilit=

Is back!

[Extratropical94]

There is, but it has already been moved to the archive.

viewtopic.php?f=54&t=111921&hilit=

Is back!

Thanks Luis.

Convection is completely gone, there's just a naked swirl left.



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[tobol.7uno]

Models...

[tobol.7uno]

Not expected to be a storm...

[tobol.7uno]

Thanks Luis.

Convection is completely gone, there's just a naked swirl left.



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That looks like a low level circulation, this is probably a Tropical Depression.

[Extratropical94]

Thanks Luis.

Convection is completely gone, there's just a naked swirl left.



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That looks like a low level circulation, this is probably a Tropical Depression.

Unfortunately, a low level circulation isn't the only criteria for the classification of a tropical cyclone.
You need convection as well as the spin.

Nevertheless, when looking at the image, the winds in this will probably be just as strong as in a TD.

[tobol.7uno]

There was convection though, it all blew off, I would expect to see more at some point today.

[expat2carib]

It's getting windy out here



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