ATL: INVEST 99L - Discussion

[MGC]

40KTS....enough convection near the center for an upgrade?....I think so...MGC

[cycloneye]

Well if it does develop into a storm and the September low being discussed on the board is upgraded post-seasonal, would the unnamed storm also count towards the poll?

Only named storms count for the poll, so if Tammy forms from this,#49 StormingB81 would be the solo winner with 19/7/3.

[Dean_175]

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
700 PM EST MON NOV 21 2011

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

1. AN AREA OF LOW PRESSURE LOCATED ABOUT 900 MILES EAST OF BERMUDA
CONTINUES TO PRODUCE GALE-FORCE WINDS. WHILE THIS SYSTEM HAS
CHANGED LITTLE IN ORGANIZATION DURING THE PAST FEW HOURS AND STILL
HAS SOME FRONTAL CHARACTERISTICS...IT IS FORECAST TO INTENSIFY
DURING THE NEXT COUPLE OF DAYS AS EITHER A FRONTAL LOW OR A
SUBTROPICAL CYCLONE. THIS SYSTEM HAS A HIGH CHANCE...60 PERCENT...
OF BECOMING A SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT
MOVES NORTH-NORTHEASTWARD TO NORTHEASTWARD AT 10 TO 15 MPH.
ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS
FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS
HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

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

$$
FORECASTER BRENNAN/BERG
NNNN

[Dean_175]

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
700 PM EST MON NOV 21 2011

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

1. AN AREA OF LOW PRESSURE LOCATED ABOUT 900 MILES EAST OF BERMUDA
CONTINUES TO PRODUCE GALE-FORCE WINDS. WHILE THIS SYSTEM HAS
CHANGED LITTLE IN ORGANIZATION DURING THE PAST FEW HOURS AND STILL
HAS SOME FRONTAL CHARACTERISTICS...IT IS FORECAST TO INTENSIFY
DURING THE NEXT COUPLE OF DAYS AS EITHER A FRONTAL LOW OR A
SUBTROPICAL CYCLONE. THIS SYSTEM HAS A HIGH CHANCE...60 PERCENT...
OF BECOMING A SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT
MOVES NORTH-NORTHEASTWARD TO NORTHEASTWARD AT 10 TO 15 MPH.
ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS
FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS
HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

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

$$
FORECASTER BRENNAN/BERG
NNNN

How is it frontal? I don't see an associated cold/warm front on an analysis chart? Can someone please answer this

[bg1]

1. SURFACE OBSERVATIONS NEAR THE LOW PRESSURE AREA LOCATED ABOUT
1000 MILES EAST-SOUTHEAST OF BERMUDA INDICATES THAT THIS SYSTEM
CONTINUES TO OBTAIN FRONTAL CHARACTERISTICS. THE LOW IS LIKELY TO
STRENGTHEN AS AN EXTRATROPICAL CYCLONE AND CONTINUE PRODUCING GALE
FORCE WINDS AS IT MOVES NORTHEASTWARD DURING THE NEXT COUPLE OF
DAYS. THIS SYSTEM HAS A LOW CHANCE...10 PERCENT...OF BECOMING A
SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS. ADDITIONAL
INFORMATION ON THIS LOW CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED
BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND
WMO HEADER FZNT01 KWBC.

There's always next year...

[ozonepete]

I think they're writing it off too soon. The circulation appears to be separating from the front and is still over marginally favorable SSTs. A circular area of convection is once again building over the LLC. This one has tenacity.
If there was ever a theme to this season it's had two parts:
1. Most systems that developed didn't become very strong.
2. A lot of disturbances this year were not expected to develop into named storms, but did anyway.

This one is following both rules. I think this will get named. If not in the next 2 days, then after the season is over.

[ozonepete]

BTW, notice how the low (where that ball of convection is) is behind the front. That would be really odd for such a low to survive and become tropical or subtropical. But that's the kind of season it's been. Very unusual development scenarios. For this to survive it has to go further east than north for now and stay separate fom the front which should dissipate.

(Notice it's developing some outflow cirrus, a more tropical characteristic.)

[StormingB81]

Question because I have not seen this before. Not to say it hasn;t happend I just haven't seen it before. On the NRL site it shows that there is a chance of developement. Why does it show it as a tropical storm on it? Thanks

[ozonepete]

I think you're talking about this forecast image they put out, right? It's actually a forecast for 18Z on November 21st, which was Monday afternoon. I think that's an old forecast and they have just not updated it since the NHC dropped the possibility from 60% to 10%.

[ozonepete]

Really unusual, hybrid kind of system. It looks like the low is maintaining a circular, very tropical like configuration while the front is moving out ahead of it. While I wouldn't think it should develop given the ongoing conditions, I'm not sure, and am very curious how this will pan out. It certainly looks more tropical than it did earlier today.

[Epsilon_Fan]

how is this not on the Tropical outlook still? Just look at the recent loop, the convection is around the center and the circulation is still tight. Certainly doesn't look like a typical extratropical low yet.

[Chickenzilla]

I think it is at least a subtropical depression.

[cycloneye]

SSD dvorak is still releasing numbers as ST.

23/1145 UTC 31.9N 39.7W ST1.5 99L

[cycloneye]

NHC mentions it again.

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
700 PM EST WED NOV 23 2011

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

SATELLITE DATA THIS EVENING INDICATE THAT SHOWER ACTIVITY HAS
INCREASED NEAR THE CENTER OF A LOW PRESSURE AREA CENTERED ABOUT
500 MILES SOUTHWEST OF THE AZORES...AND THAT STRONG WINDS ASSOCIATED
WITH THE LOW HAVE BECOME MORE CONCENTRATED NEAR THE CENTER.
HOWEVER...THE LOW HAS WELL-DEFINED FRONTS...AND ENVIRONMENTAL
CONDITIONS ARE NOT CURRENTLY FAVORABLE FOR SUBTROPICAL CYCLONE
DEVELOPMENT. THIS SYSTEM HAS A LOW CHANCE...NEAR 0 PERCENT...OF
BECOMING A SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS.

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

$$
FORECASTER BEVEN

[Epsilon_Fan]

well, it looks frontal/extratropical now, but 24 hours ago it looked hybrid or subtropical