ATL: INVEST (97L)

[Weatherboy1]

shear still is high in the vicinity, but sure does appear to be lessening, no?

http://cimss.ssec.wisc.edu/tropic2/real ... oom=&time=

[HURAKAN]

Maybe this is why the convection is so strong near the MLC.

[Ed Mahmoud]

It's seems that is very possible that 97L or at least some energy from it will develop off the US East Coast. CMC, GFS, NOGAPS and ECMWF are in agreement though I don't buy what CMC is predicting, conditions will be only marginal to support development, and a subtropical cyclone is more likely. This is just and unofficial opinion By the way, do you think that 97-L and the Bahamas disturbance could have some interaction and develop?

The Canadian combines and develops the two separate areas of low level vorticity depicted.

Anyway, wide area satellite water vapor loop. East of the big trough, it appears the trough is inducing a sympathetic ridge, centered over the extreme Eastern Bahamas.


I don't automatically accept the Canadian, nor do we know how successful they were in tamping down its tendency to feed back too much, but it might be in the right ball park.

Or it might not be.

It is only July.

[floridasun78]

i notice that nhc change their wording 000
ABNT20 KNHC 210521
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT TUE JUL 21 2009

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

A TROPICAL WAVE ENTERING THE EASTERN CARIBBEAN SEA IS PRODUCING
DISORGANIZED SHOWERS AND THUNDERSTORMS. UPPER-LEVEL WINDS ARE
EXPECTED TO REMAIN UNFAVORABLE FOR DEVELOPMENT OF THIS SYSTEM FOR
THE NEXT COUPLE OF DAYS. that from 2am here the today 2pm 000
ABNT20 KNHC 211804
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT TUE JUL 21 2009

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

A TROPICAL WAVE OVER THE EASTERN CARIBBEAN SEA IS PRODUCING AN AREA
OF CONCENTRATED SHOWERS AND THUNDERSTORMS. HOWEVER...UPPER-
LEVEL WINDS REMAIN UNFAVORABLE FOR DEVELOPMENT OF THIS SYSTEM AT
THIS TIME. maybe their see shear droping in area of bahamas

[HURAKAN]

Even if conditions improve, the system is about to be disrupted by Hispaniola.

[cycloneye]

You can follow the circulation at the San Juan long range radar.It looks like its moving more slowly west.

http://radar.weather.gov/radar.php?rid= ... 1&loop=yes

Sidebar note=I am writting this under a Severe Thunderstorm.Internet has gone on and off this afternoon.I am posting what is going on at Weather Attic.

[KWT]

I doubt land is going to make a massive amount of difference to a wave that is disorganised Hurakan, may help to split the wave but given the wave is not exactly well organised it looks like its not gonig to make much of a difference IMO.

[lrak]

That little burst has seperated from the large disturbance and the last visible satellite loop shows some LL inflow on the west side of the burst? Anyone see this?

[weatherwindow]

per the AFD nws/mia...................................................................................................THE SECOND TROPICAL WAVE OVER HISPANIOLA SHOULD ALSO MOVE MORE
NORTHWEST AND NORTHWARD TONIGHT INTO THURSDAY INTO THE BAHAMA
ISLANDS...AS A POSSIBLE WEAK LOW COULD DEVELOP WITH THE SECOND
TROPICAL WAVE. THIS SHOULD KEEP SOUTH FLORIDA IN THE DRIER AIR
MASS ASSOCIATED WITH THE SECOND TROPICAL WAVE FROM WEDNESDAY NIGHT
INTO THURSDAY NIGHT. SO HAVE LOWER THE POPS TO CHANCE CAT FOR
WEDNESDAY...AND THEN DOWN TO SLIGHT CHANCE EXCEPT CHANCE CAT
AROUND THE LAKE OKEECHOBEE AREA ON THURSDAY.

[cycloneye]

Interesting to say the least.

[lester]

Interesting to say the least.

whoa that doesn't look good O_O

(to my untrained eyes at least)

[Ed Mahmoud]

Staring very closely at my NASA cake mix home-made SUPER CLOSE-UP HIGH RES VISIBLE FLOATER, and I can't see any West to East component of low cloud motion to the Southwest or South of the big blob.

[poof121]

Too bad there are no obs south of the "center". There is a SE one where it should be, but as we know SE doesn't really mean anything.

Code: Select all

ID      T1 TIME    LAT     LON DIST HDG WDIR  WSPD   GST  WVHT   DPD   APD MWD   PRES  PTDY  ATMP  WTMP  DEWP   VIS  TCC  TIDE  S1HT  S1PD  S1DIR  S2HT  S2PD  S2DIR   Ice   Sea      SwH      SwP     SwD     WWH    WWP    WWD      STEEPNESS
           (GMT)                 nm  °T   °T   kts   kts    ft   sec   sec  °T     in    in    °F    °F    °F   nmi  8th    ft    ft   sec     °T    ft   sec     °T   Acc   Ice       ft      sec              ft    sec     
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
LPRP4    O 1950  17.94  -67.05   78  44  120  19.0     -     -     -     -   -      -     -     -     -     -     -    -     -     -     -      -     -     -      -  ---- -----        -       -       -       -      -      -              -
LPRP4    O 1940  17.94  -67.05   78  44  130  22.0     -     -     -     -   -      -     -     -     -     -     -    -     -     -     -      -     -     -      -  ---- -----        -       -       -       -      -      -              -
LPRP4    O 1930  17.94  -67.05   78  44  130  22.0     -     -     -     -   -      -     -     -     -     -     -    -     -     -     -      -     -     -      -  ---- -----        -       -       -       -      -      -              -
LPRP4    O 1920  17.94  -67.05   78  44  130  20.0     -     -     -     -   -      -     -     -     -     -     -    -     -     -     -      -     -     -      -  ---- -----        -       -       -       -      -      -              -

[lrak]

Staring very closely at my NASA cake mix home-made SUPER CLOSE-UP HIGH RES VISIBLE FLOATER, and I can't see any West to East component of low cloud motion to the Southwest or South of the big blob.

I'm good then, I always see SPIN....SURF...LOL

[poof121]

No LLC yet, according to this buoy... ESE winds south of the "center".

http://www.ndbc.noaa.gov/station_page.php?station=42059

[cycloneye]

Another view of long range radar.

[poof121]

Question for the Pro Mets, or anyone who might know... Can orographic effects cause cyclogenesis?

[wxman57]

Here's a recent surface analysis with visible satellite overlay. I've identified the very weak (and weakening) MLC with the red crosshairs. As you can see, absolutely nothing at the surface except straight ESE-SE winds at 15 kts through the disturbance. Wind shear in its path remains 30-40 kts, and that won't really let up as it passes the Bahamas and begins interacting with the strong SW winds associated with the frontal boundary. It already looks like the moisture is being stretched to the northwest up the approaching upper-level trof if you look at a WV or MIMIC TPW loop. Development chances (tropical) remain very low, probably less than 5%. It could form a wave on the cold front in a few days, maybe a weak frontal low, but I think that's about it for 97L

[lrak]

Here's a recent surface analysis with visible satellite overlay. I've identified the very weak (and weakening) MLC with the red crosshairs. As you can see, absolutely nothing at the surface except straight ESE-SE winds at 15 kts through the disturbance. Wind shear in its path remains 30-40 kts, and that won't really let up as it passes the Bahamas and begins interacting with the strong SW winds associated with the frontal boundary. It already looks like the moisture is being stretched to the northwest up the approaching upper-level trof if you look at a WV or MIMIC TPW loop. Development chances (tropical) remain very low, probably less than 5%. It could form a wave on the cold front in a few days, maybe a weak frontal low, but I think that's about it for 97L

[Derek Ortt]

there may be enough QG forcing for more than a weak frontal wave