ATL: EX-Tropical Depression FIVE - Discussion

[Ivanhater]

JB's take

MONDAY 6PM
Southeast Gulf low looking better.

A look at the data buoys show pressure are falling and winds are increasing. Polaski Shoal has had WEST winds over 20 kts

p://www.ndbc.noaa.gov/show_plot.php?sta ... e_diff=-4& time_label=EDT


this is an impressive wind for so far south into what is normally a component from the southeast. My take is the hatch-it people will go to the red hatch soon on this.

[KWT]

I don't see the ULL going due west though, I see it heading NW at the moment...I mean that may not make a huge difference I'm not sure just yet...

That dry slot maybe an issue, but with an old frontal boundary lurking, there is likely going to remain enough instablity to allow some convection on the southern side of the circulation.

[lrak]

http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... mframes=15

Games on...IMO. Maybe we'll get a good east swell if it stays at that latitude for a while.

[Aric Dunn]

I don't see the ULL going due west though, I see it heading NW at the moment...I mean that may not make a huge difference I'm not sure just yet...

That dry slot maybe an issue, but with an old frontal boundary lurking, there is likely going to remain enough instablity to allow some convection on the southern side of the circulation.

yeah NW motion it is..

[ronjon]

The center seems to be tightening up just west of Naples tonight.

http://www.rap.ucar.edu/weather/satellite/displaySat.php?region=TPA&itype=vis&size=large&endDate=20100612&endTime=-1&duration=3

[cycloneye]

Up to 40%

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT MON AUG 9 2010

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

SHOWER AND THUNDERSTORM ACTIVITY ASSOCIATED WITH A LOW PRESSURE AREA
LOCATED ABOUT 875 MILES EAST-NORTHEAST OF THE LEEWARDS ISLANDS
REMAINS LIMITED AND DISORGANIZED. ENVIRONMENTAL CONDITIONS ARE
EXPECTED TO BE MARGINALLY CONDUCIVE FOR DEVELOPMENT OF THIS
DISTURBANCE...AND ANY SIGNIFICANT ORGANIZATION OF THE THUNDERSTORMS
COULD RESULT IN THE FORMATION OF A TROPICAL CYCLONE. THE LOW IS
MOVING WEST-NORTHWESTWARD AT 10 TO 15 MPH AND IS EXPECTED TO TURN
NORTHWESTWARD AND NORTHWARD DURING THE NEXT COUPLE OF DAYS. THERE
IS A HIGH CHANCE...70 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HOURS.

A WEAK LOW PRESSURE AREA OVER THE SOUTHEASTERN GULF OF MEXICO...JUST
OFFSHORE OF THE SOUTHWEST FLORIDA COAST...CONTINUES TO PRODUCE A
LARGE AREA OF DISORGANIZED SHOWERS AND THUNDERSTORMS OVER THE
NORTHWESTERN BAHAMAS...THE SOUTHERN FLORIDA PENINSULA AND FLORIDA
STRAITS...CUBA...AND THE SOUTHEASTERN GULF OF MEXICO. UPPER-LEVEL
WINDS ARE FORECAST TO BECOME A LITTLE MORE CONDUCIVE FOR
DEVELOPMENT OF THIS LOW OVER THE NEXT COUPLE OF DAYS AS THE SYSTEM
MOVES WEST-NORTHWESTWARD AT 5 TO 10 MPH. THERE IS A MEDIUM CHANCE...
40 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL OR SUBTROPICAL
CYCLONE DURING THE NEXT 48 HOURS.

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

$$
FORECASTER KIMBERLAIN/PASCH

[Jag95]

The ULL is digging right into it.

Thank you for saying this, I was thinking maybe I was crazy. All I see is the ULL moving west into it and also wrapping dry air into the area as well. I don't think much of anything will come out of this and I hope this whole season will go down as a year with so much potential yet horrible upper environment. "2010, the year of shear"

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

IIRC, upper lows can actually aid in the development process, depending on the location, and especially when trailing the system. I'd be very surprised if this amounted to much, but you never know.

[KWT]

Yep upto 40% as I expected, probably the slight tightening up of that low thats probably made the difference, not a big deal but it all helps.

Low looks pretty stationary right now, convection increasing over the center from the south.

[MiamiHurricanes10]

I don't see the ULL going due west though, I see it heading NW at the moment...I mean that may not make a huge difference I'm not sure just yet...

That dry slot maybe an issue, but with an old frontal boundary lurking, there is likely going to remain enough instablity to allow some convection on the southern side of the circulation.

Oh yes it will, the ULL is the wild card for the development of 94L. If the ULL advects westward it will cause hostile upper level conditions for 94L which would cause chances at development to decrease. But, if the ULL advects further northward two things can happen:

1) The ULL will stack vertically causing favorable upper level winds for 94L along with subtropical characteristics at first (afterall a ULL is a cold low), but due to the 32C SSTs, a tropical transition afterward.

2) If the ULL goes north of 94L it will provide improved outflow for 94L, thus a "helper" for intensification.

[Ikester]

This is kind of Alicia-esk....anybody else think that?

[ronjon]

Starting to get a very subtropical look to low pressure system.

http://www.ssd.noaa.gov/goes/east/gmex/loop-vis.html

[Dean4Storms]

The ULL is not only expected to move westward across the northern Gulf but is also expected to weaken.

[Dean4Storms]

The low is now at 1010mbs according to the frontal plot on the sat. loop from ronjon posted.

[lrak]

JB's take

MONDAY 6PM
Southeast Gulf low looking better.

A look at the data buoys show pressure are falling and winds are increasing. Polaski Shoal has had WEST winds over 20 kts

p://www.ndbc.noaa.gov/show_plot.php?sta ... e_diff=-4& time_label=EDT


this is an impressive wind for so far south into what is normally a component from the southeast. My take is the hatch-it people will go to the red hatch soon on this.

http://www.ndbc.noaa.gov/station_page.php?station=PLSF1

Wow that is impressive.

[supercane]

Atlantic Tropical Weather Discussion


000
AXNT20 KNHC 100003
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON AUG 09 2010

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND
RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURES...
AN AREA OF LOW PRESSURE IN THE CENTRAL ATLC <snip>

A BROAD SURFACE LOW IN THE SE GULF OF MEXICO IS ANALYZED AS A
1011 MB LOW OFF THE W COAST OF FLORIDA NEAR 26N83W WITH A
SURFACE TROUGH EXTENDING NW ALONG 27N89W TO SE LOUISIANA NEAR
29N90W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE 120/150 NM
OF LINE FROM W CUBA NEAR 23N88W ALONG 26N87W TO OVER SE
LOUISIANA NEAR 29N90W. A SECOND SEABREEZE SURFACE TROUGH
EXTENDS NE FROM THE SURFACE LOW OVER THE W COAST OF THE FLORIDA
PENINSULA ENHANCING SIMILAR ACTIVITY INLAND AND WITHIN 60 NM
ALONG THE FLORIDA COAST S OF 29N. UPPER LEVEL WINDS ARE FORECAST
TO BECOME A LITTLE MORE CONDUCIVE FOR DEVELOPMENT OF THIS LOW
OVER THE NEXT COUPLE OF DAYS AS THE SYSTEM MOVES W-NW AT 4 TO 8
KT. THERE IS A MEDIUM CHANCE OF THIS SYSTEM BECOMING A TROPICAL
OR SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS.

[KWT]

Starting to get a very subtropical look to low pressure system.

http://www.ssd.noaa.gov/goes/east/gmex/loop-vis.html

I've been thinking about the same thing, if anybody here has been watching Dianmu in the WPAC, this thing is nearly a carbon copy of that system, its quite uncanny, tohugh of course the WPAC was far more convective, but all the same features were in place, like a ULL nearby, etc.

[Dean4Storms]

Sat. loop with wind obs, definitely trying to close off and tighten. Still broad but picking up steam. If deep convection fires off tonight over or near the center we could see a TD by tomorrow IMO.


http://rammb.cira.colostate.edu/ramsdis ... _floater_2

[KWT]

The next thing I'm looking for is to see the LLC tighten up a little bit, possibly with the LLC trying to tuck itself into the southern convection...if we get that or a convective burst further north over the broad low, we probably go Code Red.

[wxman57]

Winds around the low in the 15-20 kt range on the south and southwest sides. Key west has SW 20 kts. NW winds 15 kts about 80 miles NW of Key West. NE side is mostly over land, so only 5-10 kts there from the east and southeast. Pressure falling offshore. I think there's a better than 50% chance this will be Danielle on Wednesday morning. Most likely a weak TS moving inland into SE LA Thursday morning. Possibly 40-50 mph winds offshore. Maybe some TS winds in coastal areas of SE LA. That's assuming it moves inland there.

[dixiebreeze]

Offf shore Pasco County, Fla. west coast just north of Tampa:

Conditions at 42021 as of
(7:40 pm EDT)

Wind Direction (WDIR): NE ( 40 deg true )
Wind Speed (WSPD): 9.7 kts
Wind Gust (GST): 9.7 kts
Atmospheric Pressure (PRES): 29.84 in
Air Temperature (ATMP): 85.5 °F
Water Temperature (WTMP): 87.8 °F
Combined plot of Wind Speed, Gust, and Air Pressure