Invest 97L Observation, Interpretation & Analysis (#2)

[Air Force Met]

Folks this is a open wave oriented NE to SW. Additionally, if you look at the loops from this morning while convention has increased the cyclonic rotation has dimished. All cloud elements are moving toward a wnw and development if any is going to have to wait for another 24 hours or so.

I do not see this system becoming a depression anytime soon, and maybe not at all.

OK...I'll ask the same question as Derek: Rotation has decreased?

I don't think so. I think its just that you can't see it as much because it is covered with convection.

[curtadams]

Folks this is a open wave oriented NE to SW. Additionally, if you look at the loops from this morning while convention has increased the cyclonic rotation has dimished. All cloud elements are moving toward a wnw and development if any is going to have to wait for another 24 hours or so.

I do not see this system becoming a depression anytime soon, and maybe not at all.

*Flow* is like a wave, with a low pressure trough and vigorous cyclonic turning around the end not closed across the trough itself. But it's not like a wave in that the "trough" is the ITCZ itself. The system does have to detatch itself from the ITCZ, yes, but it's demonstrating the energy to do it. In the last few frames you see the ITCZ bending as the center moves north. I don't see a storm in the next few hours since it's still embedded in the ITCZ but I expect there will be relatively soon.

[Air Force Met]

Folks this is a open wave oriented NE to SW. Additionally, if you look at the loops from this morning while convention has increased the cyclonic rotation has dimished. All cloud elements are moving toward a wnw and development if any is going to have to wait for another 24 hours or so.

I do not see this system becoming a depression anytime soon, and maybe not at all.

Finally a voice of reason...


see this loop, http://www.atmos.washington.edu/~ovens/ ... nhanced+12

overall convection has decreased over tha past few hours. Development is possible, not imminent.

It hasn't decreased nearest the the area of maximum vorticty over the last 12 hours. This morning, all the convection was well ahead of the cyclonic turning. Now the convection is right over it.

As far as imminent development...not soon I agree...they won't upgrade without solid data...but it is much better organized overall than it was this morning.

[tropicsgal05]

I know this wave is along way yet but if it strengthens and gets in the GOM, any idea which direction it might take. I know they have a mind of their own as they say but maybe an idea?

[Weathermaster]

Why the TWO has not come out yet?

[ConvergenceZone]

Check out the visible loop with overlays, before the sun goes down - quite impressive compared to the last few days.
http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html

Well, one thing for sure, the rotation is certainly there and it looks like it's going to miss South America as it's beginning to pull away from the ITCZ. It's pretty evident now.

[Brent]

Why the TWO has not come out yet?

It's not late yet...

[bvigal]

Someone mentioned this earlier... buoy 41101 at 14.6N 56.2W is having a pressure drop.
5-day trend map:
http://www.ndbc.noaa.gov/show_plot.php? ... wdpr&uom=E

So is Barbados
http://weather.noaa.gov/weather/current/TBPB.html

[cycloneye]

Why the TWO has not come out yet?

Aparently they are typing a long paragrafh about the wave.

[dwg71]

AFM, All I'm saying is talk of landfall zone, major hurricane and the "big one" is way, way premature...

my untrained amateur opinions says 30-40% development to a named storm...I might be wrong.

[crown]

Folks this is a open wave oriented NE to SW. Additionally, if you look at the loops from this morning while convention has increased the cyclonic rotation has dimished. All cloud elements are moving toward a wnw and development if any is going to have to wait for another 24 hours or so.

I do not see this system becoming a depression anytime soon, and maybe not at all.

It sometimes happens where the ISP operates a caching server. Try purging your computer's cache before viewing the next set of loops.

[cycloneye]

TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
530 PM EDT WED AUG 23 2006

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

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON WEAKENING
TROPICAL STORM DEBBY...LOCATED OVER THE FAR EASTERN ATLANTIC ABOUT
610 MILES WEST-NORTHWEST OF THE CAPE VERDE ISLANDS.

A STRONG TROPICAL WAVE LOCATED ABOUT 325 MILES EAST-SOUTHEAST OF THE
WINDWARD ISLANDS IS MOVING WEST-NORTHWESTWARD AT ABOUT 20 MPH. THIS
SYSTEM HAS BECOME MUCH BETTER ORGANIZED TODAY...AND ENVIRONMENTAL
CONDITIONS APPEAR FAVORABLE FOR A TROPICAL DEPRESSION OR A TROPICAL
STORM TO DEVELOP DURING THE NEXT DAY OR SO. INTERESTS IN THE
WINDWARD ISLANDS SHOULD MONITOR THE PROGRESS OF THIS SYSTEM AS IT
COULD PRODUCE WIND GUSTS TO TROPICAL STORM FORCE ALONG WITH LOCALLY
HEAVY RAINFALL TOMORROW. AN AIR FORCE RESERVE UNIT RECONNAISSANCE
AIRCRAFT IS SCHEDULED TO INVESTIGATE THE SYSTEM THURSDAY
AFTERNOON...IF NECESSARY.

ELSEWHERE...TROPICAL STORM FORMATION IS NOT EXPECTED THROUGH
THURSDAY.

$$
FORECASTER STEWART

[Weathermaster]

Aparently they are typing a long paragrafh about the wave

Or maybe they are waiting for some data to upgrade...

[GeneratorPower]

I saw it said here that someone loses credibility when they disagree with the Pro Mets, or something to that effect. Not so. They lose credibility when they are proven wrong.

[Brent]

A STRONG TROPICAL WAVE LOCATED ABOUT 325 MILES EAST-SOUTHEAST OF THE
WINDWARD ISLANDS IS MOVING WEST-NORTHWESTWARD AT ABOUT 20 MPH. THIS
SYSTEM HAS BECOME MUCH BETTER ORGANIZED TODAY...AND ENVIRONMENTAL
CONDITIONS APPEAR FAVORABLE FOR A TROPICAL DEPRESSION OR A TROPICAL
STORM TO DEVELOP DURING THE NEXT DAY OR SO. INTERESTS IN THE
WINDWARD ISLANDS SHOULD MONITOR THE PROGRESS OF THIS SYSTEM AS IT
COULD PRODUCE WIND GUSTS TO TROPICAL STORM FORCE ALONG WITH LOCALLY
HEAVY RAINFALL TOMORROW. AN AIR FORCE RESERVE UNIT RECONNAISSANCE
AIRCRAFT IS SCHEDULED TO INVESTIGATE THE SYSTEM THURSDAY
AFTERNOON...IF NECESSARY.

Very strong wording.

[Stormcenter]

Mobile, AL NWS doesn't seem concerned at all and doesn't even mention 97L.

Area forecast discussion
National Weather Service Mobile Alabama
340 PM CDT Wednesday Aug 23 2006


Short term...(tonight through friday)...tropical airmass prevails
across the southeast this afternoon and will continue into the
extended. Very messy pattern also in place making for a difficult
pop forecast. Right now...visible satellite and water vapor imagery
showing an upper low spinning about 268 miles south-southeast of Dauphin Island.
A weak frontal boundary across south central Alabama continues to
drift southward. Area upper air observations show plentiful moisture
in place west/ precipitable water values from 2 to 2.15 inches across the central Gulf
Coast this morning. In fact...17z kvps observed sounding had 2.38
inches of precipitable water west/ a k-index of 38!!! water vapor imagery also
indicates a weakness across the area as we are in between two upper
level ridges. An upper shortwave moving southeastward around the
ridge across Texas currently helping a fire off thunderstorms across
southeast Arkansas and west central MS. Thunderstorms also increasing in coverage
along the front through central Mississippi into Alabama moving
toward the south and will hang on to scattered coverages through the
evening to handle this ongoing convection. However most of the
thunderstorms should weaken as they approach the coast.


23.12z models did not handle this feature particularly well west/ only
the GFS indicating this shortwave. This feature should be enough to
develop a weak wave of low pressure along the front tomorrow
afternoon. All of these features along west/ seabreeze formation
combine over the forecast area during peak heating tomorrow leading ME
to believe the high mav MOS probability of precipitation. Not to mention the precipitable water values
remain around 2-2.25 inches and west/ a nearly moist adiabatic
profile...only a little forcing will lead to widespread rainfall.
This profile is not supportive of damaging winds or large
hail...however very supportive of heavy rains. NAM continues to
develop a closed surface low over the central Gulf and move it northward
toward the north central Gulf Coast by Friday. NAM has been doing
this all year and will continue to discount this scenario. Upper
level ridging begins to rebuild some by Friday west/ slowly decreasing
chances of rain...but remain in the high chance category west/ an
active seabreeze expected. Widespread clouds and rainfall during the
afternoon periods will hold temperatures back some but high humidity
levels will still make it fell rather uncomfortable. /13




Long term...(saturday through wednesday)...deeply tropical airmass
continues over the area through the period. Broad upper ridge
develops across the region over the weekend. Ridge is not very
strong and plentiful lolvl moisture along west/ several small
boundaries scattered around will lead to continued scattered chances
of showers and thunderstorms. Showers and thunderstorms will begin
over the coastal waters early in the morning along the landbreeze
and gradually develop inland during the late morning and afternoon
hours. Continued nearly moist adiabatic profiles will make the
greatest threat heavy rainfall. By the start of the new week...an
upper trough moving across the northern tier states will send a surface
low across the NE with a trailing surface front sagging slowly into the
southeastern US. This front will again become quasi-stationary as it
moves into central MS/al/GA on Tuesday as its upper support lifts
out. Also...another upper low is forecast to move across the central
Gulf during this period...very similar to the conditions we have
today. These features will combine for an increased focus for mainly
diurnal rain showers/thunderstorm chances for the middle of the week. Warm and muggy
conditions will prevail...typical for mid-August...with temperatures not
too far off of climatological norms. /13


&&

[Weathermaster]

Cycloneye:

Any risk for PR? TWO says is moving WNW..

[Dean4Storms]

Definitely looks better organized and I think Recon finds a TS by tomorrow if this trend continues.

[skysummit]

I saw it said here that someone loses credibility when they disagree with the Pro Mets, or something to that effect. Not so. They lose credibility when they are proven wrong.

....and here they are proven wrong. Especially when the TWO mentions the possiblity of a TS in the next 1 - 2 days also.

[Brent]

Cycloneye:

Any risk for PR? TWO says is moving WNW..

I don't see any... it should be well south of there, similar to Emily or Ivan.