Disturbed weather in Eastern Atlantic (Is invest 95L)

[wxman57]

192hrs - 27.5N/54.3W 986mb (I get data in before it's online). Shows it recurving, but I wouldn't be so sure just yet. Much will depend on what happens off the East U.S. Coast over the next week.

31.5N/55W at 216hrs. Moving due north at that time.

[Steve H.]

Just doesn't seem logical to have a northern stream Low pressure area hang up and wait for the ridge to break down and "merge" with a tropical low. Just doesn't look right at this time of year.

[cycloneye]

For those peeps who dont not have the link to the new project of testing tropical waves (PGI-27L,30L, 31L,33L) etc, here it is. There are many features in there with each individual pouch wave.

http://www.met.nps.edu/~mtmontgo/storms2010.html

[MiamiHurricanes10]

00z ECMWF -- Develops PGI31L.
12z GFS -- Develops PGI31L.
00z CMC -- Develops PGI31L.
00z UKMET -- Undoubtedly intensifies PGI31L, however, a stronger PGI33L absorbs PGI31L later in the run.
12z NOGAPS (Run not completed. Currently finished through 120 hours) -- Quite unclear as to what it develops, but it does seem to make an attempt to develop both PGI31L and PGI33L with PGI33L becoming dominant.

Based on the latest run from our best global models its pretty clear cut as to what is being developed. Now, it's time to sit back in watch.

I'll post what the 12z CMC shows as soon as it comes out...probably at any minute.

[gatorcane]

Just doesn't seem logical to have a northern stream Low pressure area hang up and wait for the ridge to break down and "merge" with a tropical low. Just doesn't look right at this time of year.

I mean look how deep this trough is digging? This is really not expected at all this time of year. We haven't had a trough dig that deep for several months....probably have to look back to March or April.

[Wx_Warrior]

Not much behind it either.

[gatorcane]

Not much behind it either.

Yeah should this one not threaten the US or Islands, the GFS keeps insisting run after run that nothing looks like it will for possibly a couple of weeks..........in fact nothing even develops in the next 14 days besides this system. Very strange things going on in weather, a trough that should not be there --- maybe 1 system in two weeks, as we come up to the peak of the season...hmmmmm

[MiamiHurricanes10]

Just doesn't seem logical to have a northern stream Low pressure area hang up and wait for the ridge to break down and "merge" with a tropical low. Just doesn't look right at this time of year.

I mean look how deep this trough is digging? This is really not expected at all this time of year. We haven't had a trough dig that deep for several months....probably have to look back to March or April.

As usual, the GFS overdoes the amplification of shortwave troughs. I mean this is still "far out" but, I'm not buying into any recurvature...yet.

[Aric Dunn]

00z ECMWF -- Develops PGI31L.
12z GFS -- Develops PGI31L.
00z CMC -- Develops PGI31L.
00z UKMET -- Undoubtedly intensifies PGI31L, however, a stronger PGI33L absorbs PGI31L later in the run.
12z NOGAPS (Run not completed. Currently finished through 120 hours) -- Quite unclear as to what it develops, but it does seem to make an attempt to develop both PGI31L and PGI33L with PGI33L becoming dominant.

Based on the latest run from our best global models its pretty clear cut as to what is being developed. Now, it's time to sit back in watch.

I'll post what the 12z CMC shows as soon as it comes out...probably at any minute.

I know its all fun to try and figure out what the models are trying to do I do it to ..lol... but at this point the individual waves that emerged over the last few days are almost completely not track-able and have essentially become a large area of broad cyclonic turning. There is not one wave that develops on its own. The interaction of all the energy/ vorticity leads to TC in these types of scenarios. you could just as easily put a location in the middle of the huge area and run the models and get basically the same output.

[OuterBanker]

BTW, thanks Cycloneye for such a wonderful site.
Go Navy! Most appropriate. Live just a little over an hour from the worlds largest naval base.

[MiamiHurricanes10]

That's true, Aric Dunn. This has just been a big collage of tropical waves combining to try and form into a tropical cyclone.

[Vortex]

With that type of trough in play the only systems we will need to worry about will be W of 60W.

[MiamiHurricanes10]

With that type of trough in play the only systems we will need to worry about will be W of 60W.

Yes, but you are not going to see a trough that digs that south in August nor September especially when we are in a negative phase of the NAO...we just aren't. And it's the GFS, know for over-amplifying troughs.

[MiamiHurricanes10]

Interesting 12z CMC. Develops PGI31L and shoots it northward. Then, when it meets the subtropical ridge it heads west. Towards the end of the run it begins WNW motion.

http://moe.met.fsu.edu/cgi-bin/cmctc2.cgi?time=2010081912&field=Sea%20Level%20Pressure&hour=Animation

[gatorcane]

Yes but nearly all models including the CMC keep showing the pesky large low hanging off the Northeastern CONUS for days and days. If the CMC extended its run it would send this thing to fishland.

As long as that hangs around, anything headed for the CONUS is recurving..........what a good time to have this low here as we head to the peak of the season. We may look back and thank that low for recurving some systems.

[cycloneye]

20%

ABNT20 KNHC 191743
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT THU AUG 19 2010

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

SHOWERS AND THUNDERSTORMS HAVE INCREASED OVER THE PAST SEVERAL HOURS
IN ASSOCIATION WITH A TROPICAL WAVE THAT IS MOVING WESTWARD AT
ABOUT 15 MPH OVER THE WESTERN CARIBBEAN SEA. HOWEVER...NO
SIGNIFICANT DEVELOPMENT IS EXPECTED BEFORE THIS SYSTEM MOVES OVER
THE YUCATAN PENINSULA AND CENTRAL AMERICA TONIGHT AND EARLY FRIDAY.
THERE IS STILL A LOW CHANCE...10 PERCENT...OF TROPICAL CYCLONE
FORMATION DURING THE NEXT 48 HOURS.

A LARGE AREA OF DISTURBED WEATHER EXTENDS FROM THE WEST COAST OF
AFRICA TO THE SOUTH OF THE CAPE VERDE ISLANDS. THE ASSOCIATED
SHOWER AND THUNDERSTORM ACTIVITY IS DISORGANIZED...BUT
ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR SOME DEVELOPMENT OF
THIS SYSTEM AS IT MOVES SLOWLY WESTWARD. THERE IS A LOW
CHANCE...20 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS.

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

$$
FORECASTER BERG/PASCH

[MiamiHurricanes10]

Not bad...20%.

[cycloneye]

The yellow circle includes from PGI-31L to PGI-33L.

[hurricaneCW]

With such a trough low in the western Atlantic, this storm may recurve around 50-55W. The CMC like this mornings GFS really amplifies that low off the mid-atlantic coast to the point where you have to wonder if that in itself will be another tropical system.

[KWT]

Yes, but you are not going to see a trough that digs that south in August nor September especially when we are in a negative phase of the NAO...we just aren't. And it's the GFS, know for over-amplifying troughs.

The current set-up is VERY condusive for troughing, the GFS maybe a little overdone but all it means is it recurving at say 60W rather then 50W...and trust me in -ve NAO's you can get some deep troughs due to the amplified jet pattern and the PNA supports it as well, in fact its very impressive to see how much supports a deep trough out there, hence why we are seeing systems and even tropical waves recurve before 65W...

This one is certain recurve IMO...as I've been thinking for a long time now...

ps, this one should be an invest pretty soon IMO...