Tropical Wave with low in East Atlantic (Is invest 91L)

[somethingfunny]

What a strange looking upper level feature this is that grabs hold of this system and pulls it into a recurve on the 12z GFS:

http://i.imgur.com/l9Fqz.gif

I suspect that the system won't develop as quickly as the global models are suggesting... based on the hostile trends in the MDR this season.

Yeah,a quick developer in that run recurves more fast. But past runs had it much more weak moving west reaching or brushing the northern Lesser Antilles.

That is quite a ridge over the western Atlantic on these model runs...

[cycloneye]

Guess what sf, 18z GFS has a stronger ridge than at 12z and that is why the system goes more west and brushes the Leewards,BVI,VI and PR. In other words,the wiper game continues with the models especially with GFS.

[gatorcane]

It's way too early to say where this system ends up if it develops. We should have learned from Isaac when it formed from a wave off the coast of Africa to not put too much weight into the long-range models especially since both the GFS and ECMWF showed a pretty sharp recurve track in the MDR at one point.

[cycloneye]

Slowly things are starting to take shape even though the axis has not emerged West Africa.

Saved image.

[cycloneye]

A low pressure has been added on the 12z TAFB surface analysis.

[HurricaneFan]

According to the map it seems to have a stationary Moonsoon Trof in the Eastern Atlantic far to the north.Is that normal for this time of the year?
Could that be why the Tropical Wave to the WSW of the Cape Verde Islands is not looking like it's going anywhere,because it is stuck to it?
And would the stationary Moonsoon Trof have any effect on the Wave coming off the coast of Africa now?

[cycloneye]

Is taking forever for this thing to emerge completly the coast as is just crawling westward as you can see in this saved image from Thursday evening compared to the one 3 posts above from Wednesday night.

[blp]

Looking at the models today I see the models still having some difficulty with the strength of the ridge and the strength of the system. I see huge differences. I am not yet sold on a recurve. The trend today has been generally west.

00z GFS 264hr 32w curving out to sea
00z Euro 240hr recurve 50w

06z GFS 252hr approaching 60w -- major shift west from 00z


12z GFS 240hr 58w curving out to sea.
12z Euro 240hr seems to start to pull up around 65w

18z GFS 240 67w before pulling up.

Let's see what 00z GFS and Euro show.

[Hurricaneman]

0zGFS pretty much agrees with the 12ZGFS up and out at 58W, I have a feeling with this wave its going to be an Euro vs GFS battle again

[Blown Away]

06 GFS still spinning up a storm but continues to recurve. Persistent weak BH not allowing the systems to move near land, I think we can almost close the door on west bound systems landfalling in the CONUS.

[cycloneye]

06 GFS still spinning up a storm but continues to recurve. Persistent weak BH not allowing the systems to move near land, I think we can almost close the door on west bound systems landfalling in the CONUS.

And the NE Caribbean islands may have the door closed too for direct hits unless the ridge establishes after Leslie and Michael are gone. We may have to start to watch the SW/Western Caribbean for development on late September/October.

[redneck51]

Is taking forever for this thing to emerge completly the coast as is just crawling westward as you can see in this saved image from Thursday evening compared to the one 3 posts above from Wednesday night.

Here's a loop:

[tolakram]

You can animate 15 minutes a frame here: http://oiswww.eumetsat.org/IPPS/html/MS ... /index.htm

Full disc here: http://oiswww.eumetsat.org/IPPS/html/MS ... ESOLUTION/

False color visible here: http://oiswww.eumetsat.org/IPPS/html/MS ... /index.htm

and click full disc, high resolution on the left hand bar to create custom zoom areas.

Latest

[Aric Dunn]

surface obs in the are and sat.. Appears it has moved offshore with a fairly well defined llc. if convection builds nhc should mention it sometime the next couple two's

[Hurricaneman]

looks about 1* farther south than forecasted to come off of Africa by the models, and the 12zGFS 500 mb pattern kind of argues for a farther west solutin in the long run, it also randomly opens up a weakness at 204hrs but thats 8 1\2 days on a model interpretation which is subject to large errors

The only thing I can see for the next 5 to 7 days is almost due west and probably no stronger than a moderate tropical storm

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[cycloneye]

Bingo! Finnally,we have the introduction to Tropical Wave by TAFB,and with low pressure.

[Aric Dunn]

no mention at 2pm

[cycloneye]

2 PM TWD


TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI SEP 07 2012

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 12N16W TO 20N17W MOVING W AT 10-15
KT. A 1012 MB LOW IS CENTERED AT THE SOUTHERN EXTENT OF THE WAVE
AXIS NEAR 13N16W AND IS FORECAST TO EMERGE OFF THE W AFRICA
COAST DURING THE NEXT 24 TO 36 HOURS. MANY OF THE GLOBAL MODELS
SUGGEST AT A MINIMUM A BROAD LOW-LEVEL CYCLONIC CIRCULATION
LOCATING SE OF THE CAPE VERDE ISLANDS IN THE VICINITY OF 14N22W.
THE WAVE AXIS ITSELF IS HIGHLY EVIDENT IN TOTAL PRECIPITABLE
WATER AND SATELLITE IMAGERY WITH SCATTERED MODERATE CONVECTION
OCCURRING FROM 07N-14N BETWEEN 17W-22W.

[blp]

looks about 1* farther south than forecasted to come off of Africa by the models, and the 12zGFS 500 mb pattern kind of argues for a farther west solutin in the long run, it also randomly opens up a weakness at 204hrs but thats 8 1\2 days on a model interpretation which is subject to large errors

The only thing I can see for the next 5 to 7 days is almost due west and probably no stronger than a moderate tropical storm

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

The break looks to be between 55-65W. That break in the ridge has been consistent the last few days on the models with neither the Euro or GFS passing 67w. The difference I see in the 12z GFS run from the 06z is that it keeps it weaker longer and thus further west. If it manages somehow to stay weak enough to pass that break it could become trouble because past 65W the ridge looks to be building in on each of the model runs.

[gatorcane]

Yep BLP, I do see that past 65W over Eastern North America and the Western Atlantic, ridging seems to be building in the long-range. The question is how much can ridging build back in after Leslie and Michael are out of the picture? I still don't think a recurve is a definite despite the consecutive runs by the GFS and ECMWF showing the system hitting a break in the ridge.

For example here is the 12Z ECMWF 500MB flow at 144 hours. Look at the high pressure building down the eastern Seaboard of the United States. Also note the big break in the ridge left behind by Leslie around 50W-55W:



And here is the 12Z GFS at 168 hours which shows alot of high pressure over North America and no troughs upstream: