ATL: INVEST 93L - Discussion

[cycloneye]

AL, 93, 2014091118, , BEST, 0, 104N, 204W, 20, 1009, DB, 0, , 0, 0, 0, 0,
AL, 93, 2014091200, , BEST, 0, 106N, 216W, 20, 1009, DB, 0, , 0, 0, 0, 0,
AL, 93, 2014091206, , BEST, 0, 110N, 231W, 20, 1009, DB, 0, , 0, 0, 0, 0,
AL, 93, 2014091212, , BEST, 0, 114N, 245W, 20, 1009, DB

Thread at Talking Tropics forum that was the topic for this area.

viewtopic.php?f=31&t=116725&p=2413416#p2413416

[Bizzles]

20/20

Shower activity associated with a tropical wave located south of
the Cape Verde Islands is showing some signs of organization. This
system, however, is forecast to move westward or west-northwestward
at around 10 mph toward an area unfavorable for development.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...20 percent.

[cycloneye]

Looking good.

[cycloneye]

93L SSD Floater

[wzrgirl1]

No model runs yet?

[weatherfanatic]

Right in time with height of season we have 3 systems, two of interest possibly. Some sgetti models are out but not the whole runs yet on invest 93L.

[Hammy]

Zero model support at the moment.

[cycloneye]

Shower activity associated with a tropical wave located south of
the Cape Verde Islands continues to show signs of organization. This
system, however, is forecast to move westward or west-northwestward
at around 10 mph toward an area unfavorable for development.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...20 percent.

[Gustywind]

Not mentionned as a special feature... but a low pressure has formed in vicinity of the twave.

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI SEP 12 2014

A TROPICAL WAVE EXTENDS FROM 5N25W TO 15N24W...THROUGH A 1011 MB
SURFACE LOW NEAR 11N25W...MOVING W AT 10-15 KT. THE LOW LEVEL
CIRCULATION IS WELL DEFINED AROUND THE LOW WITH NUMEROUS
MODERATE AND ISOLATED STRONG CONVECTION FROM 11N-13N BETWEEN 24W-
27W. ELSEWHERE...SCATTERED MODERATE CONVECTION IS FROM 9N-15N
BETWEEN 24W-29W

[BigA]

Not quite zero model support: the GEM (Canadian) develops it, but of course it tends to develop everything. I'd imagine that the NHC is pretty sure that there will be strong wind shear in the central Atlantic. I'm not certain I see it on the global models, but I trust them unless I can see other models besides the Canadian on board.

[cycloneye]

18z Best Track.

AL, 93, 2014091218, , BEST, 0, 118N, 259W, 20, 1009, DB

[cycloneye]

Shower activity associated with a tropical wave located south of
the Cape Verde Islands continues to show signs of organization. This
system, however, is forecast to move westward or west-northwestward
at around 10 mph toward an area unfavorable for development.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...20 percent.

[cycloneye]

00z Best Track:

AL, 93, 2014091300, , BEST, 0, 120N, 268W, 20, 1009, DB

[galaxy401]

Shower activity associated with a tropical wave located south of
the Cape Verde Islands continues to show signs of organization. This
system, however, is forecast to move westward or west-northwestward
at around 10 mph toward an area unfavorable for development.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...20 percent.

That seems to be just a copy and paste from the last outlook...

[StrongWind]

Now at 30%

2. Shower and thunderstorm activity associated with a tropical wave
located southwest of the Cape Verde Islands continues to show signs
of organization. Some development of this system is possible during
the next day or so before it moves westward or west-northwestward at
around 10 mph into an area unfavorable for development.
* Formation chance through 48 hours...medium...30 percent.
* Formation chance through 5 days...medium...30 percent.

[Gustywind]

Mentionned as a special feature.

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT SEP 13 2014

...SPECIAL FEATURES...

TROPICAL WAVE EXTENDS FROM 07N27W TO 16N27W MOVING W AT 10-15
KT. A 1009 MB LOW IS CENTERED ALONG THE WAVE AXIS AND REMAINS
EMBEDDED WITHIN THE MONSOON TROUGH NEAR 12N27W. THE WAVE
COINCIDES WITH BROAD 700 MB TROUGHING N OF 07N BETWEEN 22W-33W.
ISOLATED MODERATE CONVECTION IS FROM 11N-14N BETWEEN 27W-29W

[cycloneye]

8 AM TWO:

Shower activity associated with a tropical wave located southwest of
the Cape Verde Islands has become a little less organized this
morning. Some development of this system is still possible
before it moves westward or west-northwestward at around 10 mph into
an area unfavorable for tropical cyclone formation.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...20 percent.

[Bizzles]

Based on my extensive analysis, I give this a 20% chance for development. Just IMO.

[lordkev]

What is causing the recent Cape Verde waves to head out to sea before even reaching the Lesser Antilles? I noticed that earlier in the season they were almost all heading this way, but are now taking a more northwesterly track. Is it timing of the season, or just the ridges that happen to be in place at the moment? Sorry if this is obvious, I'm a newbie.

[USTropics]

What is causing the recent Cape Verde waves to head out to sea before even reaching the Lesser Antilles? I noticed that earlier in the season they were almost all heading this way, but are now taking a more northwesterly track. Is it timing of the season, or just the ridges that happen to be in place at the moment? Sorry if this is obvious, I'm a newbie.

Frontal boundaries that are pushing off of the U.S. East coast break down the ridging in the mid Atlantic, allowing these to escape to the north (especially developed systems where tendencies are to follow the lowest pressure).

Here is a surface analysis from the OPC detailing this: