Vigorous tropical wave in Eastern Atlantic

[MiamiensisWx]

I made this thread per Luis' request. You can continue the discussion.

[cycloneye]

Yes,keep it going here in a new fresh thread.

[gatorcane]

Here is the wave the models are bullish on:

Look at 10N, 10W.

[skysummit]

There's something a little different about this wave. We've been used to seeing waves over Africa with lots of convection only to lose the convection once offshore. This wave has some convection, but not nearly as much as previous waves. The main difference I see is its structure...it's built quite nicely.

[windstorm99]

Looks ok but has some fighting to do with the SAL right above it.

[skysummit]

Looks ok but has some fighting to do with the SAL right above it.

As long as it comes offshore with a nice moisture envelope, it'll be fine.

[gatorcane]

If it stays at 10N as it traverses the MDR as the models are predicting, than it will be just a little south of the major SAL envelope as shown by this pic:

[MiamiensisWx]

Personally, I'm not jumping on the "development" bandwagon. All global models maintain the strong 500 mbar Azores ridge over the next several days. The presence of this ridge indicates more easterly shear and a continuance of the stable mid-level environment. A new SAL wave will exit Africa within 24 hours. We need a large-scale pattern change if we want MDR development within the next several weeks. Here's some outlines:

1) The western Atlantic trough should move away from the area. Upper-level shear is too hostile for Caribbean development, and this trough has suppressed the Bermuda ridge (thus the stronger Azores high/unfavorable eastern Atlantic). This demonstrates my next point...

2) The western "death ridge" must shift east - a downstream trough should dig into the West Coast (in order to alter the upper-air Northern Hemispheric pattern). You want a stronger Bermuda ridge and a tendency for subtropical anticyclones - this trend would weaken the persistent Azores ridge (meaning more favorable low-level environment in the MDR)

3) The downstream flow over eastern Canada must relax - the westerlies should lift northward

If we don't observe some significant changes, you can bet on a hostile Cape Verde region.

[gatorcane]

Good analysis Miami ini fact shear tendency analysis supports your claims.

But the models are probably counting on the shear in the Western Atlantic to die off substantially in about 10 days. I agree with them because usually shear dies off quickly by mid to late August.

[Derek Ortt]

model shear forecasts are less reliable than is Phil Mickelson's driving. For this reason, I do not place much if any credence in upper wind forecasts, especially beyond 24-48 hours. The reason is poor initialization due to a lack of data

[ronjon]

Personally, I'm not jumping on the "development" bandwagon. All global models maintain the strong 500 mbar Azores ridge over the next several days. The presence of this ridge indicates more easterly shear and a continuance of the stable mid-level environment. A new SAL wave will exit Africa within 24 hours. We need a large-scale pattern change if we want MDR development within the next several weeks. Here's some outlines:

1) The western Atlantic trough should move away from the area. Upper-level shear is too hostile for Caribbean development, and this trough has suppressed the Bermuda ridge (thus the stronger Azores high/unfavorable eastern Atlantic). This demonstrates my next point...

2) The western "death ridge" must shift east - a downstream trough should dig into the West Coast (in order to alter the upper-air Northern Hemispheric pattern). You want a stronger Bermuda ridge and a tendency for subtropical anticyclones - this trend would weaken the persistent Azores ridge (meaning more favorable low-level environment in the MDR)

3) The downstream flow over eastern Canada must relax - the westerlies should lift northward

If we don't observe some significant changes, you can bet on a hostile Cape Verde region.

Yes, Miami that is the current set up. But the long-range models (GFS) are now fairly consistently showing the Bermuda Ridge building in strength (both at the surface and 500 mb) and expanding westward over the eastern US after this east coast trough exits. Tropical cyclone development is enhanced under stronger upper air ridging. Shear is dropping across the Atlantic and should continue as this pattern becomes established. Unless something totally anomalous happens, climatology would argue for this transition. Indeed, the latest NOAA forecast is an 85% probablity of an above-average storm season. They must agree that this pattern will change.

[Vortex]

The wave over western Africa this morning has a nice low-mid level circulation already with it...This is the much anticpated wave/low depicted by various models to become a cyclone in the coming days...

http://oiswww.eumetsat.org/SDDI/cgi/lis ... 0#controls

[Vortex]

When you put in motion make sure u click on the dropdown box to get the most recent image then press play...

[x-y-no]

I'm going to merge this into the other thread on this wave (assuming I can remember how to do that )


Huh ... managed it finally ...

Seems the moderator tools aren't too Opera-frindly.

[cycloneye]

NRL Panoramic view image

Convection is not as plenty right now but it is easy to see the turning around 9-10n.This image updates every half an hour.

[cheezyWXguy]

NRL Panoramic view image

Convection is not as plenty right now but it is easy to see the turning around 9-10n.This image updates every half an hour.

That may not necessarily be a bad thing that convection isnt huge right now...as it seems that the huge waves with a lot of convection tend to dissapate faster

[cycloneye]

This is the full disk image from the 18:00z time.Convection has increased compared to this morning.

For those who dont have access to the images,you can register for free at this link below.

http://www.sat.dundee.ac.uk/registerql.html

[Fego]

GFS graphic data 12Z

[cycloneye]

NEW TROPICAL STORM FORECAST TO DEVELOP AFTER 60 HOURS

FORECAST POSITION AT T+ 60 : 12.3N 21.7W



VERIFYING TIME POSITION STRENGTH TENDENCY

-------------- -------- -------- --------

00UTC 12.08.2007 12.3N 21.7W WEAK

12UTC 12.08.2007 12.7N 25.9W MODERATE INTENSIFYING RAPIDLY

00UTC 13.08.2007 13.3N 28.5W MODERATE WEAKENING RAPIDLY

12UTC 13.08.2007 13.3N 32.3W WEAK WEAKENING SLIGHTLY

00UTC 14.08.2007 13.3N 35.8W WEAK WEAKENING SLIGHTLY

12UTC 14.08.2007 13.4N 39.4W WEAK INTENSIFYING SLIGHTLY

00UTC 15.08.2007 14.0N 42.4W WEAK WEAKENING SLIGHTLY

12UTC 15.08.2007 14.8N 46.3W WEAK LITTLE CHANGE



This is the text from the 12z UKMET.

[cycloneye]

The conservative NOGAPS joins the combo of models for this wave.



12z NOGAPS animation

By the way it also shows something in the Gulf.