Wave just offshore Africa...Another player...

[Hyperstorm]

This is the first wave this year that holds together as it came off the coast and actually has grown in size and coverage of thunderstorms over the water meaning...SAL is slowly fading away...at least for now.

There are a few models that develop this feature and it has a great circulation on satellite imagery, combine that with thunderstorms holding together over water and better moisture in the mid-upper levels. This means business! This has higher potential for development that its predecessors as the previous wave lowered the pressures near the CV islands and provided more moisture in the area.

So, everyone let's get ready for the ride starting this weekend. It looks like we may have at the very LEAST 1 system, who knows 2?, or 3?? Who knows?

Stay tuned for a major increase in activity during the next month...

[Derecho]

Based on the soundings and satellite imagery, that's a wind surge, not a wave.

The actually wave is still moving (painfully slowly) but still rotating, over Guinea, and should finally come offshore sometime late tonight, possibly.

[Hyperstorm]

Aghh! This is one of the things of looking at a satellite imagery with one eye closed. Maybe I have to get some sleep. I have been rather sleepless lately...a lot of work to do! LOL

Well, well, well, let's see...I have to check the data this morning as this is one of the reasons why relying on satellite data only is not a good thing. I have been pretty cautious in the past when it comes to these wind surges, so I can't believe I missed this one. Thanks for letting me know.

I'll check the data and update later this morning...

[Hyperstorm]

Actually, Derecho, I believe that this has some sort of reflection at the surface. There are several things I base it on.

First, the forcing offshore Africa was impressive. The system was able to fire off thunderstorms over the water meaning that it has to have something at the surface. Wind surges come off Africa one way and stay that way until dissipation. Thunderstorms don't develop over the water with them. Second, there appears to be a circulation on satellite imagery and SAL in the CV islands indicate NE winds, probably indicating some sort of circulation. And lastly, there was a 3-4 mb drop of pressure in Dakar almost 24 hours ago, or about the same time the system went through there.

It might not be a wave like you said, but it could be a monsoon system (I don't think it's a wind surge) that could develop if it holds together. Sometimes, systems in the tropical Atlantic develop from disturbances that come out of the ITCZ and not necessarily from tropical waves.

We'll see what happens and give it the benefit of the doubt. Even if this one doesn't do anything, the increase of thunderstorms over water is a good sign conditions have changed...

[Derecho]

Wind surges cause pressure drops as well.

Problem is the winds in Dakar and Cap Skirring are out of the North and Northeast, just like the Cape Verdes.

[Hyperstorm]

Wind surges cause pressure drops as well.

Do they? Well, I just learned something new today. I knew that monsoon-type systems do drop pressures, but not wind surges. Thanks for that.

Problem is the winds in Dakar and Cap Skirring are out of the North and Northeast, just like the Cape Verdes

I noticed that too, but wanted to give it the benefit of the doubt and see what happens.

[cycloneye]

The latest discussion this morning doesn't mention the convection as part of a tropical wave.

SCATTERED MODERATE/STRONG
CONVECTION IS OFF THE AFRICAN COAST WITHIN 60 NM OF LINE FROM
11N18W-12N22W.

The wave axis is still inland and by tonight it will emerge and then be introduced but yes the time has arrived when that region of the world will be the hot spot.

[Ola]

It seems that it was a pretty significant wind surge which lowered pressures and the intense convection caused a mid-level low to form. Now over water, convection is warming and the rotation already looks lazy and ragged, as it happens with mid-level circulations with no support in the low levels, they die out.

[Derecho]

Pressure in Dakar is down to 1010 mb as the Eastern Feature finally approaches...

The GFS has a low with both the wind surge and the wave vort center (unlikely to be real.)

At worst, it's a really elongated wave/monsoon trough, but I really think the lead convection was a wind surge.....

[Hyperstorm]

Well, it looks like the system I talked about a few days ago was indeed a wave. (I wondered...It looked really impressive for it to have been just a wind surge.)

Anyway, the system was becoming disorganized this morning, but has since become better organized convection-wise, so Bonnie could not be ruled out. However, the one off Africa is REALLY impressive with convection firing OVER a circulation center that's in the water. This could easily develop as well.

I'm impressed by the hike in activity this weekend. I was expecting something like this, but not this early, especially with the dry MJO on top of us.