Vigorous tropical wave in Eastern Atlantic

[ronjon]

This wave is strong with almost perfect symmetry. Everything looks set for development once it reaches the ocean.

http://www.nrlmry.navy.mil/sat-bin/display10.cgi?SIZE=full&PHOT=yes&AREA=mediterranean/sahara&PROD=ir&TYPE=ssmi&NAV=tropics&DISPLAY=Latest&ARCHIVE=Latest&CGI=tropics.cgi&CURRENT=20050724.2115.msg1.ir.x.sahara_dust.x.jpg&MOSAIC_SCALE=15

[Blown Away]

"Dean" is a perfect name for a big Cape Verde storm.

[Brent]

"Dean" is a perfect name for a big Cape Verde storm.

I'm more worried about Erin... has been a hurricane every single time and a major in 2001. Also likes land, hit FL twice in 1995 and came close to Bermuda in 2001.

[HurricaneMaster_PR]

Here it is. 1006mb low preparing to emerge off Africa...

18Z Surface Analysis Chart

[HurricaneMaster_PR]

8:05pm TPC Discussion

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 12N16W 12N26W 10N38W 8N47W 11N58W.
THE AXIS REMAINS QUIET THIS EVENING WITH ONLY SCATTERED MODERATE
CONVECTION WITHIN 150 NM S OF THE AXIS BETWEEN 50W-54W. STRONG
CONVECTIVE BLOW-UP IS OVER AFRICA APPROACHING THE COAST
ASSOCIATED WITH THE NEXT TROPICAL WAVE.

[cycloneye]

Here comes the wave that the models are latching on development,ready to emerge West Africa tommorow.

[Weatherfreak14]

Its going to be a very very intresting weekend.

[Sanibel]

The first southern 'feet' of this thing don't appear to be dissipating as they go over water. Hmm. However, the deep convection center over land appears to be well north and on a latitude near the Cape Verde Islands (and into the SAL pocket). Too far north for GFS initial.

[MiamiensisWx]

The first southern 'feet' of this thing don't appear to be dissipating as they go over water. Hmm. However, the deep convection center over land appears to be well north and on a latitude near the Cape Verde Islands (and into the SAL pocket). Too far north for GFS initial.

I think you're looking toward the wrong location. The pre-axis convection does not bear any indications of a dominant circulation. The actual mid-level circulation is centered further south (near 10N and 10.7W) than the strong convective activity. The sfc low likely will exit the coastline between 10.7N and 8.9N, so latitude will not play an inhibitive role against development. Most waves eventually "relocate" their primary rotation to a more favorable (i.e. southern) latitude when they leave western Africa.

[weatherman21]

After observing the 18Z GFS Run from this afternoon, the prediction continues the same concerning the tropical wave/area of low pressure which the GFS indicates will track wnw through the east Atlantic over the next week or so. After taking a look at a loop of the MeteoSat IR over western Africa, I also see what could be the wave in which the GFS is predicting which is now nearing the west African coastline. It appears the wave already contains an associated low pressure center, which I believe the GFS has been anticipating.
I could be wrong, but I feel the reason for the GFS being so consistant with this possible future cyclone is due to the model detecting an area of low pressure which has already been established over land in west Africa for a while. In regards to the long-term GFS solution, I do not rely whatsoever on such a long-term forecast that goes out past 7 days. The long-range GFS forecast has not been consistant at all which leads me to having zero confidence in the long-term. I too see a very interesting weekend ahead which will reveal whether the GFS has been correct or incorrect. I have posted a few screen captures below including the 18Z GFS Model Run below. I am still awaiting the latest GFS Run from 0Z to come out.

0Z MeteoSat IR of west Africa:



GFS Forecast for 15Z/11am EDT this morning:



GFS Forecast for 12Z on 8/16: (next Thursday)



GFS Forecast for 6Z on 8/17: (next Friday)

[Meso]

The SAL today,another wave behind the one emerging off africa at the moment should shield the preceding wave somewhat from invading SAL.

[cycloneye]

Full Disk Image at 12:00 UTC below.

It does not look bad as some suggest.The axis is still inside Africa but a good portion of the convection is now in the water.For those who cant see the image,you can register for free at link below.

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

[Sanibel]

I think you're looking toward the wrong location. The pre-axis convection does not bear any indications of a dominant circulation. The actual mid-level circulation is centered further south (near 10N and 10.7W) than the strong convective activity.

What I saw is playing out. The top part of the wave with the deepest convection is ripping off and heading towards Mauritania like the one last week. The bottom part of our wave is out over water in a slightly curved shape. It is holding convection so far, but no more than others I've seen earlier.

The real story here is that persisting SAL/ridge combo pumping storm preventer into the ITCZ. The last surge is still intact on satellite and nearly to the Antilles. It is the dominate feature in the Atlantic and the reason why the ITCZ is bare.

[SouthFloridawx]

I think you're looking toward the wrong location. The pre-axis convection does not bear any indications of a dominant circulation. The actual mid-level circulation is centered further south (near 10N and 10.7W) than the strong convective activity.

What I saw is playing out. The top part of the wave with the deepest convection is ripping off and heading towards Mauritania like the one last week. The bottom part of our wave is out over water in a slightly curved shape. It is holding convection so far, but no more than others I've seen earlier.
The real story here is that persisting SAL/ridge combo pumping storm preventer into the ITCZ. The last surge is still intact on satellite and nearly to the Antilles. It is the dominate feature in the Atlantic and the reason why the ITCZ is bare.

Well SAL is not a constant feature, and moves with the surface ridge and mid level features.
I am wondering what the wave that moved northward, causing rain in area's not usually expecting it, is going to do to the dust in that region?

[cheezyWXguy]

That is a lot of SAL, but its so weak...thats about as weak as it gets, except just off the african coast to the north...i dont think that will be a problem. And I knew at least some of yall would be writing this off right now. Its just feeling the effects of moving into a different environment...so for the next day, its gonna look terrible and everyone is gonna write it off. But when the shear lessens, as it moves west, it should begin to develop. In fact, by tomorrow I think it will look even better

[Opal storm]

Like I said before, I don't expect this to start developing until it's near or in the Caribbean and out from underneath the SAL.

[storms in NC]

Like I said before, I don't expect this to start developing until it's near or in the Caribbean and out from underneath the SAL.

IMO I don't think it will go into the caribbean.

[Hurricaneman]

Like I said before, I don't expect this to start developing until it's near or in the Caribbean and out from underneath the SAL.

or there is option b, the wave comes off africa, and pulls an Isabel and doesnt pay attention to the SAL to its north

[Meso]

Thing is that the SAL is lower than it's been for quite a while and seems to still be decreasing quite a bit..And even if the SAL does try surge forward after the wave,notice the convection to the N/N.E of the wave,it may well help the preceding wave in it's trek across.Dry air is also not as bad as it's been and the wave has quite a bit of moisture with it.

[weatherman21]

12Z Global GFS run from this morning shows the storm over the northern Lesser Antilles by next Friday. I have noticed in the GFS runs that the model is not only persistant in the track of this storm, but the model has also remained persistant in showing gradual strengthening through the entire-short-range period through next Saturday when the GFS places the storm over the northern Lesser Antilles. I am no expert in weather, but I see where the GFS is predicting 300MB winds to become symetrical around the possible cyclone once it tracks away from the Cape Verde Islands by Monday and 300MB winds become much stronger and more symetrical once the storm reaches the northern Lesser Antilles. The GFS also predicts the surface pressure gradiant within the storm to gradually tighten through the entire short-range. 18Z MeteoSat IR detects the wave now approaching the western edge of Africa.

18Z MeteoSat IR over west Africa:


12Z Global GFS run indicating the scenerio by next Thursday at 12Z:


12Z Global GFS run indicating the scenerio by next Saturday at 0Z: