Vigorous Wave coming off Africa

As of 2:00 am EDT Thu Aug 3 2017 ...
A large area of showers and thunderstorms near the west coast of
Africa is associated with a tropical wave. Environmental conditions
are forecast to be conducive for gradual development, and a tropical
depression could form by early next week over the tropical Atlantic
Ocean. This system is forecast to move toward the west or west-
northwest at 10 to 15 mph for the next several days.

* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...medium...50 percent.

 

Flhurricane.com : ""August beings (sic) the ramp up in earnest into the peak of the Atlantic Hurricane Season toward the climatological peak, which is the second half of August and most of September. This is the time of year where we watch all areas in the tropics and the most surprises tend to happen. It's also the time when conditions tend to be the best for development, and this year is no exception to that.

In the far east Atlantic, a wave has emerged from Africa in a very good position to develop, and because of this the National Hurricane Center requested an investigation area be put on it almost immediately. This system, tagged as 99L now has a 50% chance for development and multiple model support for it, so it's likely by the weekend we'll have a depression or named storm to track across the Atlantic. This does not guarantee a system will make it across, but history tells us that everything this time of year should be monitored closely.

If it were to develop and maintain itself it would likely be closest to the Caribbean in the middle of next week, and closer to the US late next week. See the forecast lounge for long range discussion and speculation on the system. There are factors that could keep it weak and hamper development, so out this far its impossible to say where or how strong it could be."

And, NHC at 8:00am puts it at 60% in 5 days. Seems like undercall.
http://www.nhc.noaa.gov/gtwo.php?basin=atlc&fdays=5

Also something flaring in east Caribbean. Stay tuned...

 

This is now 99L.
Here's what flhurricane.com says

"Long range speculation includes watching the global (and other) forecast models to watch for trends, when a system is still an invest and not fully developed things can (and do) change wildly from run to run, but they tend to vary less as time goes on. These models are helpful in that they give a general path to look for, and we look for consensus and stability between runs to gauge confidence in what they do. many times the position of the system in the model isn't as important as the conditions (Ridges/troughs/lows/upper level lows/dry conditions) around it.

That said, here's the first model set for 99L:

0z Euro: Not as strong as it was on the prior run, but it has it crossing the leewards as a Tropical Storm Tuesday night, then falling apart int the Caribbean afterwars (another system near the Yucatan starts going in the Bay of Campeche).

6z GFS: Develops a hurricane around 40W in the Central Atlantic Monday morning, keeps it north of the Caribbean islands, and bends it back west (north of the Bahamas), and has a major hurricane landfalling in coastal Georgia near Brunswick/St..Simons on Thursday August 17th (2 weeks from today). The 0z run prior to this had the same result. After landfall the 6z GFS turns it northward inland over North Georgia then eastern Tennessee (Knoxville) into Kentucky and Indiana weakening rapidly. (with a ton of rain).

The fact the models want to push this so far west implies the high will be strong around that time, which would increase the odds for some sort of impact on the land US down the road, if it doesn't stay south and go through the Caribbean like the current Euro Shows. So some sort of impact is likely, to what degree and where (islands vs US) is still up in the air. If the trend moves east during the next few runs, out to sea becomes more likely.

Way too early to say which is going to be more correct, nothing has developed yet, and the first runs are typically very wrong.

 

And from NHC:

Disturbance 1: 30% Chance of Cyclone Formation in 48 Hours
As of 2:00 pm EDT Thu Aug 3 2017 ...
A vigorous tropical wave accompanied by a broad low pressure system
is producing a large area of cloudiness and showers more than 300
miles south-southeast of the Cabo Verde Islands. Environmental
conditions are forecast to be conducive for gradual development, and
a tropical depression is likely to form by early next week over the
eastern or central tropical Atlantic Ocean. This system is forecast
to move toward the west or west-northwest at 10 to 15 mph for the
next several days.

* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...high...70 percent.

 

Patience grasshopper....

 

Pretty exciting Mitchell! Thanks for posting that.

As of 2:00 am EDT Fri Aug 4 2017 ...
A large and complex area of disturbed weather, associated with a
broad low pressure system, extends from about 400 miles south of
the Cabo Verde Islands to about 600 miles southwest of the Cabo
Verde Islands. Environmental conditions are forecast to be
conducive for gradual consolidation and development, and a tropical
depression is likely to form by early next week over the eastern or
central tropical Atlantic Ocean. This system is forecast to move
toward the west or west-northwest at 10 to 15 mph for the
next several days.

* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...high...80 percent.