ATL: INVEST 94L - Discussion

[gatorcane]

This invest looks rather good considering the Cape Verde season doesn't crank up for a couple of weeks usually. I am surprised there is not more traffic on this invest. Cape Verde season is upon us (and looks like it wants to get going early this year)!

[SouthDadeFish]

There's also this to worry about:



Upper-level convergence associated with a passing Kelvin wave will likely hinder convective activity over the next couple of days.

[cycloneye]

18z Best Track:

94L INVEST 150729 1800 12.1N 22.6W ATL 20 1010

[cycloneye]

Eric Blake ‏@EricBlake12 · 11m11 minutes ago
Storms have favored the low shear of the subtropics so far-- now let's see if Africa can produce. #climate #94L

[abajan]

nhc know some thing wx dont their pro

But wxman57 and SouthDadeFish are pros too!

[Weatherboy1]

Well, certainly something to keep an eye on - but the open Atlantic has been pretty hostile to many waves the past couple of years. With all the dry air and potential shear ahead of 94, I can't get too excited. Will have to see what we have left in 2-3 days.

[floridasun78]

nhc know some thing wx dont their pro

But wxman57 and SouthDadeFish are pros too!

but their dont agree with nhc pro i do call nhc guys as pro

[gatorcane]

Latest SAT imagery shows a pretty decent looking invest with signs of organization if you ask me. Convection is pulsing but not completely poofing unlike other strong waves we have seen move off Africa the past few weeks.

[MGC]

[quote="wxman57"]Looks like the Space Shuttle's RapidSCAT instrument caught the disturbance overnight. There's definitely an LLC, though it's not well-organized. It's best shot at development is over the next 24 hours before it encounters increasingly hostile conditions farther west.


57, the space shuttle has not flown in years. Perhaps you meant Space Station. Agree that 94L has a tough road ahead of it...at least we have something to watch......MGC

[cycloneye]

A tropical wave accompanied by a broad area of low pressure
continues to produce showers and thunderstorms a couple of hundred
miles south of the Cape Verde Islands. Some slow development of
this system is possible while it moves westward near 15 mph during
the next several days.
* Formation chance through 48 hours...low...10 percent
* Formation chance through 5 days...low...30 percent

[TheStormExpert]

TWO Graphic.

[CrazyC83]

I'm not too keen on this one. Shear looks very high once past about 40W so I think it needs to get going now if it wants to develop...

[Hammy]

Is there any reason anyone can figure why this, with zero model support, is getting 30% while the system off Florida (with at least limited model support) is getting 10?

[Yellow Evan]

Actually conditions aren't too bad shear wise, but it has dry air to face.

[gatorcane]

Is there any reason anyone can figure why this, with zero model support, is getting 30% while the system off Florida (with at least limited model support) is getting 10?

Hammy the ECMWF is showing some development the past few runs within 5 days so there is some model support on this one. But none of the other models show anything signficant. No doubt they are putting some weight in that model.

[TheStormExpert]

Is there any reason anyone can figure why this, with zero model support, is getting 30% while the system off Florida (with at least limited model support) is getting 10?

Hammy the ECMWF is showing some development the past few runs within 5 days so there is some model support on this one. But none of the other models show anything signficant. No doubt they are putting some weight in that model.

Yeah and only the GFS is showing development from the SE U.S. Coast low, so go figure.

[gatorcane]

Looking at the latest Atlantic wide-view water vapor loop, we see there is a pretty large area to the N and W of this invest which is fairly moist in the upper-levels of the atmosphere (black areas of the image). Note that the oranges (dry, stable air) is heading west and away from this invest:
http://www.ssd.noaa.gov/goes/east/tatl/wv-animated.gif

Now if we were to freeze the conditions across the MDR today while this invest headed west, yes it would get clobbered by that dry and stable air quickly. But the atmosphere is fluid and not constant.

Also looking at the MJO, we see that the MDR should have less stable and sinking air over the next week as we see the orange shading replaced by neutral and then light green (rising air):
http://www.cpc.ncep.noaa.gov/products/p ... hi/cfs.gif

So conditions do appear favorable for some slow development as the NHC has mentioned. Does anybody find it interesting the ECMWF is calling for some development of this invest while the GFS is not? Almost always it is the opposite deep in the MDR.

[blp]

Looking at the latest Atlantic wide-view water vapor loop, we see there is a pretty large area to the N and W of this invest which is fairly moist in the upper-levels of the atmosphere (black areas of the image). Note that the oranges (dry, stable air) is heading west and away from this invest:
http://www.ssd.noaa.gov/goes/east/tatl/wv-animated.gif

Now if we were to freeze the conditions across the MDR today while this invest headed west, yes it would get clobbered by that dry and stable air quickly. But the atmosphere is fluid and not constant.

Also looking at the MJO, we see that the MDR should have less stable and sinking air over the next week as we see the orange shading replaced by neutral and then light green (rising air):
http://www.cpc.ncep.noaa.gov/products/p ... hi/cfs.gif

So conditions do appear favorable for some slow development as the NHC has mentioned. Does anybody find it interesting the ECMWF is calling for some development of this invest while the GFS is not? Almost always it is the opposite deep in the MDR.

Indeed, setting up the conditions for a little flury of tropical wave activity in August. Let's see if any can make it across.

[Gustywind]

Stays at 10%/30%


000
ABNT20 KNHC 300515
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT THU JUL 30 2015

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

A tropical wave accompanied by a broad area of low pressure is
located a couple of hundred miles south-southwest of the Cape Verde
Islands. Although this system is currently producing a large area
of showers and thunderstorms, further development, if any, will be
slow to occur while it moves westward near 15 mph during the next
several days.
* Formation chance through 48 hours...low...10 percent
* Formation chance through 5 days...low...30 percent

$$
Forecaster Avila

[SouthDadeFish]

Looks like the upper-level convergence associated with the passing Kelvin wave is beginning to take its toll on this wave. Convection is much weaker than yesterday.