Tropical Wave (Pouch 12L) E Atlantic - (Is Invest 98L)

[SFLcane]

Two tweets by Levi Cowan:


Levi Cowan ‏@TropicalTidbits 10m
July pattern means we might get Chantal-like system: on-edge between development and no development. Will have to watch regardless.


Levi Cowan ‏@TropicalTidbits 22m
Two runs in a row of the GFS have now failed to develop the wave about to exit Africa. Development has never been supported by another model.


https://twitter.com/tropicaltidbits

Thought we were heading into more favorable outlook for these waves. Now were talking another chantal NO THANKS lol..i will check back mid august.

[gatorcane]

Looks like the GFS may indeed bust again!

[Alyono]

July 21st before we get the season cancels. Not bad. I'd say about average.

I think part of the frustration comes from the fact that a particular model or set of models like the GFS shows development of a tropical cyclone for like 5,6,7 consecutive runs which gives many the impression that maybe something will develop after all and then all of a sudden the GFS drops it. This development teasing, if you may, causes frustration for some people. I dont think this is the only reason for the season cancel posts but it plays a huge rule in that.

Sent from my HTC EVO 4G LTE

the parameterization scheme may be produce too much latent heat release. That would be my guess regarding the GFS

[blp]

July 21st before we get the season cancels. Not bad. I'd say about average.

I think part of the frustration comes from the fact that a particular model or set of models like the GFS shows development of a tropical cyclone for like 5,6,7 consecutive runs which gives many the impression that maybe something will develop after all and then all of a sudden the GFS drops it. This development teasing, if you may, causes frustration for some people. I dont think this is the only reason for the season cancel posts but it plays a huge rule in that.

Sent from my HTC EVO 4G LTE

the parameterization scheme may be produce too much latent heat release. That would be my guess regarding the GFS

Great, we now have the CMC which still overhypes development, the GFS which keeps showing phantom storms and now even in the short term and the Euro which can't handle cyclogensis well. Seems like the upgrades to the models have taken us a step backwards from years past.

[cycloneye]

Nothing at 2 PM.

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT SUN JUL 21 2013

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE NEXT 48 HOURS.

$$
FORECASTER STEWART

[TheStormExpert]

It seems as if the Atlantic was more favorable for development back in June than it is now. Especially the Tropical Waves that came off Africa were holding together longer and were more robust looking.

Just goes to show you can't fully judge what the peak months of the season will be like from what is going on at the very beginning of the season!

Even last July seemed slighty more favorable for any Tropical development than this July.

[TheStormExpert]

Also don't the models usually start showing development of major storms in the long range this time of year which means things are going to be picking up soon? As of now there not showing a thing which might be saying something??

[TheStormExpert]

Doesn't look too bad right now but most likely start to struggle real soon, due to all that dry air!

[cycloneye]

Here is the 2 PM discussion of wave.

TROPICAL WAVE EXTENDS FROM 09N12W TO 17N18W MOVING W AT 10-15
KT. THIS WAVE IS BEGINNING TO EMERGE OFF THE COAST OF WEST
AFRICA AND EXHIBITS FAVORABLE MID-LEVEL VORTICITY ENERGY IN THE
VICINITY OF 12N15W ALONG THE WAVE AXIS. GLOBAL MODELS INDICATE
THE WAVE COINCIDES WITH A WEAK 700 MB TROUGH ALONG 16W THAT IS
FORECAST TO MOVE WESTWARD ON THE SOUTHERN PERIPHERY OF CENTRAL
ATLC RIDGING DURING THE WEEK AHEAD. SCATTERED MODERATE
CONVECTION IS FROM 06N-12N BETWEEN 13W-17W.

[Alyono]

It seems as if the Atlantic was more favorable for development back in June than it is now. Especially the Tropical Waves that came off Africa were holding together longer and were more robust looking.

Just goes to show you can't fully judge what the peak months of the season will be like from what is going on at the very beginning of the season!

Even last July seemed slighty more favorable for any Tropical development than this July.

Huh? There were ZERO storms last July

[gatorcane]

It seems as if the Atlantic was more favorable for development back in June than it is now. Especially the Tropical Waves that came off Africa were holding together longer and were more robust looking.

Just goes to show you can't fully judge what the peak months of the season will be like from what is going on at the very beginning of the season!

Even last July seemed slighty more favorable for any Tropical development than this July.

The Cape Verde season doesn't even start until mid August when you look at climatology and so it's very possible (and likely) conditions for Cape Verde systems will be much better in a few weeks then they are now.

If this pouch does develop in the eastern Atlantic, it would be quite unusual for this time of year.

[RL3AO]

Everyone calm down. Its July 21st. We've had three named storms already. Tropical waves aren't supposed to develop at 30W on the last part of July.

[TheStormExpert]

It seems as if the Atlantic was more favorable for development back in June than it is now. Especially the Tropical Waves that came off Africa were holding together longer and were more robust looking.

Just goes to show you can't fully judge what the peak months of the season will be like from what is going on at the very beginning of the season!

Even last July seemed slighty more favorable for any Tropical development than this July.

Huh? There were ZERO storms last July

Yeah but wasn't last July very slightly more favorable? Especially the second half of July.

[cordelia667]

Hi All.

As I live in St. Croix, US Virgin Islands, I have been monitoring that That should come off Africa Monday, 07-22-13, into E Atlantic. The GFS had it more aggressive in possibly forming into at minimum a TD, and soon. Still it has quite a distance before getting close to we, in the Virgin Islands. I would love any of your opinions as to the development of this TW, and, if so, strength? Thanks, Cordelia (STX, VI)

[ninel conde]

here is the clear reason the wave will die.

http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... hour=096hr

it will run into incredibly high pressure, not to mention exceptionally dry air. that green in the east pacific needs to be over the tropical atlantic.

[cordelia667]

here is the clear reason the wave will die.

http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... hour=096hr

it will run into incredibly high pressure, not to mention exceptionally dry air. that green in the east pacific needs to be over the tropical atlantic.

But did not Chantal run into the same atmospheric conditions, dry air, as the one coming off Africa? Chantal persevered. I know it is too early to tell.

[gatorcane]

Latest SAT image shows plenty of moisture associated with pouch 12L near the African coast:

[ninel conde]

here is the clear reason the wave will die.

http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... hour=096hr

it will run into incredibly high pressure, not to mention exceptionally dry air. that green in the east pacific needs to be over the tropical atlantic.

But did not Chantal run into the same atmospheric conditions, dry air, as the one coming off Africa? Chantal persevered. I know it is too early to tell.

i dont think you need to worry about the wave at all but check in with the NHC from time to time.

[sunnyday]

As Shakespeare said, "Much Ado about Nothing."

[ozonepete]

here is the clear reason the wave will die.

http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... hour=096hr

it will run into incredibly high pressure, not to mention exceptionally dry air. that green in the east pacific needs to be over the tropical atlantic.

Don't know where you got the notion that an easterly wave or TC "running into incredibly high pressure" is a reason for demise. These storms do not run into high pressure, they move along the edges of them driven by complex steering processes, primarily at the mid-levels of the atmosphere. In this case the wave will run along the southern edge of this large Bermuda High like all of them do out there. If a break, or weakness develops in the ridge it will turn right. But they never run into a high or through it, nor do they get dissipated by it. Many of the most intense hurricanes that made landfall in the U.S. went along the southern edge of very strong high pressure like this, intensifying as they went. Isabel of 2003 is one of many examples. As far as the dry air, that is not exceptionally dry air. It is average for this time of year and is what we call marginal for development. I think everyone is expecting too much from these waves yet - it's still early.