ATL: TROPICAL DEPRESSION ALEX - DISCUSSION

[Frank2]

I didn't realize this was already approaching CA and soon inland...

Per the latest TWO, it's like someone trying to make a full pitcher of lemonaid with one lemon (lol)...

Frank

[Ntxwx]

Developing TD with the low pressure system South-Southwest of JAM. Here we go.. Now lets see if the shear can hold off, and sustain convection until more LLC is detected.

[KWT]

Most of the models seem to keep this area weak until after it, or as it crosses the Yucatan. It is starting to tighten a bit. More waiting. Didn't wxman say something about Friday or Saturday.

The low level feature that the NHC are tracking may struggle to even get int othe BoC...though it'll probably make it into the southern section where land effects may help past say 48-72hrs...

Its a nonsense to be honest though, if they are tracking this region then chances of development should be between near 0 and 10% because that ghost system that Hurakan mentioned will not develop in the next 48hrs I'm pretty certain of that. Instead watch the second wave, thats the one that has a shot at development, this ghost system will not develop for a good 72hrs I'm pretty confident.

[Frank2]

Developing TD with the low pressure system South-Southwest of JAM. Here we go.. Now lets see if the shear can hold off, and sustain convection until more LLC is detected.

Didn't you read the latest TWO - nothing like that even considered by the NHC at this time, since "over the next couple of days" would place the wave inland over Central America...

Frank

[HURAKAN]

93L has what 92L lacked (good environment) and 93L lacks what 92L had (well-defined LLC). Serves as a reminder that we live in an unfair world!!! lol

[clfenwi]

18Z came early today

AL, 93, 2010062418, , BEST, 0, 165N, 815W, 25, 1008, WV, 34, NEQ

[KWT]

That low level circulation is tightening as it gets closer to land, probably the land friciton coming into play again...

Problem is it is more or less a naked swirl with 12-18hrs before it heads inland...as I said I'd personally place chances of that region developing closer to 0% than 40...its the eastern flank of the broad low that needs to be watched but even that may not do anything because the tightening of the doomed low!

[tailgater]

A TROPICAL WAVE EXTENDS FROM 24N81W ACROSS WESTERN CUBA TO NEAR
13N80W. VISIBLE SATELLITE IMAGERY INDICATES THE BEGINNINGS OF A
BROAD SURFACE CENTER...MANIFESTED IN A 1009 MB LOW CENTERED
ROUGHLY NEAR 16N82W. THE LOW CENTER EXTENDS SURFACE TROUGHING
SOUTHWARD TO THE GULF OF MOSQUITOS AND ALSO NORTH-NORTHWESTWARD
TO THE GULF OF HONDURAS. ORGANIZED DEEP CONVECTION LACKS WITH
THIS SYSTEM AT THIS TIME...HOWEVER SCATTERED MODERATE AND
ISOLATED STRONG CONVECTION ASSOCIATED WITH THE NORTHWARD EXTENT
OF THE TROPICAL WAVE ARE OCCURRING FROM 13N-21N BETWEEN 74W AND
THE WAVE AXIS ALONG 81W. SCATTERED SHOWERS AND ISOLATED MODERATE
CONVECTION ARE FROM 11N-22N BETWEEN THE WAVE AXIS ALONG 81W AND
88W. ANOTHER AREA OF SCATTERED MODERATE CONVECTION IS OVER THE
STRAITS OF FLORIDA FROM 22N-25N BETWEEN 77W-82W. UPPER-LEVEL
WINDS ARE FORECAST TO BECOME MORE CONDUCIVE FOR DEVELOPMENT OF
THIS SYSTEM AS IT MOVES WESTWARD OR WEST-NORTHWESTWARD OVER THE
NEXT COUPLE OF DAYS.

[Ntxwx]

A TROPICAL WAVE EXTENDS FROM 24N81W ACROSS WESTERN CUBA TO NEAR
13N80W. VISIBLE SATELLITE IMAGERY INDICATES THE BEGINNINGS OF A
BROAD SURFACE CENTER...MANIFESTED IN A 1009 MB LOW CENTERED
ROUGHLY NEAR 16N82W. THE LOW CENTER EXTENDS SURFACE TROUGHING
SOUTHWARD TO THE GULF OF MOSQUITOS AND ALSO NORTH-NORTHWESTWARD
TO THE GULF OF HONDURAS. ORGANIZED DEEP CONVECTION LACKS WITH
THIS SYSTEM AT THIS TIME...HOWEVER SCATTERED MODERATE AND
ISOLATED STRONG CONVECTION ASSOCIATED WITH THE NORTHWARD EXTENT
OF THE TROPICAL WAVE ARE OCCURRING FROM 13N-21N BETWEEN 74W AND
THE WAVE AXIS ALONG 81W. SCATTERED SHOWERS AND ISOLATED MODERATE
CONVECTION ARE FROM 11N-22N BETWEEN THE WAVE AXIS ALONG 81W AND
88W. ANOTHER AREA OF SCATTERED MODERATE CONVECTION IS OVER THE
STRAITS OF FLORIDA FROM 22N-25N BETWEEN 77W-82W. UPPER-LEVEL
WINDS ARE FORECAST TO BECOME MORE CONDUCIVE FOR DEVELOPMENT OF
THIS SYSTEM AS IT MOVES WESTWARD OR WEST-NORTHWESTWARD OVER THE
NEXT COUPLE OF DAYS.

Thank you.

[KWT]

Good to see that a surface center is forming with that region, probably means the odds of development with this now are very low (I know its backward logic...) still I think we've seen a classic land tightening event occuring here with the LLC. I think its probably close to being closed.

This is because this area has very poor instablity aloft hence the reason why it can't create storms, plus the fact its going to be inland in about 12-18hrs at this rate *unless* it forms its center far enough east but I think due to land friction it'll form close to land. If a surface low didn't form I feel there would have been a decnt chance that once the first wave went overland the 2nd wave would become dominant, now the first wave does have a circulation, it probably means the 2nd one will struggle.

ps, that being said obviously if it followed the GFDL track and swang north-westwards in the next 24hrs, then of course its going to have a chance BUT it has to see a change in the upper conditions first.

[tailgater]

Good to see that a surface center is forming with that region, probably means the odds of development with this now are very low (I know its backward logic...)

This is because this area has very poor instablity aloft hence the reason why it can't create storms, plus the fact its going to be inland in about 12-18hrs at this rate *unless* it forms its center far enough east but I think due to land friction it'll form close to land. If a surface low didn't form I feel there would have been a decnt chance that once the first wave went overland the 2nd wave would become dominant, now the first wave does have a circulation, it probably means the 2nd one will struggle.

Hope your right! bouy 42057 almost a 3 mb drop over 24hrs. axis must be almost due south.
Wind Direction (WDIR): E ( 90 deg true )
Wind Speed (WSPD): 5.0 m/s
Wind Gust (GST): 5.0 m/s
Wave Height (WVHT): 1.6 m
Dominant Wave Period (DPD): 8 sec
Average Period (APD): 5.7 sec
Atmospheric Pressure (PRES): 1008.7 mb
Pressure Tendency (PTDY): -0.7 mb ( Falling )

[Ivanhater]

[x-y-no]

Yes, the surface low associated with the wave axis at 81W is getting much more obvious. But that wave is out of time in my opinion. It'll be running into Honduras tonight and that'll be that, unless it develops down the road in the EPAC.

On the other hand, the convective blob south of Haiti has been flaring up very impressively during the last few hours. And as mentioned in the TWD, there's another wave approaching the area:

TROPICAL WAVE IS ALONG 71W S OF 20N MOVING W-NW NEAR 10-15 KT.
THE WAVE REMAINS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYER
MOISTURE THAT COVERS THE ENTIRE CARIBBEAN AS INDICATED ON TOTAL
PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE TO STRONG
CONVECTION IS FROM 14-18N BETWEEN 65W-74W. ENERGY SHEARED OFF
THE NORTHERN EXTENT OF THE WAVE IS RESULTING IN SCATTERED
MODERATE CONVECTION FROM 16N-19N BETWEEN 56W-65W.

It's a pretty weak wave, but I'm thinking these two features can reinforce each other and we may well get something going pretty quickly there. Unlike the wave at 81W, this area has both strong surface convergence and fair upper-level divergence.

If something does manage to spin up there, it faces an immediate problem with the strong shear over the islands. If, as seems likely, it moves more or less northwesterly it's likely to get torn up pretty quickly, first by shear, then by interaction with Cuba.

N.B. :

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[KWT]

It all depends x-y-no if the system gets lifted out liken the GFDL and quite a few other models are suggesting the whole lot will lift NW soon.

The other thing I'll say is the convection in the east could well promote a tighter LLC if the system does end up heading inland soon. Still no doubt there is a broad low there now though.

[x-y-no]

I don't see the western wave lifting NW unless it deepens - and it's shown absolutely no hint of doing so yet.

If it stays a naked surface swirl, it seems to me it will keep moving west straight into CA.

[Ivanhater]

Hmm..not looking at the low by central america

[Sanibel]

We should see this improved IR trend continue if the lower level swirl stays over water. What it does from there is anybody's guess.

[Air Force Met]

It all depends x-y-no if the system gets lifted out liken the GFDL and quite a few other models are suggesting the whole lot will lift NW soon.

The other thing I'll say is the convection in the east could well promote a tighter LLC if the system does end up heading inland soon. Still no doubt there is a broad low there now though.

I think to many on here are way to quick to dismiss oppr old 93L. I disagree with x-y-no on it running out of time. I think what is happening is a secondary impulse is moving into the backside of the wave and we see that result in the form of the deep convection exploding south of Hisp. There is a surge of low level easterlies pressing into the wave axis and this is the cause of the convection...and why the wave axis is starting to tilt more towards the NE (insted of N-S).

If you look at the hi-res vis loops and watch the actual broad low...you can see that it is slowely becoming less round and more egg shaped...leaning NE-SW. What is happening is the low level cu field is responding to the lowering pressures in the area...

I give this more than a 50/50 chance...more like a 70% chance of forming...probably by tomorrow night. I don't think the trof will catch it...and believe that somewhere along the lower TX coast or N Mexico is the eventual destination. What could also happen is the GFS is more right than I am giving it credit...and future Alex moves into the north or central Gulf...stalls...then heads to the west as the ridge builds in.

There...that's my 2 cents...for what it is worth...

[KWT]

I think steering currents will probably weaken with the western wave though x-y-no and if that does then I can only assume the better convergence zone will continue west to the point where this low can take advantage and then lift NW.

Ivanhater...hmmm VERY interesting, looks like they are more convinced about the MLC south of Jamiaca right now.

Well at least there is plenty to talk about!

Haha AFM says what I said so much better than I ever could haha!

[Sanibel]

I'm thinking the deeper convection is shear-displaced and part of the Honduras low level swirl. It's enhanced by the tropical flow piling it up against the synoptic to its north.