ATL : TROPICAL DEPRESSION ALEX - MODELS

[Blown Away]

Looks like no big change for the 12z:
AL, 93, 2010062312, , BEST, 0, 156N, 766W, 25, 1010,

Goes to show how much I know!
Their graphic is a little confusing because this location would be at the extreme SW corner and the graphic is centered over the blob S of Haiti??
http://www.nhc.noaa.gov/

[gatorcane]

12Z UKMET shows nothing at 120 hours:

[littlevince]

Comparison of the last 8 outputs from ECMWF, oldest to newest





Some EPS (ECMWF Ensemble) outputs for 1 July


EPS Mean SLP and deviation:



Last operational SLP output and deviation:

[Dean4Storms]

I am 100% sure this is NOT a Florida system even if it develops.

Pro Mets would rarely say 100% with anything.. Timing can change everything and we don't even have a LLC yet...... You can go ahead and beat your chest being the all knowing forecaster but..whatever.

I agree, the FLORIDA panhandle is certainly not out of the woods and even the west coast of peninsula Florida and the Keys have a small chance still.

[bvigal]

Gave up worrying about the fix location, after 24hrs of surface maps denoting a future low (22Jun 06z) resulted in nothing on the map after 24hrs (23Jun 06z). What was evident is plenty of moisture, conditions conducive to development, and possibility of movement into the GOM, i.e. exact timing/fix maybe less important than the insistance of models the last 24hrs. We'll have to take these models with a grain of salt until there is at least a surface low to fix.
Latest look at wv loop, the blob just SE of Haiti is building, while the others seem to be waning, which supports the 8am upgrade to 30% and the 12z fix. The models might look more plausible later today or tonight.

[mf_dolphin]

Gave up worrying about the fix location, after 24hrs of surface maps denoting a future low (22Jun 06z) resulted in nothing on the map after 24hrs (23Jun 06z). What was evident is plenty of moisture, conditions conducive to development, and possibility of movement into the GOM, i.e. exact timing/fix maybe less important than the insistance of models the last 24hrs. We'll have to take these models with a grain of salt until there is at least a surface low to fix.
Latest look at wv loop, the blob just SE of Haiti is building, while the others seem to be waning, which supports the 8am upgrade to 30% and the 12z fix. The models might look more plausible later today or tonight.

Couldn't agree more! Until we have a real LLC the models just give an idea of overall scenarios.

[Dean4Storms]

Convection would have to get going today south of Jamaica for these models runs to begin to look verifiable and a surface low beginning to close off and as of now that does not look likely.

[Frank2]

Exactly - just giving ourselves a tylenol headache for nothing at this point (lol), because the models will turn out as many scenarios as they can, based on the current weak system...

It's still a very disorganized area with a long way to go, so we'll see what happens in the next 48-72 hours - one way or the other...

Frank

[gatorcane]

Convection would have to get going today south of Jamaica for these models runs to begin to look verifiable and a surface low beginning to close off and as of now that does not look likely.

How about the GFS? Not only did that model perform excellent for 92L but it is so far nailing the forecast for 93L. Recall that even several days ago it called for convection to develop and spread out over the northern and eastern caribbean with no organized low at this point. That is exactly what we are seeing.

GFS in no run so far has shown 93L to be any more than a sheared tropical storm, and most runs is just a vigorous tropical wave heading towards the Yucatan with attached low.

To be honest I am quite alarmed at the inconsistency with the ECMWF and some of the other models like CMC.

[clfenwi]

A little cross-posting...from this morning's discussion on E-Pac Tropical Storm Darby:

...THE FORECAST TRACK OF DARBY
HINGES HEAVILY UPON WHAT HAPPENS TO THE DISTURBANCE LOCATED OVER
THE CENTRAL CARIBBEAN SEA. THE GFDL AND HWRF MODELS...PLUS ALL OF
THE GLOBAL MODELS EXCEPT FOR THE GFS...DEVELOP THE CARIBBEAN
DISTURBANCE TO VARIOUS DEGREES OVER THE NEXT 5 DAYS...WHICH CAUSES
THE SUBTROPICAL RIDGE TO THE NORTH OF DARBY TO WEAKEN BY DAYS 3-4.
THIS RESULTS IN A WEAKENING OF THE STEERING FLOW...AND SOME OF THE
MODELS EVEN FORECAST SOME WEAK BINARY INTERACTION WITH THE
DEVELOPING CARIBBEAN DISTURBANCE AFTER THAT SYSTEM ENTERS THE
SOUTHERN GULF MEXICO. THE GFS DOES NOT SHOW ANY INTERACTION WITH
THE CARIBBEAN DISTURBANCE BECAUSE IT NEITHER DEVELOPS DARBY OR THE
OTHER SYSTEM. DUE TO THE POOR 06Z INITIALIZATION AND SHORT TERM
FORECAST TRENDS BY THE GFS MODEL...LESS WEIGHT HAS BEEN PLACED ON
THAT MODEL AND IT IS CONSIDERED AN OUTLIER. THE OFFICIAL FORECAST
MAINTAINS THE PREVIOUS FORECAST TREND OF SLOWING DOWN DARBY IN THE
72-120 HOUR TIME FRAME DUE TO EXPECTED INTERACTION WITH THE LARGE
CARIBBEAN SYSTEM...REGARDLESS OF WHETHER OR NOT THAT SYSTEM GOES ON
TO BECOME A TROPICAL CYCLONE.

[HouTXmetro]

Can someone explain the difference in the TVCN and AEMN computer models? Are any of those two usually reliable?

[clfenwi]

Can someone explain the difference in the TVCN and AEMN computer models? Are any of those two usually reliable?

TVCN is the consensus of whatever's available from GFDL, UKMET, NOGAPS, HWRF, GFS, GFDN, and the European model. It's good when there's a developed storm and there's output from most all of those models. However, in a situation like this it can be iffy, because you aren't getting tracks from all of those and if there's one outlier/busted run in the group then the consensus is thrown out of whack fairly seriously.

AEMN is the GFS Ensemble. I don't have any comments to offer on its performance with developing systems.

Source:Technical Summary of the National Hurricane Center Track and Intensity Models

[HouTXmetro]

Can someone explain the difference in the TVCN and AEMN computer models? Are any of those two usually reliable?

TVCN is the consensus of whatever's available from GFDL, UKMET, NOGAPS, HWRF, GFS, GFDN, and the European model. It's good when there's a developed storm and there's output from most all of those models. However, in a situation like this it can be iffy, because you aren't getting tracks from all of those and if there's one outlier/busted run in the group then the consensus is thrown out of whack fairly seriously.

AEMN is the GFS Ensemble. I don't have any comments to offer on its performance with developing systems.

Source:Technical Summary of the National Hurricane Center Track and Intensity Models

THANKS!

[TreasureIslandFLGal]

The inevitable center relocation and the slow steering currents will make this one a very tough call late in the forecast period. You can never trust the movement of a very slow moving gulf system. They often loop and do wacky things. Saying that Florida is in the clear this far out isn't a prudent call Gatorcane. How many slow moving (<6kts) gulf systems have defied the early models? Plus, with a slow down, this may not impact any land directly for 7+ days. I'm sure that ridge will wiggle around by then...either to nudge the system to the left or pull back and allow a more easterly path. heck, it might build west significantly and force a would-be Alex southwestward into S. Texas or NE Mexico! The bottom line...everyone along the gulf coast needs to keep watch and make sure their preps are in order.

One of the worst scenarios that will likely pan out from this, is that the rigs will need to be evacuated and the oild will free flow into the gulf with no sidpersants for as long as Alex poses a threat. -which could be a long time. And if it is a significant storm, a lot of oil is going ashore somewhere. That would/will make a horrible coastal storm even more devastating if it throws oil onto the shore and marshes...and much deeper inland than it would normally flow, due to storm surge. ugh, how depressing! (Of course, BP could say that any such damage was "act of God" so they don't have to cover that...jsut what would be "normal" expected oil impact sans storm influence.

[CrazyC83]

If the storm slowed down in the northern Gulf though this early in the season, I would think it would weaken quite a bit...but be catastrophic for the oil spill...

[gatorcane]

12Z GFS rolling out, looks like 93L is getting buried in the Yucatan again with no development. Large ridge over the GOM and Southern US to the north...same thing the GFS has been showing for the past several runs over the past couple of days. I expect the ECMWF to come on board in the next few runs.

It's also showing a good amount of SW shear in the GOM (Northern and Western GOM) at 66 hours out which is not good for any significant development. A large anticyclone appears to develop in the SE GOM.

Great news.

[Stormcenter]

Excellent news.....we don't need anything tropical anywhere in the GOM
right now (or ever)with the oil spill crisis going on.

12Z GFS rolling out, looks like 93L is getting buried in the Yucatan again with no development. Large ridge over the GOM and Southern US to the north...same thing the GFS has been showing for the past several runs over the past couple of days. I expect the ECMWF to come on board in the next few runs.

It's also showing a good amount of SW shear in the GOM (Northern and Western GOM) at 66 hours out which is not good for any significant development. A large anticyclone appears to develop in the SE GOM.

Great news.

[CourierPR]

12Z GFS rolling out, looks like 93L is getting buried in the Yucatan again with no development. Large ridge over the GOM and Southern US to the north...same thing the GFS has been showing for the past several runs over the past couple of days. I expect the ECMWF to come on board in the next few runs.

It's also showing a good amount of SW shear in the GOM (Northern and Western GOM) at 66 hours out which is not good for any significant development. A large anticyclone appears to develop in the SE GOM.

Great news.

The NHC discussion on Darby includes a mention of the developing system in the Caribbean and characterizes the GFS solution as an outlier. Way too early for anyone to be sounding an ALL CLEAR!

[cycloneye]

GFS needs the upgrade,it doesn't have Tropical Storm Darby.

[Comanche]

I need a Patience 2.0 upgrade!