ATL : TROPICAL DEPRESSION ALEX - MODELS

[Nederlander]

do you guys think that alex will pass far enough east of me that we dont get any rain from him here in SA?

As I have told you. WAIT.. none of us know where Alex is headed.. you may get some moisture from Alex if it tracks more towards texas.. but asking where Alex is going every hour isnt going to change the fact that we simply dont know at this point...

[Nederlander]

The question that I would like to ask is this: does the Euro typically over do ridges... and/or does the gfs/cmc tend to show weaker ridges than what verifies?

[gatorcane]

The question that I would like to ask is this: does the Euro typically over do ridges... and/or does the gfs/cmc tend to show weaker ridges than what verifies?

The ECMWF/UKMET do tend to overdo ridges, so I have been told. If the ECMWF/UKMET get the track right this time, with the GFS/CMC/HWRF showing a much different solution, there will likely be more ECMWF-huggers out there for the next systems that develop in the Atlantic. I have to say though, for long-range steering, it seems the ECMWF gets things right more than the GFS.

[dixiebreeze]

The mighty trough: http://www.ssd.noaa.gov/goes/east/eaus/flash-wv.html

[Vortex]

IMO, I think there stands a better than resonable chance that Alex attains Major Hurricane Status at some point. The environmental factors will be nearly ideal for strengthening and even a period of rapid intensification seems likely once Alex pulls away from the Yucatan Peninsula.. After analyzing/reviewing the current and forecasted synoptic set-up those residents along the entire Texas coastline should be going over their Hurricane Preparedeness "checklist" this evening as I suspect that significant changes in the forecasted path of Alex are pending..

[ROCK]

did the CMC just run again? 18z?
http://www.sfwmd.gov/portal/page/portal ... el%20plots

[vaffie]

did the CMC just run again? 18z?

Not yet, another hour or so before it runs.

[ROCK]

I didnt think the CMC ran 18z or 6z......hmmm...shows what I know....

[vaffie]

I didnt think the CMC ran 18z or 6z......hmmm...shows what I know....

I think the 6Z and 18Z tracks are just computer-calculated continuations of the 0Z and 12Z tracks. I don't think it really re-runs the whole model. That's why it still has a bizarre east then west loop near landfall as the 12Z run did.

[chzzdekr81]

Here's what I don't understand. I was checking out the spaghetti models at StormPulse.Com and almost all of the models showed Alex going north into the Texas coast. However, the track still shows Alex making its second landfall in Mexico. What's up with that?

[ConvergenceZone]

A bit off topic, but I figure this is the best place to ask. Does anyone have a link to a site that explains how models get their data? I find it fascinating that different models forecast different outcomes sometimes. They must be pulling different data somehow? Is there a website out there that helps explains what data inputa model looks at? This is very fascinating to me.

Thanks!

[ROCK]

Here's what I don't understand. I was checking out the spaghetti models at StormPulse.Com and almost all of the models showed Alex going north into the Texas coast. However, the track still shows Alex making its second landfall in Mexico. What's up with that?

NHC is weighing the EURO/UKMET/NOGAPS over the GFS, CMC and to some extent the GFDL and HWRF....you have 2 camps of models....NHC they have a below average confidence right now because of it...

[KWT]

IMO, I think there stands a better than resonable chance that Alex attains Major Hurricane Status at some point. The environmental factors will be nearly ideal for strengthening and even a period of rapid intensification seems likely once Alex pulls away from the Yucatan Peninsula.. After analyzing/reviewing the current and forecasted synoptic set-up those residents along the entire Texas coastline should be going over their Hurricane Preparedeness "checklist" this evening as I suspect that significant changes in the forecasted path of Alex are pending..

Yeah, the models do show a pretty potent set-up aloft, and the Gulf is very warm at the moment so I see no reason why this can't at least get into the 80-90kts range, after that who knows...

As for the UKMO/ECM, they do indeed from what I've observed sometimes display a over-pumping of subtropical ridges and aren't quite progressive enough...then again the GFS/CMC tend to be the other way round, so its balancing it out really.

[tolakram]

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.

Here's how I see it. The Canadian had the best short term tracking last year, so let's see what Alex does in the next day. If it shoots north then we know it verified. The Euro seems to have a better handle on medium term features, which means the ridge will probably build back in and force Alex to turn back to the west.

We'll have to see of course, but that's what I'm looking for. If Alex does start out going north it's going to make a whole lot of people really nervous! Darn these storms and their penchant for not traveling in a straight line!

[vaffie]

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.

It is remarkable how well it kept its core together while over the Yucatan. The spiral band just to the north of the center is quickly forming convection with cooling cloudtops as observed in just the past 15 minutes. It's core will be complete again at this rate by 2 am, and I agree that it could be up to a hurricane again by the middle of tomorrow, potentially even a major hurricane by Tuesday morning. It is very concerning for SE Texas, with the usually-west-biased EURO and UKMET models pointing to our south but with each run shifting northward. And we now have almost 30 hours of consistent GFS/CMC and increasingly GFDL/HWRF pointing towards the Texas coast. I would recommend everyone on the Texas and western Louisiana coasts to be preparing right now as if it really will hit your area.

[LaBreeze]

Hmmm a strange presentation from the NAM with it seemingly trying to possibly develop something NE of the system in that convective stuff...looks like its totally out of it, as you'd somewhat expect.

Actally KWT, this is what the GFS has been showing the last several runs. Not saying the GFS is not out to lunch too. We do have alot of convective activity in the northern gulf well detached from the circulation. The GFS forecasts vorticity to spark up from that activity and weaken the ridge.

I live in SE Texas and we are getting activity (thunderstorms) now. Not sure if this is related to Alex.

Same here along the SW LA coast - tropical showers and thunder, very humid (of course, that's what we usually have on a summer day). Wondering the same

[ROCK]

18z GFS running. ....here we go!!

[Ikester]

I think it is important for this paragraph from the 4am update June 27th to be reposted:

THE MOTION ESTIMATE IS 300/10. THE SHORT TERM MOTION IS THE ONLY
THING STRAIGHT-FORWARD ABOUT THE FORECAST TRACK. ALL OF THE MODELS
AGREE ON AN UPPER-LEVEL LOW CURRENTLY JUST EAST OF HUDSON BAY
CANADA TO DIG SOUTHWARD AND CARVE OUT A DEEP TROUGH OVER MUCH OF
THE EASTERN U.S. DURING THE NEXT 5 DAYS. AS THE TROUGH AMPLIFIES
...THE SUBTROPICAL RIDGE CURRENTLY SITUATED ACROSS FLORIDA AND THE
NORTHERN GULF OF MEXICO ERODES IN THE 36-72 HOUR TIME FRAME LEAVING
A LARGE WEAKNESS IN THE RIDGE OVER THE CENTRAL AND WESTERN GULF.
THIS WEAK FLOW PATTERN IS EXPECTED TO CAUSE ALEX TO SLOW DOWN AND
ALLOW THE CYCLONE TO GAIN SOME LATITUDE. AFTER THAT...HOWEVER...THE
MODELS DIVERGE SIGNIFICANTLY WITH THE GFS AND CANADIAN MODELS
TAKING ALEX NORTHWARD THROUGH THE WEAKNESS IN THE RIDGE TO THE
TEXAS-LOUISIANA BORDER AREA...WHEREAS THE ECMWF...NOGAPS...GFDL...
HWRF...UKMET...AND GFS-PARALLEL MODELS MOVE ALEX WESTWARD INTO
NORTHEASTERN MEXICO. THE MAIN DIFFERENCE IN THE MODELS IS HOW THEY
HANDLE THE MID-LATITUDE TROUGH-RIDGE PATTERN. THE GFS AND CANADIAN
MODELS ARE MORE PROGRESSIVE AND LESS AMPLIFIED WITH THE FLOW
PATTERN ACROSS THE NORTHERN U.S. DURING THE FORECAST PERIOD...
WHEREAS THE OTHER MODELS PRODUCE A STRONGER...MORE HIGHLY AMPLIFIED
...AND SLOWER PATTERN. THE CURRENT PROGRESSIVE 5-WAVE NORTHERN
HEMISPHERIC FLOW PATTERN WOULD TEND TO FAVOR THE THE GFS-CANADIAN
SOLUTION...BUT AT LEAST ONE MORE MODEL CYCLE WILL BE REQUIRED TO
CONFIRM THAT TREND. THE OFFICIAL FORECAST TRACK IS TO THE RIGHT OF
AND SLOWER THAN THE PREVIOUS ADVISORY...AND IS SIMILAR TO THE
CONSENSUS MODEL...TVCN. [b]NOTE...IF THE RECENT NORTHWARD SHIFT IN THE
MODELS CONTINUES...THEN ALEX COULD REMAIN OVER WATER FOR THE NEXT 5
DAYS RESULTING IN A VERY POWERFUL HURRICANE.[/b]

[ROCK]

[Wx_Warrior]

GFS 18z 30H

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