2012 Long Range Model Discusssion (> 7 Days Out)

[Michael Snyder]

Know how I know you havent seen Animal house?

 

[Mark Blue]

Has anybody noticed that the GFS is wanting to continue an abnormally strong subtropical jet and develop another upper low down there starting around the 180 hour range and on past that? I think this is the issue we're still running into. We're getting a low developing down there which shunts the northern troughing even further north, keeping northern Mexico and southern Texas in play but ridging out the Central Plains. Maybe this is the opposite of that and the fact that the polar troughing is staying so far north is leading to the development of the low, but it's something to look at. Every time this Mexico 500mb low goes away on the GFS runs, we get a massive dooms day trough kicking straight through the plains.

Back to the subject at hand, yes, I've looked at the models today (ECMWF, NOGAPS, and GFS) and depending on whether it's the 0Z or 12Z run it looks consistent from run to run (there are a few variances), but I'd say that it's going to be a quiet pattern until at least next weekend -- at least 2 days beyond the 18th, which was the original date we were hoping for earlier this week. It seems like we're in a persistent pattern right now that isn't going to change anytime soon, but we are talking long range models so anything can happen as we all know, with sneaky surprises from day to day. It's interesting to look at the enhanced water vapor loop from a CONUS perspective to see the family of cyclones traversing Canada along the northern branch of the jet stream, while the same thing is happening along the southern branch in northern Mexico and the southern states where compact and/or closed lows are cruising along, but then becoming open (weaker) waves as they move into the lower Mississippi river valley along the Gulf states. All I can say is I'm glad we didn't lock in any chasecations this year and are flexible to do as we please!

 

[Cstok]

I am becoming to be a LITTLE more optomistic for next weekend 5/19/12:
Thinking: The 5/13/12 12z GFS is suggesting some sort of trough off central Cal 5/19/12/ 12z. ECMWF also showing this feature for 5/19/12 as of 5/13 0z run. Also see the NCEP ensamble spag map suggesting this as well (perhaps a bit more zonal).
Concerns: Moisture is going to be an issue as no significant feature to transport GOM far enough north in to N KS / NE, which is where I think there might be just enough upper level support, and if there is any action that is where it would be. Also CAP may be too robust to be overcome as the 500mb temps are of concern.

Go easy on me.... I am still a newb as far as long range forecasting goes... but I want to find something to try to get excited about.

 

[Dan Robinson]

Looking at the past few runs of the long ranges, culminating with the latest 12z, I'd say there is an 85% chance that May is done. I'm not impressed with the system that manages to squeak some flow by the extreme north before a mega-ridge builds in afterward. It won't have a mixing-resistant moisture layer to work with. Furthermore, such a dominant ridge will be hard to break down, possibly even into June. The season does look uncannily like 2006. Of course, things can change, but I'm not optimistic.

If I had a chase vacation now, I'd consider heading to the Florida Keys for waterspouts and lightning. I think that would turn out better than whatever happens in ND/MN later this week.

 

[Bob Hartig]

I've been watching May 18-19 long enough now to think two things:
1. A trough is going to move through the northern plains, but
2. any meaningful UA support will likely be north of and/or west of deep moisture.

If I've seen any kind of consistency in the long-range models, the above two points cover it, and the bottom line is, a drive to North Dakota probably isn't in the cards for me. But who knows. No need to get definitive just yet; I'm curious to see what happens over the course of this week.

 

[Michael Snyder]

GFS starting to look a bit more optimistic for end of May.
Remember how quick things change before giving up....

 

[Joshua Nall]

I don’t remember making a trip to the plains in June. Chasing is usually over for me the end of May due mainly to summer time work getting hectic. Never been north of Kansas. Taking even a two day trip to Nebraska just never seemed doable. But since May has been quite, taking a week off and picking an active period in June to hit the high plains sounds exciting. I would love to see some new country, and hopefully some storms I can keep up with …. The grass will be here when I get back, just twice as high… lol.

 

[Matthew Crowther]

This could be the first year since I began this avocation in 1989 that I do not chase even one day in May. The new 00Z GFS is about as bad as it gets.

 

[Andrea Griffa]

After I have seen all the GFS crapcast for the long range, the 8-14 precipitation probability outlook, the SPC outlook for day 4-8 and each other map on this Earth it looks like there's no hope anymore.

Anyway, the only thing that comes to my mind is that it is not so probable that we don't see anything by may 24 after 3 weeks of ridge. I mean ECMWF is forecasting a through coming down for May 24, and I trust more ECMWF than GFS as regards the long range. Let's see.

http://www.ecmwf.int/products/forec...op!od!oper!public_plots!2012051400!!chart.gif

 

[Clarence Bennett]

Once in about every four runs the gfs and ec both throw us a bone. The other three are just junk and spell doom as far as any active weather is concerned. Even with the little northern waves being depicted, I think there are other issues with moisture return, placement of upper energy, etc. In the long range, it is pattern recognition and I have very low confidence in what I am seeing in day to day runs. The GFS has been pretty descent within 144hrs, so lets see how it handles things around the 19th since we are now within that window. My departure date is scheduled to be the 19th, so I am biting my nails along with everyone else with trips planned.

 

[Adam Adkins]

I am trying to be optimistic about the last week or so of May through June. Colorado's severe weather season peaks in June, so assuming the pattern changes by then, and I believe it very likely will, eastern CO will have a lot to offer from the end of May on. Before then, both the 00 and 06 GFS look... pretty bad. But I do again have hope for MAYBE this weekend only marginally in E CO. It seems based on past SVR events here that it doesn't require an official trough rolling through to make that happen. The GFS has increased low level moisture, increased CAPE, and slightly increased shear for next weekend... while low levels are lacking it my wind up marginal east of the front range.

 

[Jesse Risley]

If you're looking for a major synoptic trigger, such as a deep trough, then you might be disappointed for the next 10+ days. However, the absence of a significant trough like that which came to fruition in mid-April doesn't necessarily mean there will be no favorable setups for chasers.

There are always upslope setups east of the Rockies (someone noted the CO severe season in a previous post), and other mid-level perturbations, if juxtaposed with adequate ingredients such as favorable moisture, instability and at least marginally adequate wind shear, can yield some surprisingly rewarding days that will not be discernible on the models this far in advance.

 

[Kelly Sugden]

I pretty much agree with everything that has been said already. The GFS is trending slower and weaker to the ECMWF solution. I see this day in and day out with the GFS being too progressive/aggressive with dynamics aloft and moisture in the boundary layer. This model cannot be trusted. It really is garbage, all 384 hours of it. Use the EC/EC ensembles for forecasting in the long range and you will probably verify better. Again, there is a reason why the ECMWF takes so long to come in and that is due to post processing (i.e. better physics).

There probably will be a low end severe event across the northern Plains towards the end of this week/into the weekend but nothing to write home about... maybe a decent photography session. For how busy the last couple of Mays have been maybe its only fair that this May will be quiescent. I know the general public would like it... despite what some storm chasers think.

K.

 

[Jeff Duda]

Anyway, the only thing that comes to my mind is that it is not so probable that we don't see anything by may 24 after 3 weeks of ridge. I mean ECMWF is forecasting a through coming down for May 24, and I trust more ECMWF than GFS as regards the long range. Let's see.

http://www.ecmwf.int/products/forec...op!od!oper!public_plots!2012051400!!chart.gif

Been seeing a lot of those in the various models (including ECMWF) over the past week. Already acquiring negative tilt at hour 240. Any shred of energy probably won't make it south of I-80. System will probably get picked up in the aggressive zonal pattern and get swept across the far northern CONUS and southern Canada by the next run.

Yes, that's my "optimism" speaking. Like Mr. Crowther, it's starting to look pretty likely I will go through a May without a single chase.

 

[Andrea Griffa]

Could easily be, Jeff..As matter of facts, 3-4 days ago ECMWF was forecasting an "higher" solution in terms of position of the trough such as GFS. By yesterday both GFS and ECMWF are starting to mention this impulse coming down a little bit. Now, the important is to have at least a little dynamism in the long range.

Been seeing a lot of those in the various models (including ECMWF) over the past week. Already acquiring negative tilt at hour 240. Any shred of energy probably won't make it south of I-80. System will probably get picked up in the aggressive zonal pattern and get swept across the far northern CONUS and southern Canada by the next run.

Yes, that's my "optimism" speaking. Like Mr. Crowther, it's starting to look pretty likely I will go through a May without a single chase.