May Chasing 2008

[Mark Farnik]

All I can say in regards to the potential of the active pattern later this month is two things:
- the storm activity really needs to make a major northward shift. I know this has been a great setup this spring for Southern Plains chasers, but its time for the Central and Northern Plains to get in on the act. I'm sick of the prospect of 1500+ mile chases. How about a nice eastern CO/western KS and NE tornadic setup for a change, not counting the April 24th northwest KS storm?

- there had better damn well NOT be a major outbreak on the 23rd or 24th... the 24th is the day of my high school graduation, and that's something I can't miss, seeing as I'm speaking and singing at it, along with hosting 150 + guests at a grad party afterwards, which I have to help my parents prepare for the night before.
If there's going to be a huge chase day, it can either happen the 22nd, so I can be back home by the evening of the 23rd, or on the 25th, which I could leave for as soon as I'm done cleaning up the building we rented for my grad party. Knowing my luck, however, the best chase day of the year will be the 24th....

After that, I am completely free and clear to chase whenever and wherever for several weeks, and I have a gut feeling the last week of May and first few weeks of June will be extremely active, particularly on the High Plains. Lord knows we're long overdue for bad weather around here, the last few summers have been almost dead quiet in terms of severe weather, especially in north central and northeast Colorado and into northwest Kansas and western Nebraska. It's about time we had a wild summer again...

 

[Marc Remillard]

I'm leaving Canada on May 14 with Rejean Boudreau and we plan to stay on the plains for 3 weeks. We'll be there for the 20-21-22ths possible paradise days... I got hope

 

[Paul Knightley]

For a number of days now, both the GFS and ECMWF ensembles (the stuff to look at for days 7 plus!) have been developing mean 500 hPa troughs over the western US. The GFS deterministic runs this morning have begun to trend towards this solution. I think from around 21-22nd May onwards, a rather active pattern should set-up although I do see the risk (beforehand) that a strong cold front could get right into the Gulf. Or I could be wishcasting, since we flight out to DFW on the 19th!

 

[Dan Cook]

Latest GFS runs shut down the ridge.

 

[Mark Farnik]

That 500 mb map is a thing of beauty! That is a very, very nice trough! Hopefully it pans out, as if the trough is in the posistion advertised on this 500 mb map, it would kick out onto the Central Plains the afternoon of Thursday the 22nd, which would be perfect timing for me! I could leave Wednesday night, chase Thursday and be back home in time for my high school Baccalaureate Friday evening!
If the weather gods are inclining their ear unto us, I beg of them on hands and knees, do NOT let this system slow down, as I will erupt into a fit of violent self flagellating frustration if a tornado outbreak occurs the 23rd or 24th...

 

[Andrew Stoller]

May 24th: Violent tornadic supercells in eastern CO. Bank on it!

 

[Scott Weberpal]

May 24th: Violent tornadic supercells in eastern CO. Bank on it!

Are we taking bets on this?

 

[Mark Farnik]

Very funny, Andrew. Now you've jinxed it!
But in all honesty, with my great luck and constant victimization by the strong arm of Murphy's law, this will be the case. I'm not placing any bets on it until the end of next week, I don't trust the models farther than I can throw them more than a few days out, especially this year.
Well, giving further thought to it, that actually might work out nicely IF it goes down. My grad party ends at 3 p.m., so if there's a nice, stout but breakable capping inversion that will hold intiation off until 4 or, preferably, 5 p.m., which will allow greater instability to occur in addition to giving me time to get to wherever I need to be, let the good chase times roll and the highly visible, uber spectacular tornadoes dance across the Colorado prairie!!!

 

[Cstok]

OK, we are still about a week out, but I like the changes I am seeing, and reading for middle of next week:

From this mornings AFD from DDC:
WILL FINALLY SEE DEVELOPMENT OF
LEE TROUGH AGAIN BY AROUND TUESDAY OF NEXT WEEK. JUST BEYOND THIS
FORECAST PERIOD...WE MAY BEGIN TO RE-ENTER A MORE CONVECTIVELY
FAVORABLE PATTERN ACROSS THE WESTERN PLAINS WITH A SYSTEM OF SOME
SHAPE OR FORM ENTERING THE INTERMOUNTAIN WEST REGION AND ROCKIES



Also like what I am seeing from the 5/13 00UTC ECMWF:

f

The most recent GFS shows this as a closed low coming in a little slower... some time later next week... but again I like the over all changes I am seeing... one concern however will be lack of moisture, depending how deep the prev. front pushes into the gulf.

 

[Andrew Stoller]

Whew, I don't know. Out past 140 hours on the GFS, a small closed low looks to break out of the ridge, but it's pretty weak and out to 240 hrs, the death ridge is still in place with that friggin pesky Hudson Bay low. No overall pattern breakdown.

 

[Cstok]

12z GFS run looks a little scarry:

What I think is intereting is the difference in the ECMWF:

 

[Mike Hollingshead]

Dang, last two runs of the ECMWF are screaming welcome to spring in about 9 days. Looks like it wants to make up for some lost time fast, lol. Today's 12z looks rather sweet.

 

[cdcollura]

Good day all,

Missing the action this week and past week due to move (sold my home).

On the GFS, I see the "sickening" upside-down horseshoe "omega" high sitting over the Rockies past May 14 to nearly May 20 (glad I'm not there)!

Past that time, troughing resumes and I should make my 10-15 day trip then, but need to be back to FL June2 for new job.

 

[Dan Cook]

Hmm..which model to believe. The GFS is ridge city while the Euro has a nice trough next week..

 

[Chad Cowan]

Euro has been showing that nice trough digging in mid- to late next week for a few runs now. Moisture and heat will be aplenty, and if we can get a favorable trajectory of that trough there could be 3-4 good chase days as the energy gets cut off and slowly creeps East. The operational GFS has been absorbing that energy into the NW flow, up and around the ridge. Although, the bowl of spaghetti in the GFS ensemble for the forecast period tells me that the operational output is a shot in the dark.

EDIT: New GFS run (14/12z) is more in line with Euro. It takes the trough further south and makes for a very favorable svr-wx setup. Still considerable uncertainty, but this run puts a 987mb low in W KS on Wednesday with 65 dews pushing as far north as NE. It's reassuring to see the GFS trying to be more like its long-range-savvy European counterpart.

EDIT 2: Uhhh, woah. Just looked at the 00z Euro fcst MSLP (http://meteocentre.com/models/ecmwf_amer_00/cep00_9panel.gif)... and um, it's pretty good. 977mb low in wrn NE on Wednesday. So we got that goin for us, which is nice.