Memorial day weekend and beyond.

[Ray Walker]

Guys I just got throught pouring over some weather models and the GFS and several other models have been catching my eye the past few days and I figured that since they are showing at least a little consistency I would start this thread.
The models are showing us going back into a stormy pattern starting this week and continuing on into the first week of June. Of particualar interest is the GFS which shows a deep powerful trough impacting the plains starting on Monday 5/28/07 and continuing into the first week of June. The models is showing a strong dryline int the eastern Texas panhandle/ Far western Oklahoma during the afternoon of 5/29/07 with a corridor of cape values exceding 4500j/kg across much of Oklahoma east of the dryline and southern Kansas south of a weak front. Directional shear doesent look great right now with 850mb winds out of the SW but that will likely change with a 995mb surface low in the SW Kansas or Oklahoma panhandle region.
All I know is the models continue to show a deep trough across the western states and good instability around the 5/28/07 period and continuing into at least june 1st or so. Chasers all I can say is GET READY!!!!!!!!!!!!

 

[Ilya Neyman]

I too have been keenly paying attention to the latest gfs runs that keep coming in off the printer, so to speak. The overall pattern it has been trending towards is one that I consider quite active and probably rather seasonal for this time of year. Note, it should not be unusual to see an active pattern for the Plains for late May and into early June but when you compare the trend from the last couple of seasons it does look different. Probably back to more of the "norm" and why it is that people chase in May and June.

I haven't looked at this morning's 12z run yet (for all I know at this point it could look totally different from what I am basing my comment on right now, but equally plausible is that it may be showing a very similar thing) but judging by the earlier runs and a gauge of the overall pattern tendency of hanging the trough back out west with renewed shortwaves dropping down and ejecting out this type of pattern spells periodic activity, some of which would probably be severe, right across the Plains providing multiple decent chase opportunities and perhaps even several sizeable events. This is certainly looking more impressive as an overall pattern than really what we had last season and I guess is back to the typical "opportunities" for this region and this time of year. What is harder to predict is for anyone reserving chasecations well in advance and this year we've seen a very consistent pattern with overall quiet periods punctuated by outbreaks, or active times lasting for several days to a week, before going quiet again for a week or two, sometimes longer, at a time. This is more in line with a semi-blocking but progressive pattern. Once again, the real challenge is for those folks trying to plan time off or chasecations well ahead of time, and wanting to be around during the active periods. The thing I see in the GFS for this and next week is almost more of a consistent, semi-progressive, active period with setups possible back-to-back or every couple-few days somewhere across the Plains, more notably the trends have been to bring the focus further south back into the central and even southern Plains for some of these potential situations as opposed to the emphasis being across the far northern Plains as progs were showing earlier.

It's also important to keep in mind that this time of year its the ripples, the subtle shortwaves, that zip across and in their interaction with an atmosphere sufficiently loaded with moisture and cape, can lead to big-time thunderstorms, despite the mid and upper level flows much different from those of earlier in the season. There have been numerous examples where high instability and moisture alligned with "marginal" or not very impressive shear to produce some big days over the years. If the Gulf is open, and there is at least some decent flow traversing the lower 48 states, severe wx would be highly probable somewhere and at some time.