6/26/08 FCST: SD/NE/MT/WY/ND/IA

[John Hudson]

Attm, I'm thinking that it would be premature to count out SC ND from the list of possibilities, either. Latest 2100Z RUC is showing an insane area of CAPE over SC ND and NC SD, with values 5500 j/kg and more.

I know surface winds currently suck, but they are nicely backed over some of these areas, and morning convection in ND is just beginning to dissipate. If there's a little something left over for an OFB when heating maximizes, we could have a nice recipe for a good sized supercell or two.

Going to think it over, but I might be headed out there within the next hour or so. It is close enough for me to consider.


John

 

[Patrick Marsh]

Also I'm somewhat confused on how it will MCS so fast if we have good directional shear with SE winds and LLJ and W/SW 500mb winds?

Adequate shear is actually a necessity for a long-lived, organized MCS. The big reason for quick transition to MCS today will be the lack of a decent CAP to suppress widespread convection when the strong forcing moves through. It doesn't matter if you have all the shear in the world, if you have very high CAPE, weak CINH, and strong forcing...everthing goes up at once and storms immediately struggle by competing for moisture / dealing with cloud seeding, etc. With the decent shear, you may see embedded supercell structures within a MCS, but it will most likely be HP.

 

[Chris Allington]

Widespread elevated convection continues in may areas of the target area, Hopefully we can get enough airmass recovery for this afternoon, I think maybe it will be a good thing as it may hold storms off till a bit later or make things more isolated. Currently quite a few Severe thunderstorm warnings in E NE and W IA. I would try to play the SW corridor of the mod risk later this afternoon.

 

[Mike Hollingshead]

I'm targeting the Valentine to Merriman area still. I'd like to keep sw SD within reach, so am leaving now. The I80 crapvection isn't making me want to hang around too far east too long. RUC is building some extreme instability out there by afternoon. That next disturbance should be helping back the low levels again out there after noon. Hope things wait at least a little while to fire, as the upper support gradually gets better into NE the later you get. Good luck to anyone chasing today.

BTW there's a lovely one lane construction zone west of Merriman. Sat there for quite awhile last time. And I had great cell data till I was about 25 miles east of Merriman. Didn't get it back at all till I reached Gordon.

 

[Michael O'Keeffe]

The latest 12z WRF places the best area in a corridor from Norfolk to O'Neill. It is showing little convection on the precip model which is good to see considering we may see a more isolated supercelluar show! Based on the 0z the WRF was the outlyer with the precip now it is in line with the GFS and RUC. This is making me more optimistic, so we plan on leaving within the hour and head to Norfolk, NE initially. I also was impressed with the WRF overall showing crazy helicity values and nice moisture and instability.

EDIT: Check out the warm front on the latest WRF. Holy crap! Talk about a defined boundary, if a storm moves along that the tornado potential will rise significantly.

EDIT: Talked it over and called the chase off. Just not enough shear to us.

 

[Dustin Wilcox]

I'm not excited about today, if anything I think Mike has the right idea, if I were free to roam that far today (I'm not) I would be targeting Mission SD. I think further East the bouandary and juice is going to be to far south away from the best Upper level support, this early elevated stuff may tend to keep the boundary further South. There may be a robust storm or two fire in NE NE, though I'm not huge on the prosepects, SO many times I have been fooled by the "June/July Juice" and the subsequent outragous parameter values that it causes, seems I have been burnt a few times in that O'Neil area only for Cherry Co to be the show, never the less, I will likely end up that way, though if I were all out chasing today I would already be West of O'Neil and fudging WNW waiting for that SE screamer.

Seems RUC is picking up on the effects of this Elevated convection well, its tough to ignore that out that far West...


Just bring the 4 wheel drive...

 

[Andrew Stoller]

I'd head west for sure. Mike H has it right for Valentine, and maybe even further west from there as more isolated/discrete convection rolls off the Black Hills and the higher terrain further south. RUC does pop a cell the moves right over Valentine.

The upper trough has slowed way down or the models were way off. You have to go way west to find even 30 knot 500mb winds per the RUC. Surface low by 00z is around Cheyenne, so winds will be backed into the Sandhills and the Black Hills where a tounge of 65 to 70 degree dewpoints and resultant extreme CAPE get pumped in.

Anywhere east of Oniel and upper level support becomes practically non-existent and surface to 850 winds become veered at 00z.