5/26/06 FCST: CO / NE / KS

TARGET: AKRON, CO TIME OF DEPARTURE FROM OKC: 7 AM - Marginal severe weather day is shaping up across portions of northeast Colorado, NW KS and W NE. Leeside cyclogenesis will allow moisture to return northward along retreating frontal boundary. Still concerned about weak winds aloft ahead of this system and whether or not surface moisture can make it back that far NW. Plan to stay in North Platte tonight then make the leap northward into the Dakotas tomorrow. TM
 
Interesting set up that I wasn't expecting yesterday as I am in Sioux Falls. I think there will be sufficient moisture and I liked the backed winds. I agree that the lack of upper level support is the main negative. Closest 500 MB winds of only 20 to 25 though there is a bit of a data hole. I'll head west and check more data before turning south, maybe in Murdo. prelim target Ogallah though I may have to shift westawrd.

Billl Hark
 
Quite nice to see that SPC has the Tri-State area (NE Colorado, SW Nebraska, NW Kansas) under 5% tornado risk for this afternoon. Last night actually was quite suprised as a strong bow echo developed out of nowhere near Hudson and raced clear to Kimball, NE in two hours, producing what was probably the most incredible lightning storm I have ever witnessed. Even my dad said he hadn't ever seen such an electrified storm in his lifetime, and he's 47 years old! That storm and others around it left good moisture and some OFB's behind, so I'm watching for convection to light up along those this afternoon. Hopefully the storms won't go as linear as they did on Monday and will remain of a more isolated nature. Today I am taking one final, and then after 4:00 p.m. I am free as a bird! So I think I will go back home and adjust my target from there.
Bill, you are absolutely right about the data hole. There is over 220 miles distance between the Boulder NWS office and North Platte NWS office, so there is quite a broad area where radiosonde data is not gathered from. I've found that the 500 mb winds are often times weak over the Front Range, but variably stronger farther east onto the Plains.
Tim, dewpoints are currently in the low to mid 50's here in eastern CO. As long as there isn't too much mixing out by mid afternoon, the moisture should be more than sufficient for supercell development and sustainment. And around here dewpoints often make a rebound after they mix out to some degree. Take last Monday for example. At 12:30 p.m. the dewpoints were in the low 50's. By 2:00 they had mixed out to the mid to upper 40's. Everyone was bummed... but wait! By 3:30 dewpoints had risen back into the low 50's, riding in on a generally southeasterly wind with an easterly component and convection began exploding all over the place! That is the nature of the High Plains. It should be a pretty good chase today. :D
 
I am concerned with the very warm 700mb temps progged by the RUC of 15 to 17C and producing a good cap.

However on the edge of the cap into part of sw NE could be interesting. If storms can slow to less than
10 mph then there should be adequate mid level SR flow for supercells with progged mid level winds of
20 to maybe 30kts. That said I also wonder if the cloud bases/LCL's/and temp-dewpoint depressions
a bit to high for tornados.

The other area of potential supercells are near the foothills of ne CO with the Denver Cyclone. Good
moisture pouring in from the southeast, but like others have said will it mix out?
 
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