6/10/06 FCST: KS/MO/NE/CO/WY

[samuel stone]

At this point Saturday looks ok so I decided to start a thread

Stationary front should set up over Kansas and Missouri with a 997 surface low progged by the 12z NAM to set up over southwestern Kansas/northwestern oklahoma. given strong istability along the front Tstorms should inititate atleast from eastcentral kansas into missouri during the late afternoon with more conditional develpment (because of strong cap) possible further west into central or northwestern kansas. any storms south of the front along the dryline will be very high based so any thing good, similar to friday's set up will be along the east-weast stationary front where strongly backed surface to 850 milibar flow beneath strong 700 milibar wsw flow will yeild helicity on the order of 200-250 m2s2, that combined dew points that the NAM proggs to be in the 70's over eastern kansas (possibly slightly overdone?) and a drop off from temps of 95 degrees south of the front to 80-85 degrees along and north of the front should yeild favorable lcl's (finally).
Also the 12z Nam proggs CAPE along the boundary in kansas and missouri of 3000-4000 j/kg. So the low level enviroment looks solid but I still I have some concerns about the upper flow, although slightly stronger at 500 milibar than friday by 5 kts acoording to the 12z Nam (30kts) and also good veering in the upperlevels in combination with backing in the low levels is favorable for good directional shear, but I still think that things may have trouble remaining supercellular afrter initial development, bassically I would just feel better if 500 milibar flow were 10 kts stronger, although I do like how the flow is oreinted to the boundary (possibly may have a few sups ride along the boundary and tap locally increased turning along the bounadary?)


Also I have included Nebraska, Colorado and Wyoming in the thread for the threat of a upslope event with 12z Nam forecasting strong easterly winds advecting in 55-60 degree dewpoints beneath a good 500 milibar shortwave with a 40 kt jet max over spreading most of wyoming and western nebraska by 0z.

both possibe areaslook descent (upslope and stationary front)

Any thoughts?

 

[Tony Laubach]

Saturday's actually playing to the reasoning which will be my ultimate decision about tomorrow (Friday) in Iowa/Nebraska. Not cause I think the Saturday setup is better, but because I don't want to be 600 miles from home and a decent upslope event. Its something that's been brought up among Colorado chasers.

My target for Saturday based upon the ETA would reside along and just south of I-70 between Colby and Salina where CAPE, shear, and the boundry positions seem to be in the area. There's also the nose of all this which moves up into NE Colorado at 0z Sun which could prove to be interesting as 500mb flow is progged to be a bit stronger along the KS/CO border. The ETA is showing a vort max over the area with a hint of SW flow over SE winds. Moisture along the front range wouldn't need to be terribly high for storm development, but SFC temps in the 90s will definately keep LCLs very high, thus limiting tornado chances for this area.

Too far out to really make any judgement on Saturday; Front Range forecasting is tricky this far out and is typically better left til the morning off when you can see how the SFC is working out, especially if a Denver Cyclone comes into play, then you're talking a whole other ball game.

I do like the Colorado/Kansas upslope play for Saturday and will be watching it attentively.

 

[Mark Farnik]

I agree with Tony and Chris on the potential for Saturday and Sunday. I doubt that a stratus deck will be an issue this time around, even if one formed these 90 + degree temps would burn it up in an hour or two so that's one hurdle cleared. It now appears the best tornado chances are going to be in a northwest/southeast oriented corridor from Lusk, WY to Sterling, CO. The SPC mentioned possible tornadic activity if enough low level moisture could return to this area by late afternoon. I think it has some really good potential, so I'm going to beg and plead with my folks to let me go out tomorrow. My preliminary target: Kimball, NE. It's only 60 miles north of me, so I could be out the door at 3 p.m. and rolling into Kimball by 4 p.m., then adjusting northwards from there to intercept any supercells rolling southeast out of eastern WY/the Wildcat Hills.

 

[Mark Farnik]

It's 8:48 a.m. at the time and tone, the temp is a relatively cool 70 degrees and the dewpoints are in the mid 50's across all of eastern CO and into eastern WY/the NE Panhandle. Things are looking quite promising for this afternoon's convection. Winds are currently out of the east at 10 mph and this easterly component is expected to continue all day, reinforcing the dews and preventing significant mixing out from occurring. Also, as the cold front has already punched through eastern CO and continues moving southward, the high temperatures will be about 7-10 degrees cooler than they were yesterday, the result being lower LCL's more favorable for the formation of mesos and potential tornadoes. It appears the action will get started early as initiation is expected in eastern WY/northwest NE by 2 p.m. along the lee trough trailing southward from the surface low which will be moving into the MT/WY/SD border area this afternoon. As the afternoon progresses, the potential for tornadic activity will increase. From the SPC's 1300 UTC Outlook:
FORECAST HODOGRAPHS INDICATE SHEAR WILL BE FAVORABLE FOR SUPERCELLS AND POSSIBLE
TORNADOES WITH 50 KT EFFECTIVE SHEAR AND 0-1 K SRH IN EXCESS OF 100
M2/S2...ESPECIALLY IN FAR E-CENTRAL WY/WRN NEB PANHANDLE.
Given the good shear across the board, the mid 50's dewpoints and easterly wind component, I would say a mini outbreak of a half dozen or so tornadoes is possible in my previously mentioned corridor from Lusk, WY to Sterling, CO.
My preliminary target is Scottsbluff. I'm thinking if I leave my place by 2 p.m. I can get to Scottsbluff (100 miles north as the crow flies) by 3:30 p.m. and adjust my target from there. Good luck to all who go out today! Here's to some High Plains Magic! B)

 

[Cstok]

Currently sitting just north of Cheyenne on 25. Wind out of the south 10 -15 mph. Mid 70s, and dry. Watching alot of turkey towers go up over the front range. Will probably reposition farther north to Wheatland and get additional data from there. Fairly good cell begining to go up near Chugwater, base still fairly high, hoping as it moves SE it will tap deeper moisture.