Tomorrow at this time we’ll be on a plane to Denver hoping to get our first glimpse at severe weather Saturday afternoon and evening. Here’s the preliminary plan for the chase:
Saturday – Denver to Salina/Hays, KS on I-70 (somewhat limited based on flight time)
Sunday – Oklahoma or northern Texas panhandle (this is marginal – depending on how the forecast evolves we may ditch this altogether)
Monday – Travel day and enjoying the huge ridge
Tuesday – Nebraska or South Dakota
Wednesday – High plains of South Dakota or Nebraska panhandle
The plan on Saturday is to drive from Denver to somewhere between Hays and Salina, KS to intercept the storms that form in the afternoon.
While instability doesn’t look terribly impressive with CAPE values around 2000 j/kg there is a fair amount of shear. Deep layer shear approaching 40 knots is supportive of supercells and there’s enough turning of the winds in the 0-1km layer for an isolated tornado.
The 06z GFS is shown above. The 06z NAM is more unstable but the issue will be how quickly Gulf moisture is able to stream back into the central plains tonight and tomorrow. The best area for storms looks to be on the Kansas/Nebraska line so we may cut north from I-70 if needed.
Sunday’s plan is more up in the air. There’s the potential for some storms over the Oklahoma and Texas Panhandle. These storms wouldn’t be tornadic but could be high based or even LP supercells given strong shear, some instability, and enough boundary layer moisture and weak upslope flow. Here’s a forecast sounding off the 06z NAM.
Depending on where we wind up on Saturday I’m not sure if this is worth it or not. We’ll have to see how the threat evolves – at least right now it looks marginal at best. One possible reason to go would be to try for a 72 oz free steak at the Big Texan Steak Ranch in Amarillo.
Monday will be a travel day up north into Nebraska or South Dakota. Northern plains and high plains action will begin on Tuesday as this powerful shortwave ejects east from the Rockies.
Both the GFS and Euro have been advertising this for days. While some of the area will be capped (i.e. southern Nebraska?) the cap should weaken sufficiently for big boomers in northern Nebraska and South Dakota. Where the best shear/instability sets up it’s unclear. It’s also unclear how strong the cap will be (at least initially some places in Nebraska will have 700mb temperatures near 15C!).
With any luck we’ll get a high plains South Dakota or Nebraska panhandle day on Wednesday before we return to Denver on Thursday.