May 31, 2012

Today we blew off the risk in southeastern Texas as we would have to race the rapidly progressing gust front spit out by the MCS that plowed trough Kansas and Oklahoma last night. With shear parameters and the setup it was not worth chasing a linear mess and follow the front all the way to the Gulf. May 30th's chase turned out for the better as we were able to get on a rapidly intensifying supercell just northwest of Guthrie, TX. It popped up behind the main line and we suspect it initiated by the convergence along the outflow boundary from a large supercell to its southeast and the dryline. The inflow was nuts and had us driving through blinding dust storms as we tried to race ahead of it. Still unsure if it produced a tornado due to all the dust obscuring out view but it dropped some massive hail near Guthrie that we were able to play with after.

June 1, 2012 Forecast

Tomorrow looks to be marginal right now but if CAPE values can get up into the 3000 j/kg range we may be in business. Aloft the flow is marginal but is still on the lower end of what is suitable for severe thunderstorm development. The one down side is that we will once again be dealing with a northwest flow, but I'm not complaining since it has been producing for us this season. What I'm interested in as the 500 mb wind maxima shown here for tomorrow afternoon which is rounding the base of the main jet axis into the northeast portion of the Texas Panhandle. As this feature round the Rockies there should be some mesoscale stretching which could lead to enhanced vorticity and weak lee cyclogensis. 

Low level flow, particularly at the 850 mb level is pretty weak until about 00Z in through the northeast Panhandle region but by 03Z and around sunset the  low level flow should strengthen sufficiently to enhance low level shear. It is for this reason that the large CAPE will be needed, to be able to tap into the minimal shear initially close to initiation along stationary boundary between weak lee cyclone in eastern New Mexico and outflow from ridge sitting in southwestern MO. The resulting stationary boundary will extend from Wichita Fall, TX up to Amarillo then into northeastern NM will be the trigger for initiation as seen below. The CAPE maxima looks to establish itself in the vicinity of this boundary thus peaking my confidence that there should be supercell modes, this is further reinforced by veered hodographs in the vicinity of the boundary. Later in the evening as upper impulse strengthens and MCS should develop. The NAM/WRF and 4 km WRF precip models both indicate a precip maxima in the northeast portion for the Texas Panhandle with the 4 km WRF precip model keeping isolated supercells by 00Z with moderately rotating updrafts, as shown in the final image. Thus target for tomorrow Pampa, TX.