Drifting Back to Oklahoma
HRRR forecast for 21z (Pivotal Weather)
Today’s severe weather setup drifts back toward Oklahoma. The surface setup features an area of low pressure over the Oklahoma/Texas panhandles, which will be moving slowly eastward through the day. South of the low is a dryline, which will mix east across the Texas panhandle. A trough extends generally northeastward from the surface low into southwestern to central Kansas. As of late morning, outflow from ongoing convection extends from far southwestern Kansas into northwestern Oklahoma.
The surface map combined with outflow and ongoing convection is a bit complex, but the expected outcome for thunderstorms later this afternoon is fairly clear.
The morning outflow boundary will probably sag just a bit more south before stalling and likely retreating some this afternoon. The boundary serves as a bit of a moisture axis, as 15z observations indicated somewhat drier air over north-central Oklahoma (low to mid-60s dew-points) compared to upper 60s/near 70 dew-points farther southwest. Even so, the gradient is not substantial and with several hours of daytime heating ahead, it’s fairly likely that the atmosphere will recover and become moderately to strongly unstable near the boundary by mid to late afternoon. Ongoing convection will ultimately limit destabilization farther north across Kansas, but that area is not the focus for severe thunderstorms today.
The target area extends from the eastern portion of the Texas panhandle into northwestern Oklahoma and southwestern/south-central Kansas.
The southern portion of the target area is interesting, as while there should be more mixing to result in somewhat lower dew-points (eastern panhandle region), convection should be more sparse, suggesting discrete storm modes would favor supercell development.
The northern portion of the target, along the surface trough, may see some moisture pooling on the southern fringe of early day convection. While the better low-level moisture may be more favorable here, cooler air aloft suggests a weak cap will result in considerable convection in the afternoon. This means that storms, potentially supercellular at first, will probably grow upscale quickly as they move toward the I-135/35 corridor in central Kansas.
Between the two areas is where the best overlap of ingredients is expected. This should be somewhere in the area between the eastern portion of the Oklahoma panhandle, northwestern Oklahoma and far southern Kansas. Basically, somewhere in the vicinity of Woodward, OK. Not only will this area be on the nose of low pressure and near an effective triple point (either the dryline/low/trough intersection or low/trough/outflow boundary intersection), but there should be less mixing of the environment, suggesting maximized CAPE profiles, unlike areas farther south. Convective mode will be the biggest question mark, but if storms remain relatively isolated here, they would appear to pose the greatest severe weather risk.
There are still several hours to go and it will be a waiting game in Liberal, KS, for the time-being. Once mesoscale details are resolved this afternoon with the outflow boundary, ongoing convection and surface observations, then the chase will begin. The general focus will be somewhere near Woodward, OK, but there is flexibility with road networks and time to either adjust south or north, if necessary.
