Modifying Outflow
Morning satellite with observations
An outflow boundary is draped from near the Red River in southern Oklahoma, northwestward into the eastern portion of the Texas panhandle this morning. Ongoing convection in central to eastern Oklahoma will tend to decay with time, but may push the boundary a bit farther south into North Texas. Farther west, the outflow will likely stall and then retreat northward, at least somewhat, from the Texas panhandle into western Oklahoma.
Modification of the western portion of the outflow boundary and its surrounding area will be the focus for convective development this afternoon. Although trends and high resolution model data suggest that the atmosphere will become strongly unstable in central Oklahoma with considerable veering with height in the wind fields, a lack of more substantial forcing will limit, if not prevent, much afternoon convection during peak heating, let’s say in the vicinity of I-35. Farther west along the remnant outflow, particularly near where it intersects with low pressure in western Oklahoma, there is a greater likelihood of new convection later in the day. This boundary may align itself in a way to create a triple point with the low and a north-south oriented dryline. If that scenario occurs, the triple point vicinity would be the most obvious focal point for robust, isolated, or at least semi-isolated, convective development by mid-afternoon.
Winds near the boundary will remain backed out of the southeast, while winds veer to northwest around 500mb. These wind profiles, coincident with 30 to 40 knots of deep layer shear, would be favorable for at least initial supercellular development. Large hail will be the main threat, given large instability profiles and substantial veering of winds with height. Relatively modest winds in the low-levels will preclude a greater tornado threat.
Convection allowing models differ with evolution of convection this afternoon, but it’s possible than one or more mesoscale convective systems may develop from western North Texas into western/central Oklahoma by late afternoon. Whatever convection does develop will have a tendency to move from northwest to southeast across the southern Plains through early this evening. If a sustained supercell does develop, it will have a tendency to drop in a south-southeasterly to almost due south direction before merging with surrounding convection with time.
