samuel stone
EF3
At the surface, primary surface cyclone will be over northern Minnesota/southern Canada, with resultant cold front arcing back south then south west into the central high plains where secondary surface cyclone will deepen to 999 mb by 0z. Dryline (which has become better defined with latest NAM run) is progged to stretch across central Kansas the south southwestward through western Oklahoma into western Texas by 0z. Latest NAM run also backs the surface flow more than with prior runs wich brings in mid sixties dew points at least through much of eastern Kansas and all of Okahoma. Marginal ssw 850mb flow atop sse surface flow will yield Helicity of up to 200 m2/s2 east of the dryline in Kansas as well as Forecasted CAPE of up to 2000-2500 j/kg across most of Oklahoma and central/eastern Kansas, and hints at a bullseye of 3000 j/kg in south central Kansas. So that all sounds great but things get kind of dicey in the middle and upper levels of the atmosphere. First, Models forecast 2 separate H5 waves to progress across the area Monday. One will push across the across the forecast area around 12z and followed by subsidence
Through much of the day until the next Wave approaches the area by 0z. A couple of concerns with this, 1) will the first Wave spark convection early in the day and keep clouds and rain across the target area for too long? 2) Will subsidence in wake of the first wave linger across the area to long and prevent deep convection from initiating?
Typical of rescent events (excluding 5/5/06) is the lack of speed shear in the atmosphere, even with good directional shear this could cause a problem with storm structure, not to mention the northwesterly upper level flow presents its own set of problems.
Now back to the possible early morning convection, one upside I can find in it is that if it does clear in time it could put out some outflow boundaries to aid in storm rotation. Another upside to it is that it could reduce mixing enough to keep dewpoints from mixing out along the dryline, and that combined with the early clouds/crapvection keeping temps down a bit will keep LCLs from being too high. Keep in mind that if temps stay down a bit it may not hurt us too bad as far as convective initiation goes since cap will be rather week in Kansas, in fact lower temps combined with subsidence in wake of first Wave may aid in holding down convection until the next upper waves kicks in later in the afternoon evening.
Overall I think a complex situation that I think has the possibility to be very good or be very bad depending some of the processes that I have talked about above.
Thoughts?
Through much of the day until the next Wave approaches the area by 0z. A couple of concerns with this, 1) will the first Wave spark convection early in the day and keep clouds and rain across the target area for too long? 2) Will subsidence in wake of the first wave linger across the area to long and prevent deep convection from initiating?
Typical of rescent events (excluding 5/5/06) is the lack of speed shear in the atmosphere, even with good directional shear this could cause a problem with storm structure, not to mention the northwesterly upper level flow presents its own set of problems.
Now back to the possible early morning convection, one upside I can find in it is that if it does clear in time it could put out some outflow boundaries to aid in storm rotation. Another upside to it is that it could reduce mixing enough to keep dewpoints from mixing out along the dryline, and that combined with the early clouds/crapvection keeping temps down a bit will keep LCLs from being too high. Keep in mind that if temps stay down a bit it may not hurt us too bad as far as convective initiation goes since cap will be rather week in Kansas, in fact lower temps combined with subsidence in wake of first Wave may aid in holding down convection until the next upper waves kicks in later in the afternoon evening.
Overall I think a complex situation that I think has the possibility to be very good or be very bad depending some of the processes that I have talked about above.
Thoughts?
Good luck to all chasing today, I'm not expecting a tornado but I'll take one. Hopefully I'll get to see some good storm structure.
