Issued: 3pm on Sunday, September 6th 2020
Technical Forecast Discussion
Short Term (Sunday 9-6-2020 through Tuesday 9-8-2020)
A compact VORT axis will advect itself into the forecast area over the next 6-8 hours. With this positive differential VORT advection along with very weak WAA at 500 mb, isolated synoptically forced rain could be possible–especially in the northern portions of the state (where stronger WAA will exist). However, most of the region should just see clouds Sunday evening as WAA will not be terribly strong. After this VORT axis progresses out of the area, a brief period of NVA will allow brief clearing Sunday night into Monday morning. That is until another VORT axis, this one weaker, will cause an axis of confluence to generate a weak frontal boundary across the northern portion of the state by Monday morning. Downstream of this boundary, rain will be likely. With occlusion occuring with this disturbance as it passes south and eastward across the state, frontolysis will begin to occur. This will prevent precipitation from reaching into southern portions of the state. Portions of Ohio south of US-50 should stay dry Monday. With MLCAPE on the order of 1500-2000 j/kg, along with somewhat dry mid levels (entraining downdratfs, and promoting DCAPE near 800-900), an isolated damaging wind gust or two from cell clusters Monday afternoon will be possible, mainly west of I-71. Monitor the latest forecasts. After this disturbance makes its way through, NVA, along with negative differential thickness advection will promote ridge building across the forecast area. A summertime airmass will make its return to the area because of this. West of the forecast area, a cyclone will be generated because of a speed max located over Iowa and Wisconsin. This, along with pockets of positive vorticity advecting northward across the Midwest and Ohio will generate a warm front, which will assist in the SFC WAA into our area. Highs Tuesday should reach the upper 80s and lower 90s, with isolated afternoon convective cells possible.
Long Term (Wednesday 9-10-2020 through Saturday 9-13-2020)
Off to the west, a *very* strong VORT max, and associated shortwave will dig down toward the south. Strongly positive differential thickness advection will close this feature, and keep it mainly stationary over the western plains, and eastern Rockies regions. Meanwhile overhead, ridging will continue to provide the area with summer-like temps through Thursday. Isolated afternoon convective cells will be possible every day this airmass remains present. Eventually, this VORT axis will push itself eastward into our region (much later in the week, however). Pieces of energy will break off of the northern edge of the VORT max, and dig the jet a tad south on Friday. This will set a stationary boundary up across the state, near I-70, Thursday and Friday. North of this boundary, fall-like temperatures in the upper 60s and lower 70s will return. South of this boundary, summer-like temperatures will continue on Friday. A cold core high will push this boundary south, and cool southern portions of the state into the upper 70s by Saturday. With this cold core High, skies should remain mainly clear for Saturday.