Issued: 8pm on Sunday, September 15th 2019
Technical Forecast Discussion
Short Term (Sunday 9/15 through Wednesday 9/17)
Presently, a high-pressure system ~1021mb lingers precisely southeast of Ohio as it resides through Sunday night. Partial clearing and calm winds may influence fog formation in the river valley locations, but may be governed and limited to the modestly dry (surface-lower) levels. Despite this, surface winds begin to veer in presence of a poorly organized mid-level disturbance that will impose on the region for Monday. In association, any upper forcing and strong flow aloft will be missing as a troughing pattern is located further east over the Atlantic coast. Progressing through Monday morning, this surface divergence will eventually dip further southeast as this mid-level disturbance drags a weak cold front NW’ly into the area. Modestly dry lower levels in addition to the weak gradients will greatly hinder and confine any precipitation ahead and along the front. Any shower or thunderstorm development will remain isolated along this boundary as its passage is expected around 18z-20z. In response, high pressure ~1022mb fills in over the Great Lakes as drier and northerly flow dominates the remainder of the day. Considerably drier and consistent weather will endure throughout Tuesday and the rest of this term as upper ridging amplifies across the western and central U.S. This vastly meridional flow will slowly propagate eastward extending its ridge axis over the region by early midweek. This developing ridge will keep the temperatures consistent and fairly warm with highs near the mid-80s.
Long Term (Thursday 9/18 through Saturday 9/20)
As of Thursday, this well-pronounced ridging will propagate further ENE and lift over the region. Higher pressure ~1024mb will persist over southern West Virginia and pump a warm S-SW’ly flow into the weekend. Drier and warmer weather will pursue through the weekend with unseasonable temperatures climbing into the mid and potentially upper 80s… Furthering the outlook, a slightly more organized upper shortwave is projected to dig across the central Plains and break down this ridging pattern. Strong and predominate southwesterly flow will enhance low-level moisture advection from the Gulf and strengthen a LLJ. ‘Currently’ the confidence for the timing of this disturbance is low, but is projected to influence SE Ohio sometime Sunday night as a cold front will extend from the WNW.