Issued: 7pm on Sunday, February 23rd 2020
Technical Forecast Discussion
Short Term (Sunday 2/23 through Wednesday 2/26)
An enclosed upper-level low will be one of two upper-level features that will begin to dig and make their approach onto the region throughout this Short Term… Relatively weak zonal flow aloft will exist across the upper Ohio River Valley overnight into Monday, while the Sub-tropical Jet becomes widely positioned throughout the southeastern U.S. Dry weather conditions will ensue, but as soundings begin to progressively moisten from the top-down by the predawn hours of Monday. This expected increase in cloud cover may play a role in maintaining Sunday night’s temperatures from falling out of the 30s. This prominent southerly flow will begin to increasingly advect in low-level moisture as dew point values seek the upper 30s by noon. By 18z Monday, a shortwave trough will propagate NE into portions of Oklahoma and Arkansas as a confined pocket of upper divergence becomes favorable within this location. Cooler air will quickly wrap this associated surface low and become strongly occluded with its increasing presence onto western Ohio. WAA within the lower levels will significantly increase through Monday afternoon as temperatures rise near 50⁰F. Drier air will still remain confined down near the surface and will likely postpone the bulk of the precipitation until later Monday evening and overnight, where a pocket of PVA downstream of this trough sweeps into southern Ohio. This weakening low will lift along the Ohio River Monday night into Tuesday morning and become situated across southern Ohio. Simultaneously, the next upper-level trough will strongly dig SE’ly through the Great Plains region and usher in much colder air within the wake of the previously exiting system. Combined flow and this strong forcing will generate a positive feedback and allow for re-intensification of the originally occluded surface low across the lower Great Lakes. A cold front will rapidly advance onto the region sometime Wednesday afternoon, which will advect in much cooler air by the evening hours. This colder westerly flow will promote below-freezing temperatures and a light snowfall overnight Wednesday with this leftover moisture. Relatively tight pressure gradients will develop throughout the Ohio and Great Lakes region as this surface low strengthens further northeast.
Long Term (Thursday 2/27 through Saturday 2/29)
Benign, but cooler weather conditions will develop through Long Term and into early next week… Cloud coverage will still remain increased through late week as the base of this upper trough passes further east of the region. However, an enclosed upper-level low within a long wave troughing pattern will encompass the greater Great Lakes region. Weather conditions will presumably remain dry, but fairly cold.
(*Next Technical Discussion will be posted on Wednesday 2/26*)