Issued: 8pm on Wednesday, July 17th 2019
Technical Forecast Discussion
Short Term (Wednesday 7/17 through Saturday 7/20)
Post-tropical Barry still shows its presence with scattered showers and storms across much of the region as Wednesday comes to a close. Diminished rain chances as Wednesday night progresses with showers/storms wrapping up by midnight. Moisture in the lower levels is still hesitant to exit, leaving some cloud cover for the rest of the overnight hours and into the first part of Thursday. The associated shortwave feature will pass through and be pulled toward the east coast by early morning on Thursday and introduce higher pressure and drier weather for southeast Ohio. Upper level ridging builds not only across our area, but the southern and southeastern U.S. Broad high pressure also sets in for these regions, which will generate more strong southwesterly flow for Friday and into the weekend. In combination, the Jet Stream will turn zonal and be lifted well into southern Canada. This setup will establish a heatwave across many central and mid-west states posing dangerous heat and humidity values. Southeast Ohio will see high temperatures well into the mid-90s with dew point readings in the mid-70s through the rest of this forecast period. An excessive heat watch has been issued for Friday into Saturday as these heat indices may reach into the triple digits that could pose health risks to long outside exposure. Mostly sunny skies can be expected for Friday and Saturday, but with the presence of this abundant moisture, some passing clouds may exist during the daytime. This trend will change late Sunday and into early next week as the next profound upper-level trough dramatically digs north of the Great Lakes region with a cold front.
Long Term (Sunday 7/21 through Tuesday 7/23)
Temperatures stay hot for one more day as Sunday will see another high in the low 90s. This pattern will begin to crumble as an upper-level trough swings a northerly cold front through Sunday night and eventually passing early on Monday. Showers and storms may initiate earlier into Sunday out ahead of the front as convection seems favorable. Possible severity of some of these storms is unsure currently as shearing and CAPE values look minimal. More certainty will occur later in the week as more mesoscale model runs become readily available. Showers and storms look to continue into Monday as a secondary residual cold front passes through later in the evening. High pressure fills in Monday night and into Tuesday, which will introduce much lower dew points and dry weather for the end of this period and into mid-week. With the passing of this system, the Jet Stream very much shifts into a meridional pattern across the mid-west that will promote northerly flow for much of the region. This flow will advect broad CAA and will bring some relief to temperatures with highs near 80 and lows into the upper 50s and lower 60s.