Issued: 12am on Thursday, January 1st 1970
Technical Forecast Discussion
Short Term (Wednesday 8/14 through Saturday 8/17)
A weak and lingering cold front promoted some thunderstorm activity in Northwestern Ohio earlier today. Some of these cells will propagate southeasterly into the area before de-intensifying with sunset. Chances for any precipitation will decrease through the late evening, leaving prominent low-level moisture and another favorable setup of fog for overnight. In combination, soundings are showing very weak wind flow near the surface as well as a strong inversion within the PBL. Some lingering cloud cover may affect the amount of radiational cooling overnight, but some areas of fog development is likely between 3am-8am Thursday. A fairly WSW to SW’ly flow pattern takes shape as the Jet Stream remains NE’ly draped along the southern Great Lakes. Furthermore, shortwave troughing develops south of the region for Thursday as a stationary front develops along northern Ohio. This weak forcing and surface boundary will lift northeasterly as the day progresses and primarily affects northern and northeastern Ohio. Afternoon showers and thunderstorms may initiate further south of the front as dew points remain relatively high (upper 60s), CAPE values nearing 1000-1500 J/kg in addition to 25-30 knots of speed shearing. Any initiation that does occur late morning/afternoon on Thursday will pose minimal severity and will dissipate later that evening and overnight into Friday. High pressure of about 1016 mb fills in over the Central Appalachians as SW’ly flow dominates through Friday and into the weekend. Cloud cover will be limited and most likely afternoon cumulus as profiles within the lower-mid levels remain somewhat nearing. Despite the higher pressure in place, the lingering moisture, moderate WAA, low-moderate CAPE and weak upper-level forcing may promote some afternoon convection for Saturday and into early next period. Dew points will consistently remain in the mid-upper 60s alongside seasonal high temperatures through the period, which will create for humid and somewhat uncomfortable conditions.
Long Term (Sunday 8/18 through Tuesday 8/20)
Humid conditions likely to pursue as dewpoints slightly climb near 70 along temperatures potentially warming into the low 90s. Through Monday, possible convective initiation in the afternoon may introduce isolated showers and even a thunderstorm as weak and zonal flow persists. Looking further ahead, a more organized upper-level shortwave trough begins to dig across the northern Great Lakes late Monday. This disturbance will drag an associated cold front from the NW and into the region by early morning on Tuesday, which will introduce increased precipitation chances. In approaching, this surface boundary currently looks to slow and turn stationary throughout the day and into Wednesday out ahead of another warm front from the west.
