A closed upper-level low will move eastward over Ohio on Friday night, before moving southeastward into West Virginia on Saturday morning.
Throughout Friday night and Saturday, easterly flow on the north side of this storm will continue to advect mid-level moisture into the deformation axis. With convection continuing aloft, there will be a modest probability of thunderstorms, although widespread rain showers are expected.
Throughout the region, total rainfall levels are expected to range between 1-1.3 inches through Saturday, with locally higher amounts also possible. River levels are expected to rise in the region, and certain rivers, mostly in Northeast Ohio, may see mild flooding as a result.
The National Weather Service has identified eastern Ohio as the focal point of ongoing moisture advection, with PW values of approximately 1.5 inches inches, which is close to the climatological high for early May. Aside from that, some higher resolution models are showing areas of qpf more than 2.5 inches, which indicates the possibility of localized flooding.
WPC has identified a Slight Risk of Excessive Rainfall in the southeastern region of the forecast area, which corresponds to around one-third of the whole forecast area.
Additionally, we will have a protracted period of east to northeast winds on Lake Erie in the 25-35 mph range throughout this time frame. As a result, the water level along the south side of the lake, west of Vermilion, will rise significantly. We will be keeping an eye out for any lakefront flooding as the weekend approaches.
Wet weather is forecast to diminish from the west to the east during the day on Saturday, with a low pressure system gradually filling and shifting to the southeast.
While Saturday will be a dismal day in general, the sky will try to clear for a while late Saturday night. Patchy fog may develop in areas where the skies have cleared. The rest of the day, a good push of clearing should take place by Sunday, with surface ridging and dry air moving into the area from high pressure over eastern Canada.
After seeing below-average highs in the upper 50's on Saturday, temperatures could rise into the mid-60's on Sunday as additional sun is expected.