Issued: 8am on Thursday, May 1st 2025
Technical Forecast Discussion
Short-Term Forecast (Thursday 05/01/2025 through Saturday 05/03/2025):
A well-defined upper-level trough currently digging into the central U.S. will continue to amplify as it progresses eastward toward the Ohio Valley. On Thursday, this trough will induce cyclogenesis at the surface with a deepening low-pressure system tracking across the Great Lakes. Ahead of the associated cold front, strong southerly flow will advect a warm, moist air mass into southeast Ohio. This will enhance instability, and with sufficient shear in place, scattered thunderstorms—some potentially severe—are expected to develop during the afternoon and evening hours. SPC has highlighted much of the region in a risk area for severe weather due to the potential for damaging winds, hail, and isolated tornadoes. By Friday, the cold front will have cleared the region, and the upper trough axis will pivot through. Behind the front, a cooler and drier air mass will settle in, driven by a broad area of high pressure building in from the Plains. The lingering cyclonic flow aloft, however, may support some stratocumulus development and a few isolated showers in the morning, especially where low-level moisture remains. Windy conditions may persist for part of the day as the pressure gradient remains tight. On Saturday, a secondary shortwave embedded in the northwesterly upper flow may dive across the region, enhancing cloud cover and bringing a chance for light rain showers. Surface high pressure will continue to expand eastward, limiting any significant moisture return, but weak lift associated with the shortwave may be enough to generate scattered activity. Temperatures through this period will remain below seasonal normals, especially Friday into Saturday due to persistent cloudiness and cooler air aloft.
Long-Term Forecast (Sunday 05/04/2025 through Wednesday 05/07/2025):
Heading into Sunday, ensemble guidance and deterministic models favor the development of a transient mid-level ridge across the eastern U.S., in response to an upstream trough digging into the western U.S. This ridge will bring a brief period of more settled weather across southeast Ohio, with moderating temperatures and reduced cloud cover. High pressure at the surface will be centered near the Mid-Atlantic region, promoting dry conditions and light winds. By Monday into Tuesday, the flow aloft becomes more zonal with weak embedded disturbances sliding through the ridge. A subtle shortwave trough is forecast to approach the Ohio Valley late Monday into Tuesday, bringing increased cloudiness and a renewed chance of showers. Confidence in timing and precipitation coverage remains somewhat limited due to spread in model solutions regarding the strength and track of this wave. By Wednesday, a broader trough may begin to approach from the central U.S., but the synoptic setup remains uncertain. Depending on the amplitude of the upstream ridge and trough axis, another round of showers may be possible midweek, but for now, precipitation chances remain low and dependent on further model consistency. Temperatures will gradually moderate through the period, trending closer to climatological averages by midweek.
