Issued: 8am on Thursday, August 21st 2025
Technical Forecast Discussion
Short-Term Forecast (Thursday 08/21/2025 through Saturday 08/23/2025):
Over most the short-term, a major upper-level ridge will remain over the continental United States with surface low-pressure near the region. This low pressure is expected to keep Thursday fairly cloudy, but with minimal chances for rain. Most of the moisture present during the entire short-term forecast will be near the surface at 850 and 925 mb, leading to most clouds that form to be low hanging. From 700 to 200 mb, an incredibly dry airmass will dominate with only some areas occasionally having a significant quantity of moisture. Weak instability from warmer air at 925 and 850 mb with relatively cooler air above it at 700 and 500 mb could be present through the next couple of days. While Thursday and Friday are unlikely to have any unsettled weather due to the dry air aloft and general sinking air from surface high-pressure, that could change once Saturday arrives. A trough will move over the region with a surface mid-latitude cyclone alongside it. This is expected to bring some moisture in the mid-to-upper levels of the atmosphere as well as some more instability as slightly cooler air aloft pushes in from the west while the near-surface stays warm. While the greater chances for showers will occur on Saturday, the minimal instability will not be enough for storms to confidently develop. For most of the short-term, relative vorticity and vertical velocity values are negligible, though by Saturday afternoon and evening slightly stronger values are expected to develop. Most of these stronger values will remain near the surface, so deep convection and precipitation development is unlikely at this moment in time.
Long-Term Forecast (Sunday 08/24/2025 through Wednesday 08/27/2025):
A noticeable cooldown is expected for the remainder of this forecast. Not only will cooler temperatures be expected at the surface with northwesterly winds bringing this air from Canada, but much of the atmosphere above will take in much cooler air than we’ve been used to this entire summer. While minor instability could help lead to possible thunderstorms on Sunday, it’s not expected any more than any showers are for Saturday. Vertical velocity values are strong Sunday, indicating fairly strong convective motion near the surface, and this would align with a surface frontal boundary moving over southeastern Ohio. Relative vorticity values aren’t anything to write home about, so it’s likely that any cells to develop may not last long in the region. This upper-level trough will remain over the region for the rest of this forecast, allowing colder air from Canada to fill into Ohio. This major cool-down will be supported by an enormous swath of high-pressure at the surface, allowing much of the warm daytime air to substantially cool our temperatures down; these low temperatures may even reach the 50s next week. By Sunday evening and for the remainder of the long-term, significantly drier air will fill into the region once more, drying out much of the atmosphere with stable conditions to follow.
