Issued: 8pm on Sunday, May 11th 2025
Technical Forecast Discussion
Short-Term Forecast (Sunday 05/11/2025 through Tuesday 05/13/2025):
In the short term, the upper-level pattern across the Ohio Valley is expected to remain relatively zonal, though a weak mid-level trough will gradually progress eastward from the central U.S. This trough will support the development of a surface low that will track toward the Great Lakes. Ahead of this system, southerly flow in the low levels will transport Gulf moisture northward into the region, placing Athens within the warm sector. This setup will contribute to an increasingly unstable atmosphere through Sunday and Monday. A shortwave embedded within the broader flow will amplify slightly as it nears the Ohio Valley. This feature will provide increased synoptic lift, particularly on Sunday and into Monday. Jet stream dynamics may further enhance upper-level divergence, which, in combination with surface-based instability, will support scattered to widespread convection. Thunderstorms are possible during this period, especially as ascent increases ahead of the incoming cold front. While the overall severe weather threat appears limited, isolated strong storms cannot be ruled out given the available ingredients. By late Monday into early Tuesday, a cold front associated with the surface low will sweep eastward across the region. This frontal passage will bring an end to the convective threat and usher in a cooler and drier airmass. Behind the front, surface high pressure will begin to build in from the northwest, allowing for more stable conditions and a reduction in cloud cover through Tuesday. Winds will shift northwesterly post-frontal, reinforcing the drying trend and setting the stage for a quieter midweek period.
Long-Term Forecast (Wednesday 05/14/2025 through Saturday 05/17/2025):
During the long-term period, the upper-level flow becomes more amplified as a ridge begins to build over the central U.S. and a deeper trough takes hold across the western states. As the ridge axis shifts eastward midweek, it will bring increasing atmospheric stability to the Ohio Valley. This will suppress vertical motion and limit cloud formation, leading to generally dry and quiet weather for Athens from Wednesday through at least Friday. At the 500 mb level, the ridge is expected to settle over the Appalachian region by Friday, reinforcing subsidence and supporting calm conditions across southeast Ohio. This will allow surface high pressure to remain dominant, with clear skies and mild temperatures prevailing through much of the late week. The return of southwesterly flow on the backside of the surface high may begin to draw in low-level moisture by Friday, though the atmospheric column is likely to remain capped under the ridge, keeping precipitation chances minimal. As the ridge begins to translate eastward by Saturday, the Ohio Valley may become vulnerable to the influence of the next upstream shortwave trough. This could increase mid and upper-level cloud cover and introduce a slight chance of precipitation late in the day or overnight, depending on the timing of the approaching disturbance. However, confidence remains low at this time, and the majority of the long-term period is expected to remain dry and seasonably warm.
