Issued: 8pm on Sunday, May 4th 2025
Technical Forecast Discussion
Short-Term Forecast (Sunday 05/04/2025 through Tuesday 05/06/2025):
The short-term period will remain influenced by a quasi-stationary frontal boundary draped across the Ohio Valley, supported by a broad, weakly amplified upper-level trough over the eastern CONUS. This boundary has served as the focus for repeated rounds of convection over the past several days, leading to saturated soils and standing water across the region. In response, an Areal Flood Warning remains in effect through Monday morning due to continued runoff and elevated stream and river levels. For Sunday night, lingering convection is expected to diminish as instability wanes and upper-level forcing weakens. However, given continued low-level moisture and the proximity of the front, scattered showers may persist into the overnight hours. A subtle shortwave embedded in the southern stream may pass through on Monday, promoting renewed scattered convective development in the afternoon, especially with any breaks in cloud cover. CAPE values will remain modest, and shear will be limited, so severe weather is not anticipated, but localized heavy rainfall cannot be ruled out. By Tuesday, the upper-level trough begins to lift northeast as a weak ridge builds in from the west. This will lead to decreasing precipitation chances and gradual stabilization of the column. Surface high pressure over the central Plains will begin to edge eastward, reducing low-level moisture and promoting clearer skies by Tuesday afternoon. Temperatures will remain near seasonal normals throughout the period, though some diurnal variability is expected depending on cloud cover and rainfall coverage.
Long-Term Forecast (Wednesday 05/07/2025 through Saturday 05/10/2025):
The long-term period will feature a more zonal to slightly ridged upper-level flow pattern across the eastern U.S., allowing for a brief window of quiet weather midweek. On Wednesday and Thursday, surface high pressure centered near the Mid-Atlantic region will dominate the region’s weather, bringing dry conditions, light winds, and seasonably warm temperatures. Skies should remain mostly clear as subsidence suppresses vertical development. By late Thursday into Friday, attention turns to a developing upper-level trough digging into the upper Midwest. This system will push a cold front southeastward toward the Ohio Valley by Friday. Return flow on the back side of the surface high will begin to reintroduce low-level moisture to the region, with increasing cloud cover and a rising chance of showers and thunderstorms by Friday afternoon. Current guidance shows moderate agreement in timing, though the strength and position of the frontal boundary could still shift. Saturday may feature post-frontal conditions, depending on the frontal progression. If the front clears the region Friday night, Saturday will be characterized by cooler and drier air with lingering clouds. However, if the front stalls or slows, continued unsettled conditions are possible with scattered precipitation. Ensemble guidance shows increasing spread by the weekend, so confidence decreases beyond Friday. Nevertheless, the general trend suggests a midweek break from active weather followed by a return to more unsettled conditions to close out the forecast period.
