After several days of summer-like heat and isolated strong thunderstorms, a much cooler and wetter weather pattern is expected to settle across Delmarva heading into the holiday weekend.
We are tracking a stalled cold front expected to remain just south of the region Thursday through much of Memorial Day weekend. This boundary will act as a focus for multiple rounds of showers as waves of low pressure and upper level disturbances move along it.
The unsettled pattern will begin as early as Thursday with scattered showers developing across the area, but the potential for steadier and more widespread rainfall appears to increase Friday into Saturday. Forecast guidance continues to show a developing area of low pressure tracking west of the region while strong high pressure to the northeast wedges cooler air southward into the Mid Atlantic. This setup may create a classic cool air damming pattern, leading to chilly northeast winds, cloudy skies, and periods of rain.
Rainfall could become heavy at times, especially on Saturday. Atmospheric moisture levels are forecast to rise significantly, with precipitable water values climbing between 1.50 and 1.90 inches, which is near the climatological maximum for late May. Because of this, there is at least a marginal concern for excessive rainfall and localized flooding if heavier bands of rain develop along the stalled frontal boundary.
Temperatures will also take a dramatic turn compared to the recent heat. Highs Thursday through Saturday may struggle well below normal in many areas due to persistent northeast flow, thick cloud cover, and repeated rounds of rain. Some gradual warming is expected by Sunday and Memorial Day as the stalled boundary weakens and shifts, although additional showers remain possible through the holiday itself.
While the timing is not ideal for outdoor plans and holiday travel, the upcoming rainfall will provide some beneficial moisture for the region as long term drought conditions continue across parts of the Mid Atlantic and Delmarva Peninsula.
Residents planning outdoor activities for the holiday weekend should stay updated on the latest forecasts as confidence continues to increase in a prolonged stretch of cooler and unsettled weather.
