A slow-moving storm center will move eastward tonight through Tuesday night over the next several days, bringing occasional showers and possible rumbles of thunder. Expect overnight lows this evening to range from the upper 50s in the higher elevations to the mid and upper 60s closer to the Bay. Also, expect patchy fog, mist, and drizzle patches in places. During the following few afternoons, it will be cloudy and cooler than average for late September. On-and-off rain showers, sometimes moderately heavy, will accompany the slow-moving storm center moving in from the west. The National Weather Service (NWS) has issued a Flood Watch for the Shenandoah and Rappahannock River Valleys from now until Monday morning. This is because the heaviest rain is expected south of I-66, with some instability and training potential closest to the storm's track. Multi-day rain amounts through early Wednesday are likely in the 2-4 inch range, with higher totals on the east slopes of the Blue Ridge Mountains. Given the saturated soils, swollen streams, and rivers from Helene's rains, flooding seems likely to occur sometime during the first half of this week. Given the slow motion of the upper low, uncertainty in the timing of the heaviest precip remains relatively high. By Wednesday, the first of two cold fronts will move in and help end the stretch of cloudy and rainy days. After the front passes, temperatures look seasonable, while the humidity will drop off to more tolerable levels for the rest of the week. Another cold front looks to cross our region late Friday night into early Saturday, but that front will come through the area dry, so expect just an increase in clouds with no rain. 7-Day Forecast: Tonight: Cloudy skies with scattered showers, mist, drizzle and patchy fog. Overnight temperatures are forecast to range between the upper 50s to the mid-60s. Monday: Cloudy skies with spotty showers, mist, patchy fog, and drizzle. Highs will be in the upper 60s to lower 70s, and lows will be in the 60s. Winds: ENE 10 mph. Tuesday: Cloudy skies with spotty showers, mist, patchy fog, and drizzle. Highs will be in the upper 60s to lower 70s, and lows will be in the 50s and 60s. Winds: NE 8-12 mph. Wednesday: Early clouds with a stray shower are possible, followed by partly cloudy skies in the afternoon. Highs will be in the mid-70s, and lows will range from the low 50s to around 60 degrees. Thursday: Mostly sunny. Highs are in the mid to upper 70s, and overnight lows are in the 50s to lower 60s. Friday: It will be mostly sunny early, with increased clouds throughout the afternoon and evening. Highs will be in the upper 70s, with overnight lows in the upper 50s to lower 60s. Saturday: Variably cloudy skies will become mostly clear. Highs will be in the 70s, with overnight lows in the mid-40s to the lower 50s. Sunday: Mostly sunny skies. Highs around 70 degrees.