UPDATE 3:30 PM, 3/16: Roanoke has reached 77 degrees today, the warmest day since Oct. 25. A band of showers near the I-64 corridor in Virginia and West Virginia will move southeast into parts of Southwest Virginia later this afternoon or early evening. With temperatures having warmed so much as the surface, some thunderstorms are possible, and there is even a limited risk of gusty winds or marginally severe hail. A taste of spring indeed on a day with so many outdoor events — but colder weather is ahead for most of the rest of March. END UPDATE
Saturday will have some showers, but probably not enough to wash out the St. Patrick’s Day festivities in Roanoke and other outdoor events. The biggest batch of rain will slide through mostly Roanoke and northward — some healthy rainfall totals in West Virginia, dwindling out to under a quarter-inch along the U.S. 460 corridor through the Roanoke and New River valley and southward — during the morning hours, likely wrapping up by mid to late morning. This rain will be associated with a warm front swinging ahead of a low-pressure system moving to our northwest. With southwesterly winds behind the warm front and some sunshine poking through the clouds, high temperatures in the mid 60s to near 70 are likely on Saturday afternoon, If that verifies, it would be the warmest afternoon we’ve had so far this March. Friday’s high of 65 in Roanoke equalled that of March 10. Blacksburg’s warmest so far was also on March 10, 64 degrees. A few showers may be possible at times in the afternoon, but again, a widespread, soaking rain is not expected.
Don’t get used to Saturday afternoon’s springlike warmth. It’s not getting sprung for good, just yet.
Saturday’s warming southwesterly winds will flip around to east to northeast behind a cold front sliding southward late Saturday or early Sunday. This will set up the familiar wedge pattern, with colder air becoming trapped against the mountains, through Sunday into Monday. Moisture overrunning the colder air will lead to periods of chilly rain, with temperatures holding in the upper 30s to mid 40s in most locations across Southwest Virginia. That’s just cold enough to raise the specter of possible frozen precipitation, and it does appear that some spots north of Interstate 64 and perhaps higher elevations above 3,500 feet to the south of there may see some snowflakes or sleet pellets at times, though a widespread or particularly troublesome winter weather episode is not anticipated (that could happen farther north from northern West Virginia into Pennsylvania). We’ll bounce back to near-normal temperatures — 50s highs, 30s lows, generally — at midweek before a stronger front reinforces the cold air by late week. Colder than normal temperatures are expected to dominate the central and eastern U.S. for most of the next two weeks. About next Friday or so, a wet storm system may cross the Southeast as cold air builds in deeply through much of the East. It’s possible this will put Southwest Virginia on the rain/snow bubble 2 days into astronomical spring. It’s too far out to speculate much about that system, but be aware that winter isn’t going quietly into any kind of good night this March.