March came in with a classic winter storm. April will come in with a classic spring storm.
---------
Though March will finish about 3 degrees below normal in temperature, the 7-10 inches of snow that covered the ground on March 1 (most of it actually fell on Feb. 28) seems far off after the first 70-degree temperatures of the spring on Wednesday.
Instead, we'll have a textbook spring storm that will bring heavy rain and some thunderstorms to the area Friday evening -- and then maybe a few flakes of snow to the highest mountaintop areas late Friday night and early Saturday.
The jet stream aloft these days is neither dipping deep south over us as it did earlier in the month to bring lots of cold air, nor is it arcing steeply north of us as it did in early January to allow warm air northward. It's pretty much blowing west to east over our heads, with a slight dip southward in the middle of the nation.
This dip is enough to allow upper level low pressure areas to dig in to our west, spinning up surface lows that track across the southern states and then up the Eastern Seaboard. These lows draw in warm, moist air from the Gulf of Mexico and pull down just enough cold air from Canada for a potent mix.
Over the Gulf Coast states into the Carolinas, it's a powerful enough collision for severe thunderstorms. We're not quite warm enough here for a lot of that.
Here, southeast winds ahead of the approaching low are likely to pull a wad of moisture out of the Gulf of Mexico and the Atlantic. This may spell heavy rain Friday night, similar to that early in the week. With the ground remaining moist from that episode, there are some flooding concerns.
As the low blows by Friday night, it will deepen over us. When it gets east of us, it's counter-clockwise circulation will pull gusty winds from the north. In the lower elevations like the Roanoke Valley, it will just make things a bit blustery on Saturday. Higher elevations along the Virginia-West Virginia border will probably see some snow. That's not really an unusual thing above about 3,000 feet, even two or three weeks deep in April.
The overall pattern is showing nothing really unusual, with gradually warming temperatures, interrupted by lows and cold fronts bearing rain and a brief cooldown every few days.
A winter of untimely extremes may very well be handing the baton to an amazingly average April.
