UPDATE 11:45 PM, 1/10: It got a little warmer than expected Thursday with some sunshine — high of 59 in Roanoke, 55 in Blacksburg — but the wedge has fully set in as of Thursday evening, with low dew points and easterly winds. The somewhat cooler, drier air will mean any showers that fall into it, triggering evaporational cooling, will help keep temperatures down on Friday, in addition to the light easterly winds and clouds. Highs are unlikely to get beyond the low 50s in the Roanoke and New River valleys, unless there is substantially more sunshine than projected. Rainfall amounts will be light, less than a quarter-inch in most places. Springlike warmth is still expected for Saturday and Sunday. END UPDATE
It’s saying something when a “cold” air wedge situation in January means holding us below 60 the next couple of days. The weather map at left, which is actually for Friday morning, shows high pressure centered off the Northeast coast. That high will push some cooler air southwestward through much of Virginia the next couple of days. Cooler in this case means we don’t get runaway warmth that could take us into the 70s … that arrives on Saturday. The wedge of cooler air, once it sets in, could mean temperatures could hover around 50, especially from Roanoke north and east, on Thursday and/or Friday — normal highs for this time of year is 46. It looks unlikely we get much higher than the low to mid 50s the next couple of days. Either day could be one of those odd days when some parts of the New River Valley actually reach warmer temperatures than the Roanoke Valley does, depending on how many peeks of sunshine there are on the outskirts of the wedge. The other thing to note is the that the low-pressure center tracks north-northeast into the western Great Lakes, keeping the firehose of Gulf Moisture well to our west. Some light showers will be possible as some moisture overruns the cooler air the next couple of days, but don’t expect widespread, substantial rain — that may come the the early to middle part of next week.
The surge of warm air from the southwest overtakes us entirely this weekend to create one of the most outdoor-friendly weekends imaginable in January — though distasteful to those desperately seeking snow. It is within the realm of possibility that the following weekend could entirely flip this scenario.