UPDATE 10:45 AM, 3/15: Scattered storms may take a bit off early March heat today into weekend; record high looking less likely for Roanoke today
UPDATE 10:45 a.m., 3/15: A slow moving area of heavy rain and storms in southern West Virginia (latest NWS-Blacksburg radar linked here) is ejecting high cloudiness eastward over Southwest Virginia, and that may be enough to shave a few degrees off high temperatures today. Some showers/storms may occur in parts of Southwest Virginia, especially west of Interstate 77, and perhaps eastward into the New River Valley, though the showers/storms will be outrunning their best source of lift and deepest moisture. Flash flood watches and some warnings are out for several counties in West Virginia, Ohio and Kentucky. END UPDATE
Roanoke reached the 80-degree mark, hitting 81, for the first time in 2012 on Wednesday. Quite likely, it will occur again on Thursday, when the March 15 daily record high of 82 set in 1944 will have maybe a coin’s-flip chance of being tied or eclipsed. Blacksburg, which came 2 degrees short of a record with its high of 75 on Wednesday, probably will not come that close to challenging its March 15 record high, also 82, set in 1973 (UPDATED; previously listed year 1915 was incorrect). There is no sign of real change in this weather pattern in the foreseeable future — maybe some hints it could shift a bit 2 weeks or so out, but that is way too out to be taken very seriously yet. The pattern, with dominant high pressure over the Eastern U.S. more akin to June than March, is allowing enough moisture and warmth to build that scattered showers and thunderstorms are likely to develop during several upcoming afternoons, possibly even a few on Thursday. Weak upper-air disturbances moving through will aid in triggering showers and storms, but it appears that any more organized storm systems will be blocked from entering the region and mainly stay to the west and north. (The Hydrometeroological Prediction Center’s 3-day rainfall map from Wednesday night shows health rain totals in Kentucky, but not getting east even as far as I-77 — maybe the far southwest tip of Virginia will see some of this.) While wind flow aloft is weak and more like summer, and therefore not conducive to large-scale development of rotating updrafts that can trigger supercell thunderstorms and tornadoes, the unseasonable warmth by itself may provide enough juice for a few strong storms to develop now and then, mostly with isolated gusty downburst winds and perhaps some hail. Most people in our region will not see these storms, though, and most storms that do develop will not be that strong. The main effect of the increase in showers, storms and clouds will be to nudge high temperatures back a few degrees after Thursday. 80 is possible any day the sun can beat down consistently, but a few of those days will likely be only in the 70s — “only” in the 70s being a very odd thing to say in mid March.