UPDATE 11:20 PM, 7/14: Low 90s return for Roanoke Valley next few days, with afternoon showers/storms
UPDATE 11:20 PM, 7/14: Not much change for Sunday — a little hotter than today’s highs (87 for Roanoke, 82 for Blacksburg) with mid 80s to low 90s across the region. Daytime heating will boil moisture into afternoon showers and storms again, maybe not quite as much coverage or intensity as today, but a few heavier downpours are possible. This basic weather pattern appears likely to continue through at least midweek. END UPDATE
UPDATE 1:15 PM: A flash flood watch is in effect until midnight for the Roanoke Valley and Blue Ridge counties eastward. This flash flood watch does NOT mean everyone is going to see flooding downpours this afternoon. What it does mean is that locations that end up underneath slow-moving storms with torrential downpours may get 1-2 inches or even more very quickly, causing localized flash flooding. So it will continue to be feast or famine — try gluttony or famine — with rain today, as some sites get an overabudnance and others see little or nothing. Showers and storms will develop through the afternoon in the growing heat and humidity. Steering currents are weak, so storms will not move very much, and will dump large amounts of rain underneath the spots they form. Latest radar linked here. END UPDATE
It was 102 in Roanoke last Friday and Saturday. This Friday, the high was 78 — 24 degrees cooler than those highs, and only 1 degree warmer than last Sunday’s low temperature. Blacksburg has had four straight sub-80 highs, including a sub-70 high of 69 on Thursday, the first since June 6. But the cool, mostly cloudy pattern of the last few days is breaking down. Rain showers moving northward today was a signal that we are coming under the influence of Bermuda high pressure off the East Coast, with clockwise rotating returning moisture and ultimately heat back to Southwest Virgnia. Highs on Saturday will likely climb into the 80s most places, with mid to upper 80s from Roanoke south and east, and there will be scattered afternoon showers and storms in the increasing heat. The heat picks up Sunday through Wednesday as highs climb back into the low to mid 90s in the Roanoke Valley and points to the south and east, and well into the 80s in most of the New River Valley and westward. This will be a sticky moderate heat period, a few degrees above normal (87 for Roanoke, 82 for Blacksburg are normal highs this time of year) rather than extreme heat that will challenge records, and the heat will be interrupted by afternoon showers and storms here and there, from time to time. Down the road, late next week will see heat dome high pressure intensify over the Northern Plains and Upper Midwest, and it may try to build southeastward toward us by next weekend or early the following week. If that occurs, extreme heat would again become possible. The early bet is that the core of the heat stays west, and the high pressure may even be placed far enough west to sling a late-week cold front through to at least temporarily moderate the warmup. But it’s still a bit early to determine the details on how this will transpire.