Canadian cold front makes its move across us Friday; some strong storms possible, then cool days for mid-August
The long-awaited Canadian cold front will push through western Virginia during the afternoon and evening Friday. As it bumps into some heat and humidity — 90 degrees possible in the Roanoke Valley south and east, mostly 80s elsewhere — some strong to severe storms and locally heavy rain will be possible. While we have already been under a weather pattern that has brought us mostly near-normal to below-normal temperatures for about a week already, this front will be the leading edge of a broader push of air that originated in the Arctic Circle, though modified substantially as it has made the trip through the warmer latitudes in central Canada. We will remain under the influence of this cooler air for several days, possibly into the middle part of next week, with most days seeing highs in the 70s to low 80s in SW Virginia and lows in the 50s to lower 60s, with some 40s possible in rural valleys and above 3,000 feet on any clear, calm mornings that occur. Generally, temperatures are expected to be about 5 degrees below normal (normal high/low for mid-August are 86/65 for Roanoke, 82/59 for Blacksburg). There is some chance a wave or two of low pressure will move along the front as it parks to our south and upper-level disturbances from the northwest interact with it. This could lead to more clouds and showers on a couple of days, keeping low temperatures a little higher than forecasts but possibly knocking several degrees off daytime highs. This remains a little murky for now, with the general expectation that the front will push far enough south to allow drier, cooler air to settle in most of the next 3-5 days.