Another interesting statistical tidbit about March 2012: It was only the second month in any year since official records began at 1912 that Roanoke averaged 10 or more degrees above normal. March’s average of 57.4 was 10.1 degrees above normal. January 1950, at 47.5 degrees, was 10.9 degrees above normal. For the record, there have been 5 months averaging 10 or more degrees below normal: December 1917, January 1918 (yes, back-to-back months), March 1960, January 1977 and February 1979. The coldest month on record relative to normal: March 1960, with an average of 34 degrees, a whopping 13.3 degrees below normal. That might not be too surprising in a March that produced 30 inches of snow.
Since 1912, there has never been an April that has averaged cooler than the March that preceded it. I don’t think this April will, either, but next week may give it a fighting chance. Signals are growing that the bill is about to come due for the warm March with a several-days period of cooler than normal temperatures starting about the middle or latter part of next week. A cold front that passed through Wednesday evening will help bring an installment of the cooler weather in for the late week and weekend. Highs will struggle to make 60 Thursday and Friday, with some lingering showers especially south of Roanoke, and lows may be near or even a little below freezing in many locations across Southwest Virginia by Saturday and Sunday morning. Though Easter will start chilly for sunrise services, very dry air moving in behind the front will be warmed quickly by the sun, with highs again jumping into the 70s in many locations by Sunday afternoon. A strong cold front arriving around Tuesday or Wednesday of next week will punctuate a developing shift in the weather pattern that features strong high pressure and, therefore, above-normal temperatures over the Rockies with colder air pulled into the Eastern U.S. around the high’s clockwise rotation into a deep low-pressure trough, or southerly dip in the jet stream. With the Rockies high flanked by similar low-pressure troughs both east and west, this pattern may not break down very quickly. The result is likely to be a period of below-normal temperatures, and perhaps even some downright cold weather at times. (Normal temperatures for early/mid April are mid-upper 60s highs/low to mid 40s lows for Roanoke, and low 60s/mid-upper 30s for Blacksburg.) Certainly, some frosty mornings appear likely late next week, and a hard freeze is not out of the question on at least one morning. This does NOT appear to be a repeat of the extreme 2007 April freeze, in either intensity or duration, but considering the early growth many plants have shown in the June-like days of mid to late March, damage will be a concern if there is even a morning or two when temperatures are below freezing. There might even be a bit of snow next week, particularly as cold, northwest winds blowing upslope over the Appalachians squeeze out moisture behind the midweek front. As of now, this does not appear to be a long-term pattern change, and warmer weather may well return not long after the cool snap.
You didn’t really expect to have that March heat wave without some kind of April cold spell, did you?