Wednesday, February 21, 2007
Weather columnist Kevin Myatt: Winter temperatures go from extreme to extreme
Kevin Myatt is The Roanoke Times' weather columnist.
kevin.myatt
@roanoke.com
981-3341
Weather with Kevin Myatt
Recent columns
- We got graupel, but not on official record
- Moisture could get caught up in cold blast
- Forecast for Weather Journal: Partly print, with frequent Internet
- Column archive
Read the Weather Journal blog
- Sprinkles or flurries possible Tuesday, but maybe something bigger for the weekend?
- For now, it looks like a quiet, mostly mild week ahead for SW Virginia
- Coldest morning of winter so far likely across much of Southwest Virginia; Tuesday precipitation looking doubtful
- Weather Journal blog
#swvawx on Twitter
@KevinMyattWx
We are coming out of a stretch of winter that was displeasing for almost everybody.
If you like warmth, it was an absolutely miserable stretch of nearly five weeks, with persistent cold and some extreme cold. It felt all the worse considering how warm it had been in the weeks before the Arctic outbreak.
If you like snow, there wasn't much -- unless you live in one of those places that gets a lot when the northwest winds ride up the Appalachian slope. For most of us, those northwest winds mean flurries to maybe a dusting. The Feb. 6 Alberta clipper was really the only widespread snowfall during the entire cold snap, and Southside Virginia areas near Martinsville even missed out on that.
And to top it all off, many of you from Bent Mountain south into Floyd County, and in a few other scattered areas, went without heat and light for a few days last week because of an ice storm.
So it's probably a relief to almost everyone that we are moving from the Arctic-dominated pattern of the past several weeks to one featuring mild air coming out of the Pacific.
This pattern looks to last most of the next two weeks. Probably, it won't have the staying power of the November-January warm spell, and we'll have at least one more cold period in March.
It will be warm enough to bring an end to Roanoke's quest for a record-cold February. Through Monday, Roanoke's monthly temperature was averaging 29.4 degrees, or right between the 29.3 degrees of February 1979 and the 29.5 degrees of February 1978.
Normal temperatures in late February are lower 50s for highs and lower 30s for lows -- so even our seemingly mild Monday, with a high of 49 following a low of 20, was a below-normal temperature day.
With highs mostly in the 50s and lows mostly in the 30s from here to the end of the month, it will definitely be mild enough to pull the month's average temperature out of record territory, but almost certainly not warm enough on a consistent basis to keep February from ending as a colder-than-normal month.
Whether we get a record cold or warm month depends largely on whether or not weather pattern shifts occur just right to match the calendar.
We've certainly had a month of cold weather, and before that, more than a month of warm weather. But if the shifts between warm and cold occur in the middle of a calendar month rather than at the start of one, the month as a whole will be an average of the cold and warm periods and therefore end up more toward the middle.
Looking back on the 31-day period from Dec. 17 to Jan. 16, the average temperature was 47.3 degrees. If that had been a calendar month, it would have been the third-warmest winter month in Roanoke dating to 1948. That 31-day stretch could have been the second-warmest January or December on record, and was warmer than any February on record.
Similarly, looking at the 31-day period from Jan. 20 to Feb. 19, the average temperature during that spell was 31.5 degrees. That would have ranked as 14th-coldest out of nearly 180 winter months on record since 1948. It could have been the third-coldest February or the ninth-coldest January.
So we've had an extreme yo-yo pattern of late. Really, it dates back to at least late spring, as we went from a cool May, to a hot summer, to a cool early fall, to a warm late fall and early winter interrupted by one week of extreme cold in early December.
You often hear that normal is only an average of extremes. The last few months of weather seem to be proving the point.




