Back in 2004 we had the year without a “proper” summer. Last winter it was probably the closest we could come to a year without a winter. Maybe this year it’s going to be the year without a spring. The longer we remain in what can only be described as a “deep freeze,” the better the chance that we’ll simply bypass spring and go right into summer. After all, by the time the end of April rolls around, the sun’s intensity is equivalent to that of mid-August.
So far for the month of April, we are running almost 10 C below the long-term average for the month. Since April usually starts off cold and warms up significantly toward the end of the month, it is not that unusual to see mean monthly temperatures significantly below the monthly average halfway through the month. What’s unusual is that the forecast does not show any significant warming for at least another week, which might just make April 2013 the coldest April on record.
Using Winnipeg’s long period of temperature records going all the way back to 1872, I searched for the coldest Aprils ever recorded. When you listen to Environment Canada, it typically only goes back to 1938 for Winnipeg records, since this was the year that the weather station was moved from St. John’s College to its current location at the Winnipeg airport. Personally, I like to look back at both data sets just to see what was happening way back when.
Here are the average monthly maximum, minimum, and mean temperature records in degrees Celsius.
Maximum: 2.1 (1950)
Minimum: -6.3 (1996) or -9.5 (1874)
Mean: -1.6 (1996) or -2.8 (1893)
So far this year Winnipeg has recorded the following mean monthly temperatures:
With two weeks still to go in the month I plugged these values into a spreadsheet, looked at what the weather models predict between now and the end of the month, and came up with the following prediction:
Comparing these to the record values, we can see a pretty good chance for us to see one of the coldest Aprils, if not the coldest April, in over 141 years! The one good thing we can credit the cold weather with this year is that the arctic high pressure responsible for all the cold has been so strong it has kept the major storm systems to our south. Hopefully, when the cold air finally pulls out it will do so quickly and the major storm track will jump past us and take up a new position well to our north.
After looking at all of this data I thought I would have some fun and take a look at what kind of weather followed these previous record-cold Aprils. 1950 probably had the worst weather out of all of these years. May was cold and wet with several shots of snow. June through to August 1950 was cooler than average with near- to below-average amounts of rain. 1996 had an April that was very similar to this year’s. May 1996 started off cool and wet but ended up on a fairly warm note. This warm weather continued into June, July and August. Along with the warmer-than-average temperatures, precipitation came in right around average each month. Going way back for the next two record years, April 1874 was followed by a warm and dry May and June and an average July and August. In 1893 May was cool with average amounts of precipitation, but June was warmer than average, with July and August coming in right around average in both temperature and precipitation.
So, if we had to base the upcoming summer on past experience we have about a 75 per cent chance of seeing near- to above-average temperatures with near-average amounts of precipitation. Oh, if only it were that easy!