OK, I do believe I’ve had about enough of this miserable spring weather. I mean, come on, getting an advective frost of -5C on May 14 is just a little too much! I can understand having a radiational frost, you know, when the sky clears up at night and the winds drop off and it gets really cold. At least with a radiational frost you know it will probably be nice and sunny the next morning and things will warm up quickly. The advective frost, on the other hand, is just plain nasty. The sky is cloudy, the winds are blowing strongly, and the ground is wet, so according to basic meteorology it should stay nice and warm at night, but it doesn’t.
An advective frost is when sub-zero air simply moves into a region and no amount of wind, clouds or moisture will help. It is also a very difficult frost to protect things from. Luckily for most of us, the weather has been so bad this spring that we either haven’t done much seeding yet or if we have, the plants haven’t yet emerged.
COOLER THAN 2004?
I think what’s making this poor spring weather particularly difficult to accept is the fact that, for most regions, May looks like it will be the sixth month in a row with below-average temperatures. In fact, if we don’t see a significant warm-up between now and the end of May, this May looks as if it will end up being colder than May 2004. Yep, I said it: 2004, the year when we barely had a summer. Now, I’m not saying that we are going to end up having a repeat of 2004. In fact, there are a few things going in our favour that make me think that we just might have a nice summer this year.
First of all, the weather pattern giving us this cool weather is not the same one that brought us the bad weather in 2004. In 2004 we had a pool of cold air sitting over Hudson Bay which continually pumped down cool, damp air. This year we have a very active long-wave pattern which is generating storm system after storm system. Each time a system approaches we see a brief warm-up, and then we either get hit by the system, which brings precipitation and cool weather, or the system just misses us, but we still end up with clouds and cooler weather. Then finally, the system pulls away, only to open the door for the cold air to slide southward, giving us several days of below-average temperatures – then the whole cycle repeats itself.
DUE FOR CHANGE
So this is one difference between our current weather pattern and that of 2004. The second main difference is the timing of our current long-term cool spell. Our current spell of below-average temperatures actually started way back in December and it has been cooler than average ever since. Looking back over the years, it is not very often that you find more than six months in a row with below-average temperatures. So from a climatological point of view, we are due for change in the weather pattern, from that of a colder-than-average pattern to that of a warmer-than-average pattern.
Maybe I am just being too much of an optimist, but let’s take a look at what our other long-range forecasters predict for the upcoming summer and see if they agree with my prediction that we will be switching to above-average temperatures very soon.
Over at Environment Canada they must be thinking the same way I am. Their current long-range forecasts call for a hot, dry summer across nearly all of Canada, never mind just Manitoba. Over at the Old Farmer’s Almanac they are not quite as optimistic. Their long-range forecast calls for near-to slightly below-average temperatures all summer long, with a wet start in June and then a dry end to summer in August.
Over at the Canadian Farmers’ Almanac, they seem to be calling for a perfect summer with near-average temperatures and precipitation. Finally, as I pointed out earlier, this cold spell just can last so much longer, so I am going to say we will see above-average temperatures this summer, along with near-average amounts of rainfall. I just hope that in three or four months I’m not eating my words and talking about the year without a summer!