Weather all part of a random cycle

With summer well underway but without the typical dry heat to show for it, Bill Laidlaw, consulting meteorologist and owner of Signal Weather Services, said while this is a cooler year compared to others, this is not a first nor will it be the last.
The most recent set of normals have not been compiled yet but using the 1971-2000 set, it showed April was 2.1 degrees below normal, May was 4.8 degrees below normal, June was 2.2 degrees below normal, and July has been 3.1 degrees below normal so far.
Laidlaw indicated the standard deviation, or normal spread, of the temperature is within 2.2 degrees on either side of the normal.
So, with May and July being outside of that range, these months can be considered very cold by normal standards.
The pattern of rainfall so far this summer has made for a more dreary season than we’re used to, but we actually have received less rain than normal.
At first, the Fort Frances area received 12.8 mm less than normal of rain in April, and five days as opposed to eight days of rain that month.
Then in May, the area experienced the flip side of that with 25.4 mm more than usual of and 15 days of rainfall instead of 12 (not to mention that freak snowstorm).
Lately, however, the amount of rain has decreased although the number of rainy days has been on the rise. In June, for instance, rain levels were just 2.2 mm below normal but there were three more days of rain.
And so far in July, Fort Frances has received less than half of its expected rainfall but with a staggering nine days of rainfall out of 17 (when the whole month usually only receives 12 days of rainfall in total).
So, the summer of 2008 is shaping up to be dreary, cold, and miserable—nothing anyone wishes to see.
Between the forest firefighters who base their income on hot, dry, and windy summer months, farmers who need a balance of dry and wet, or just the sunny-day beach lovers, no one seems to be getting what they want.
Laidlaw agreed this weather is not normal compared to 30 years of compiled data, but that it is part of a pattern Northwestern Ontario experiences on occasion.
He explained that when you plot each day’s average temperatures for all 30 days of all of the months of June in the data set, you actually will find the tendency of two peaks: one just above the average temperature and one just below.
The reason for that, said Laidlaw, is because in this specific geographic location, it is seldom we can be found in the mean condition.
This stems from the fact there’s an imbalance of temperatures, with too much hot air at the Equator and too much cold air at the North Pole. This causes a warm air mass to move north while the cold air pushes south.
These opposing masses push the jet stream into an ‘S’ shape all the way around the Earth.
Northwestern Ontario happens to find itself in the middle of the upper hemisphere and, therefore, in the middle of this ‘S.’
“The thing is that at our latitude, there is space for five-and-a-half waves. You can’t have half a wave! It doesn’t make sense,” exclaimed Laidlaw. “So what that tells you is that [the weather in this area] is inherently unstable.”
As well, because Canada touches oceans on both sides, there are currents that both heat the air and cool it. Canada’s width allows for either two pushes north and one drop south, or one push north and two drops south.
Again, he explained that because Fort Frances is situated centrally, it can be affected by either the push or the drop.
Since this happens all year-round, one easily would estimate that in the winter we would find ourselves in the drop south and in the summer we are usually hit with the warm dose of air surging north.
But as we see with this summer, that’s not always the case.
So, that’s why there is a two-peak distribution pattern in Northwestern Ontario—it just depends on if there is a cold push or a warm push.
“We’ve been in a cold push pretty well all this spring,” confirmed Laidlaw.
“I can count only 10 days since the first of April where our temperature has been more than one degree above normal.
“The rest of the time the temperatures have been below normal.
“So if anyone asks if it’s been a cold spring, yeah it has,” he laughed.
But before anyone gets too upset by the news, Laidlaw assures the recent temperatures are by no means record-breaking.
“It comes back to this whole pattern thing,” he explained. “We’ve done this before. In fact, historically, only one month that has never had frost in Fort Frances is July.
“We had frost in August—Aug. 11, 1954 it was minus-1.1 degrees [Celsius].”
“So yeah, it’s a cold year but as you can see, we’ve done this before and in the long, big scheme of things, we will do it again.
“We’ll have warm years, too, though,” he assured.
On the brighter side of things, there’s some indication the season won’t end this way. In fact, it looks a lot like warmer weather ahead.
Laidlaw said the reason we’ve been so cold this season is because we have been on the west side of a cold push. But recently, it seems the cold push has “shut off.”
Instead, it is moving down the west coast.
“So what that means is we are getting into a southerly push and we’re starting to get the warm air flowing north,” he noted.
“Now, it’s going to take a while for things to switch around,” Laidlaw conceded. “But the big thing that we are going to see with that is that the nature of our rainfall is going to change.
“We are going to get more dry, warm days followed by violent thunderstorm activity—our typical summertime pattern,” he said.
Laidlaw also indicated this heat should continue on into the fall. So it isn’t necessarily a short season, just a late one.
The big question many people tend to ask when confronted with evidence their local temperatures actually are decreasing is, “Isn’t this supposed to be the age of global warming?”
According to Laidlaw, the 1961-1990 normals suggest the overall average temperature for the year was 3.2 degrees while the 1971-2000 normals suggest the mean of 3.5 degrees.
This indicates an overall rise in temperature by 0.3 degrees. So it is a change—even if it is minute. But he said this is typically how these shifts show up.
He noted the widely-publicized “global warming” statistics are highly dramatized and everyone has to remember that it is at a global level. So our 0.3 degree upward shift is only a part of the worldwide scale.
As well, it’s essential that people are aware these also are model projections.
“It is very similar to people who are predicting the performance of mutual funds,” Laidlaw explained. “Now the guy who wants you to buy the ‘XYZ’ fund is going to show what it has been doing over the last ump-teen years.
“But if he really wants you to buy, he’s going to show you its best performance graph. But whenever you go back and read the fine print at the bottom, bottom, bottom, it will say ‘past performance is no guarantee of future results.’
“So with all of these projections, it is saying if everything stays the same—there is no change in anything that is going on—then that is probably what will happen.
“Basically, if ‘X’, ‘X’, ‘X’, ‘X,’ ‘X,’ ‘X’—if all of these things stay the exact same, then most likely this will happen,” Laidlaw laughed. “But it’s hard to sell something like that.
“The big thing to remember is that both the deniers and the Chicken Littles are puffing up their cases to sell you on something that is primarily to their benefit,” he reminded.
As for what the future holds, Laidlaw said we just don’t know for sure.
“It could turn out that it warms up overall much more than the most dire [global warming] predictions; it could be that we’ve already hit the peak and are starting into a cooling trend.
“The most probable outcome is that the mean temperature of the Earth will continue to rise if nothing else changes for a while yet,” he said.
“We all would like to have our science in nice, neat little boxes—this one doesn’t come that way,” Laidlaw stressed. “It’s messy, sloppy, and it’s got a lot of ‘well, if . . .’ going down.”