Why Meteorologists Get Forecasts Wrong—and Other Fascinating Facts About the Weather

Forecasts aren’t guarantees

Your forecast might extend up to 14 days ahead, but don’t bet your vacation on it. “We can look at trends, but can’t forecast with any detail past seven or eight days ahead,” says Halifax meteorologist Jim Abraham. “The most accurate weather forecasts are for today and tomorrow.”

Forecasts may not be clear to everyone, either

Probability of precipitation is one of the most misunderstood parts of the forecast “A 40 per cent chance of rain means for any random spot within the forecast area,” says Abraham. If you’re commuting to work, you’re more likely to get wet than if you stay in one place.

There’s a big difference between a severe thunderstorm watch and a warning

“A watch means conditions are favourable for the development of a thunderstorm,” says Gerald Cheng, a meteorologist with Environment and Climate Change Canada. “A warning means it is imminent and you need to get indoors.”

The first lightning flash can happen before you see rain or hear thunder

“If you’re in an open area, try to be the lowest thing possible,” says Cheng. “Take shelter in your car, with the windows rolled up.”

Remember these other tips to stay safe from lightning.

Always have an emergency weather kit ready

A basic storm preparedness kit includes at least two litres of water per person per day (plan for at least three days), non-perishable food (replace it annually), a manual can opener, a hand-crank radio, and a flashlight with extra batteries.

Climate change is very real…

The world is warming. Long-term data show temperature increases of twice the global average in the Arctic, causing global climate chaos.

…and Canada has been greatly affected by it

Average temperatures have increased by a total of 1.7 C in Canada since 1948—twice as fast as the rest of the world. This has intensified storm activity, wildfires, floods and heat waves across the country.

Read the terrifying story of what it’s like to survive a fire tornado.

If you live near the Atlantic coast, always prepare for the worst

The most crucial information—where the hurricanes will go—depends on a delicate combination of winds, pressure systems and sea temperatures.

The polar vortex sounds like a scary new phenomenon, but it’s actually common

A few times each decade, jet streams—blasts of Arctic wind that would normally be corralled by air currents high in the atmosphere—break free, causing punishing winters farther south.

Find out what it was like on the coldest day in Canadian history.

The Old Farmer’s Almanac is rarely spot on

Because weather systems are chaotic, it’s impossible to predict weather trends beyond seven days ahead. Seasonal outlooks are unreliable.

Clouds don’t filter out UV rays

The daily UV index tells you the intensity of sunburn-producing ultraviolet radiation at any given location. At 3 and above, apply SPF 30 sunscreen every 90 minutes, even on cold and cloudy days.

Pay close attention to your body

The humidex and wind chill can help interpret how the day’s forecast will affect your comfort level, but they don’t take into account factors that make each person experience heat and cold differently, like body type, age and certain health conditions.

Not all weather apps are equal

Weather apps each rely on their own data models for forecasting, which is why they can predict different temperatures. Apps with certified meteorologists on staff will be most accurate.

Next, check out the fall forecast across Canada in 2020.