Every year, Environment Canada's Storm Prediction Centres produce about 14 000 severe weather warnings, 500 000 public weather forecasts, 200 000 marine forecasts, and 400 000 aviation forecasts. Each kind of forecast provides detailed information for a different purpose.
© Environment Canada
Photo: Pat McCarthy
Environment Canada issues severe weather bulletins to alert Canadians when hazardous weather is approaching. Three different types of bulletins are issued to let you know that something important is happening in the weather. A severe weather watch means you should do just that . . . watch the sky . . . and listen for updated messages because conditions are just right for something serious to develop. A severe weather warning is the next stage--it means something serious has developed and you should take action if you're in that area. Watches and warnings always tell you what the hazard is, where and when it's expected to occur, how long it will last, and how severe it's likely to be.
To see if any severe weather bulletins are in effect for your area today, check our online bulletin board. The third type, a special weather statement, can be issued when unusual or inconvenient weather is expected but is unlikely to reach the danger level. Learn more about severe weather in our weather office tour.
Public forecasts are issued for up to 5 days to help people plan their activities. These bulletins contain information on weather elements of wide-spread general interest: the amount of sun or cloud, high and low temperatures, likelihood of precipitation, and winds (when they're strong enough). Storm Prediction Centres issue public forecasts 3 times every day--in the early morning, just before noon, and again in the late afternoon. They'll also update the forecast between times, if conditions change significantly.
Marine forecasts are a little different. The information they contain is of special interest to people who'll be out on the water--wind speed and direction (even light winds), wave heights, and general weather conditions. This type of forecast is issued for waters along both the Pacific and Atlantic coasts, for the Great Lakes system, and in summer, for many larger inland lakes as well. You can see today's marine forecasts.
Aviation forecasts are completely different--they aren't even written in plain language! A special international code is used so that pilots from any country can read and understand the forecast. These forecasts include information that's important for aircraft operations, such as visibility and cloud height. Here's a sample of one below, issued for Pearson Airport in Toronto.
TAF CYYZ 111430Z 111512 36008KT P6SM FEW040 BKN090 OVC140 FM1600Z 33008KT P6SM BKN030 TEMPO 1604 4SM -SHRA BR BKN020 PROB30 1702 2SM -TSRA BR BKN015CB FM0400Z 04008KT P6SM BKN025 TEMPO 0412 BKN020 RMK NXT FCST BY 18Z=
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