Weather warning side companies like Weather Watch or Instant Weather. These side companies are not associated with the government in any way. Environment Canada defines a advisory as ""an alert to cover a wide array of deteriorating weather conditions,"" a watch as ""when conditions favour that severe weather forming"" and a warning as ""severe weather is actually occurring or is imminent."" . Additionally, Environment Canada breaks down weather alerts based upon the specific type of hazardous weather. These alerts are regionally issued throughout Canada and include, but are not limited to, winter storms, extreme temperature, ice, thunderstorms (including tornadoes), wind, tsunami, tropical
Weather front Weather front A weather front is a boundary separating two masses of air of different densities, and is the principal cause of meteorological phenomena outside the tropics. In surface weather analyses, fronts are depicted using various colored triangles and half-circles, depending on the type of front. The air masses separated by a front usually differ in temperature and humidity. Cold fronts may feature narrow bands of thunderstorms and severe weather, and may on occasion be preceded by squall lines or dry lines. Warm fronts are usually preceded by stratiform precipitation and fog. The weather usually clears quickly after a front's