Natty das - severe frontal storms

special weather statement

wintertime alert, least urgent

advisories

wintertime alert, for specific weather events (blowing snow, freezing drizzle). less severe

watches

wintertime alert. alert you when there is potential for significant storm/severe weather.

warnings

wintertime alert. urgent messages about severe weather. updated regularly for safety.

snowfall warning

a snowfall accumulation of 15 cm or more is expected in 12 hours or less

freezing rain warning

freezing rain is expected to last for 2 hours or more, or if slippery or hazardous walking or driving conditions due to freezing precipitation is expected.

frost warning

when the air temperature is expected to fall below or near freezing ( 0°C ) during growing season

winter storm warning

When severe and potentially dangerous winter weather conditions are expected, including:

A major snowfall (25 cm or more within a 24 hour period); and

A significant snowfall (snowfall warning criteria amounts) combined with other cold weather precipitation types such as: freezing rain, strong winds, blowing snow and/or extreme cold.

blizzard

caused by interaction between “upper level, low pressure trough” and “surface low pressure” visibility = less than 400 meters, windspeed = more than 40km/h, snow = more than 4 hours.

alberta clipper

moves south-east, moderate snow, strong wind strength, very fast. originates in alberta from dry, cold arctic winds

Maritimes Nor’easter

originates from warm atlantic waters, intensifying a low pressure system, picking up moisture from tropics. winds come from northeast where it moves up to the maritimes. heavy snow, strong wind, long duration

colorado low

moves to(quebec ontario), very heavy snow (big contributor for canada storms). strong wind and speed. low pressure system tapping into gulf mexico moisture.

sleet

mixture of rain/snow, with warming the snow melts, then with cooling it refreezes near but above ground level, forms mostly <1 mm diameter ice particles

freezing rain

Rain that freezes on impact to form a coating of clear ice (glaze) on the ground and on exposed objects.