Severe Thunderstorms in the Central U.S.; Upper Level Low Over California

Scattered severe thunderstorms are possible today across central and eastern Minnesota, Iowa, and western Wisconsin. A few tornadoes, isolated very large hail, and damaging winds may occur. An upper level low will help trigger scattered thunderstorms over portions of central and southern California today along with a few inches of snow in the central Sierra Nevadas. Read More >

Getting The Word | Climatology | Winter Storms | Definitions

The National Weather Service uses the following definitions when describing winter weather:

An advance statement that severe winter weather conditions are possible within the next day or two.

An urgent statement that severe winter weather conditions have begun or will begin within about 12 hours.

Advisory

A statement that winter weather conditions are imminent or occurring. These conditions will cause significant inconvenience, and may become hazardous or life-threatening if safety tips are not followed.

Heavy Snow

Snowfall which accumulates to a depth of at least 4 inches in 12 hours or 6 inches in 24 hours.

Sleet

Pellets of ice composed of frozen or mostly frozen raindrops, or snowflakes which have melted and refrozen.

Freezing Rain/Freezing Drizzle

Rain or drizzle which falls as liquid then freezes when it strikes the ground or other surface.

Frost

The formation of thin ice crystals on the ground or other surfaces.

Wind Chill

A cooling effect caused when wind blows across exposed skin.