Winter weather
Snowstorm vs blizzard vs whiteout
Not every heavy snow is a blizzard. "Blizzard" is a specific NWS classification with strict criteria. Here is what each winter storm term actually means.
The NWS definitions
Blizzard
Sustained winds 35+ mph AND visibility below 1/4 mile from falling/blowing snow, AND conditions lasting 3+ hours.
Ground Blizzard
Same wind and visibility criteria, but with no falling snow — all blowing snow.
Snow Squall
Brief intense burst of heavy snow with strong winds. Sudden onset. Sub-30-minute events.
Whiteout
Visibility below 1/4 mile in any snow event. Weather description, not a warning category.
Snowstorm
Generic term. No formal definition.
Winter Storm
NWS umbrella term for hazardous winter weather producing snow, ice, or a mix.
The regional storm types
Nor'easter
East Coast winter cyclone. Winds from northeast. 24-48 hrs. Heavy snow + coastal flooding.
Alberta Clipper
Fast-moving western US low. Light snow but often high winds.
Panhandle Hook
Rocky Mountain cyclone dropping through TX/OK. Common Plains blizzard producer.
Lake-effect snow
Cold air over warm Great Lakes. Localized bands with 3+ inch/hour rates. Downwind of lakes.
Colorado Low
Cyclone forming east of Rockies. Traverses eastward, brings blizzards to northern Plains.
Bomb cyclone
Any midlatitude cyclone dropping 24+ millibars in 24 hours. Extreme intensification.
Polar vortex disruption
Not a storm — an outbreak of Arctic air. Extreme cold, not necessarily snow.
Warning terminology
- Blizzard Warning — blizzard conditions imminent or occurring.
- Winter Storm Warning — significant winter weather occurring, includes heavy snow, ice, or extreme cold.
- Winter Storm Watch — winter storm possible in 24-48 hrs.
- Winter Weather Advisory — less severe but still hazardous.
- Ice Storm Warning — 1/4 inch or more freezing rain accretion.
- Wind Chill Warning — dangerous wind chills.
- Snow Squall Warning — new (2018+) short-fuse warning for burst events.
The snow-to-liquid ratio
Not all snow is equal. 10-12 inches of snow contains 1 inch of liquid water — the standard 10:1 ratio. But it varies:
- Dry, cold, fluffy snow: 20:1 or higher. Common in Rockies and northern Plains.
- Wet, heavy snow: 5:1. Common in Northeast at 30-32°F.
- Actual ratio depends on temperature at the DENDRITIC GROWTH ZONE (10-15,000 ft where crystals form).
- Snow ratio matters for structural loading, ability to remove, and travel.
Historic events
1888 Great Blizzard
March 11-14. NYC to Nova Scotia. 400+ dead.
1888 Schoolhouse Blizzard
January 12. Great Plains. 235 dead, many children walking home from school.
1978 Blizzard
January 25-27. Ohio Valley to New England. Snow drifts to 20 ft in NY.
1993 Storm of the Century
March 12-15. Alabama to Maine. 318 dead.
1996 Blizzard
January 6-8. Northeast. 30+ inches DC to New York.
2010 Snowmageddon
February 5-6. DC area buried.
2013 Great Storm Nemo
February 8-9. New England. 3-ft records.
2021 Winter Storm Uri
February 10-17. Texas grid collapse. 246 dead.
2022 Buffalo Christmas Blizzard
December 22-27. 40+ dead in Buffalo area.
Winter driving tips
- Keep tank above half full.
- Winter kit: blanket, hand warmers, water, snack bars, candles.
- Full charge on phone with backup battery.
- Kitty litter for traction if stuck.
- Snow chains where required.
- If stranded: stay in vehicle, run engine 10 min per hour with window cracked.
- Watch for carbon monoxide — clear exhaust pipe of snow.
Snowfall records worth knowing
- US 24-hour record: 75.8 inches at Silver Lake, Colorado (1921).
- US season record: 1,140 inches at Mt. Baker, Washington (1998-99).
- US city single-storm: 82.2 inches at Bethel, Maine (Dec 1969).
- Buffalo: legendary lake-effect, 100+ inches/year average.
- Fairbanks Alaska: coldest wind chill: -108°F recorded (1988).