Tier 04 · Local Risks · Winter Storm
Most winter storm harm comes from decisions made indoors: the wrong heat source, a frozen pipe you didn't catch, a freezer you opened too early. Here's what to have ready before temperatures drop.
Start with the 72-hour basicsRegional reality
Significant winter storms are a reliable hazard across the northern tier of the country, from the Pacific Northwest and Rockies east through the Great Plains, Midwest, and up the Atlantic seaboard. Lake-effect snow off the Great Lakes drops several feet in narrow corridors east of Erie, Ontario, and Michigan in hours. Northeasters can strand coastal cities for two to three days at a stretch.
The southern United States is a different category. A half-inch of freezing rain can paralyze a metro area that has almost no road treatment equipment. Texas, Arkansas, and the Carolinas see ice storms that cause more disruption per inch of precipitation than a two-foot snowfall in Minnesota.
The National Weather Service issues a Winter Storm Watch 24 to 48 hours out when conditions are possible. A Winter Storm Warning means conditions are expected. A Winter Weather Advisory covers lesser accumulations still likely to cause hazardous travel. The watch is your cue to act, not the warning.
Alert levels
Winter Storm Watch
Issued 24–48 hours before. Conditions are possible. This is your window to act.
Winter Storm Warning
Issued 12–24 hours before. Conditions are expected. Most preparation should already be done.
Winter Weather Advisory
Lesser accumulations. Travel will be difficult. Hazardous but not a full storm event.
Ice Storm Warning
A quarter-inch or more of ice accumulation expected. More dangerous per inch than snow.
Preparation
Your 72-hour and two-week prep handles water, food, and communication. Winter storms add three specific risks those tiers don't fully address: heat loss, pipe damage, and carbon monoxide from indoor combustion. The items below are winter-specific additions, not replacements.
01
Any combustion-based heat source produces carbon monoxide. Test your detector now. Replace any unit more than seven years old. Keep one within 10 feet of every sleeping area.
02
A propane heater labeled "indoor safe" (such as the Mr. Heater Buddy series) differs from a camping model. Know which you have. $80–$150 for a reliable unit. One 1-lb canister gives roughly 3 hours at the low setting.
03
Foam pipe insulation wraps exposed runs in unheated spaces, basements, and garages. Costs less than $30 for most homes. Install it before the first freeze, not during one.
04
A battery or hand-crank NOAA radio receives watches and warnings when your phone has no signal and the power is out. The Midland ER310 is a reliable choice at $50–$60.
05
If your primary heat source fails, sleeping bags are the most effective single-item warmth solution. One per household member, rated at or below the coldest outdoor temperature you could see.
06
Charged battery, antifreeze at the right concentration, half a tank of fuel minimum, and a basic car kit (ice scraper, traction mat, jumper cables, mylar blanket). Check these in October, not December.
Heat strategy
Trying to heat an entire house with a small supplemental source is a losing equation. Pick one room before you lose power. Pick it for size (small), location (interior, south-facing window if possible), and layout (door you can close).
A small bedroom with a closed door retains heat several times longer than a connected open-plan living area. Move bedding, medications, pets, and young children into that room before temperatures drop indoors, not after.
Lay a rolled towel along the base of the door to reduce drafts. South-facing windows gain passive solar heat during daylight and should be uncovered. North and east-facing windows lose heat, cover them with heavy curtains or spare blankets.
The CO rule is absolute
No generator, grill, camp stove, or vehicle engine inside the house or attached garage. Even with a window cracked. Carbon monoxide is odorless, colorless, and builds faster than most people expect. The CO detector must be working and audible from your heating room before you light anything.
Safe indoor heat sources
What to wear before you light anything
A three-layer system keeps a person comfortable at indoor temperatures as low as 50°F without supplemental heat:
The indoor risks
Pipes freeze when temperatures drop below 20°F and unheated spaces go unmonitored. The most vulnerable runs are against exterior walls, in unheated crawl spaces, and under sinks on outside-facing cabinets.
More people die from CO poisoning during and after winter storms than from exposure or frostbite. Most cases are preventable. The source is almost always a generator, grill, or vehicle engine used in an enclosed space.
Power outages and food safety follow a predictable timeline if you keep the appliance doors closed. The main variable is how full the freezer is when the outage starts.
During the storm
Most of what a winter storm requires is already decided before it arrives. These steps cover the decisions that come up once the storm is active.
On ice driving
If the roads are icy and the trip is not necessary, don't make it. That judgment is the most important item on this list.
Black ice forms when pavement is wet and temperatures drop to 32°F or below. It's most common between 28°F and 32°F. Bridges and overpasses freeze before road surfaces because cold air contacts them from below as well as above. Treat every bridge as icy even when the road before it looks clear.
If you must drive: tell someone your route and expected arrival time. Keep the tank at least half full. Travel during daylight. Carry a basic car kit with an ice scraper, traction mat, jumper cables, a mylar blanket, and a small shovel.
Stay home if there is any question about road safety
Most winter storm deaths happen in cars. A decision to stay put protects everyone in the household and reduces demand on emergency services during their highest-stress hours.
Verify the CO detector is working before using any heat source
Press the test button. Confirm it chirps. Then light the heater or start the fireplace. This step takes 10 seconds and belongs at the top of the list.
Move household members into the designated warm room
Don't wait until the house gets cold. Move bedding, medications, water supply, and pets into the heating room before temperatures fall inside. Reheating a cold person is harder than keeping a warm one warm.
Check pipes every few hours during severe cold
Run a cold tap briefly to confirm flow. If pressure is low or a faucet produces no water, the pipe may be starting to freeze. Shut the main water supply immediately if a pipe has already burst.
Do not open the freezer unless necessary
Eat perishables from the refrigerator first. Leave the freezer sealed. Every time it opens, cold air escapes and the safe-food window shortens.
Check on neighbors, especially those who live alone
A knock on the door during a storm costs two minutes. Elderly neighbors and those with medical equipment are most at risk during extended power outages.
Recovery
Cleared roads are not the same as safe roads. The recovery window carries its own risks: ice from melt-and-refreeze cycles, CO from cleanup equipment, and the structural damage that only becomes visible once snow starts to shift.
Wet snow weighs 20 pounds per cubic foot. A foot of heavy snow on a flat roof can exceed safe structural limits. Walk around the outside of the house and look for signs of stress: cracking sounds, doors and windows that have started sticking, visible bowing in the roofline.
An ice dam forms when heat escapes through the roof, melts snow, and the runoff refreezes at the cold eaves. Water backs up under shingles from there. The fix is attic insulation, not roof raking in most cases.
Keep the faucet open while applying heat so steam can escape. Use a hair dryer, heating pad, or warm towels. Start at the faucet end and work toward the frozen section. Never use an open flame.
If you can't find the frozen section, or if the pipe is behind a wall, call a plumber. A pipe that has already burst will be obvious when you restore water pressure: shut the main supply immediately and call for help.
A snowblower, generator, or pressure washer running in a garage produces enough CO to reach dangerous levels within minutes. The storm is over, but the ventilation rule is not.
Keep all gas-powered equipment operating outdoors, with exhaust directed away from doors and windows. This is where most post-storm CO incidents happen, not during the storm itself.
A plowed road can still have black ice. Overnight temperatures below 32°F refreeze meltwater on already-cleared surfaces. Morning commutes the day after a storm are often more dangerous than the storm itself.
Your state's 511 road conditions line gives real-time surface treatment information. Check it before assuming a road is clear.
Local resources
Current watches, warnings, and advisories by region. Wind chill charts, safe temperature thresholds, and shelter guidance.
weather.gov →
Federal preparedness checklists, state emergency management directory, and shelter location resources.
ready.gov →
Warming shelter locations, storm-specific guidance, and local chapter contacts. Search by ZIP to find your nearest chapter and open shelter.
redcross.org →
Real-time road surface treatment and closures by state. Available by phone (dial 511) or web. More current than traffic apps during storm events.
511.org →
National Weather Service locator for warming centers during extreme cold events. Updated by county emergency managers.
weather.gov →
Carbon monoxide statistics, safe placement guidance, and CO detector placement specifications from the Centers for Disease Control.
cdc.gov →
Starting out
Water, food, light, medicine, comms, and documents. This checklist is doable in a weekend and it covers most of what any hazard actually requires.
The 72-hour checklistHave the basics
Winter storms that knock out regional grids run longer than 72 hours. The two-week tier covers power, heat, sanitation, and medical buffers for extended disruptions.
First 2 weeks guideBrowse other hazards