Watch vs Warning vs Advisory: What Each NWS Alert Means
A watch from the National Weather Service (NWS) means the risk of a hazard has gone up, but its timing, location or occurrence is still uncertain. A warning means the hazard is happening, about to happen or very likely, and it threatens life or property. An advisory covers less serious conditions that can still turn dangerous if people are not careful.
The same three words appear on tornado, flood, winter, heat, cold and wind alerts. Local NWS offices set most of the thresholds, so the numbers behind an advisory or a warning differ from place to place.
What does a weather watch mean?
A watch means conditions favor a hazard, not that it will happen. The NWS glossary says a watch is used when the risk of a hazardous weather or hydrologic event has increased significantly, but its occurrence, location or timing is still uncertain. The purpose is lead time, so that people who need to set plans in motion can do so.
NWS safety pages give watches the action label Be Prepared. The NWS describes a Flood Watch this way: it does not mean flooding will occur, but it is possible. For thunderstorms and tornadoes, the Storm Prediction Center FAQ puts it in one line: a watch means severe weather is possible during the next few hours.
What does a weather warning mean?
A warning means the threat is here or very close. The NWS glossary defines a warning as an alert issued when a hazardous weather or hydrologic event is occurring, is imminent or has a very high probability of occurring. The NWS uses warnings for conditions that pose a threat to life or property.
NWS safety pages label warnings Take Action! For severe storms, NOAA’s Storm Prediction Center (SPC) says a warning means severe weather has been observed or is expected within the hour. A Tornado Warning, for example, means a tornado has been sighted or indicated by weather radar.
What does a weather advisory mean?
An advisory sits one step below a warning. The NWS glossary says advisories highlight special weather conditions that are less serious than a warning. They are for events that may cause significant inconvenience and, if caution is not exercised, could lead to situations that threaten life or property.
The NWS flood safety pages give advisories the label Be Aware. Common examples are the Winter Weather Advisory, Heat Advisory, Cold Weather Advisory, Wind Advisory, Dense Fog Advisory and Flood Advisory. There is no Tornado Advisory or Severe Thunderstorm Advisory.
How do the levels compare across hazards, and who issues them?
| Hazard | Watch (be prepared) | Advisory (be aware) | Warning (take action) |
|---|---|---|---|
| Tornado | Tornado Watch | None | Tornado Warning |
| Severe thunderstorm | Severe Thunderstorm Watch | None | Severe Thunderstorm Warning |
| Flooding | Flood Watch | Flood Advisory | Flood Warning, Flash Flood Warning |
| Winter storm | Winter Storm Watch | Winter Weather Advisory | Winter Storm Warning, Blizzard Warning, Ice Storm Warning |
| Heat | Extreme Heat Watch | Heat Advisory | Extreme Heat Warning |
| Cold | Extreme Cold Watch | Cold Weather Advisory | Extreme Cold Warning |
| Wind | High Wind Watch | Wind Advisory | High Wind Warning |
| Hurricane | Hurricane Watch, Tropical Storm Watch | None (NHC advisories are information bulletins) | Hurricane Warning, Tropical Storm Warning |
Tropical alerts follow the same logic with fixed timing. The National Hurricane Center (NHC) defines a Hurricane Watch as an announcement that sustained winds of 74 mph (119 km/h) or higher are possible, issued 48 hours before tropical-storm-force winds are expected to begin. A Hurricane Warning means those winds are expected, and it is issued 36 hours ahead.
Most alerts for your county come from your local NWS forecast office. The main exception is severe storm watches: the SPC issues all Severe Thunderstorm Watches and Tornado Watches, while your local NWS office issues the warnings for your area. According to the SPC, a typical watch covers about 25,000 square miles (about 65,000 square km), roughly half the size of Iowa.
Local offices also set most criteria, and the differences are large:
- Heat: the NWS Baltimore/Washington office issues a Heat Advisory east of the Blue Ridge when the heat index is expected to reach 105 to 109°F, and an Extreme Heat Warning at 110°F or higher. The NWS Twin Cities office starts its Heat Advisory for the 7-county Minneapolis–St. Paul metro at a heat index of 95°F for at least 3 hours.
- Snow: Baltimore/Washington’s Winter Storm Warning starts at 5 inches (13 cm) of snow or sleet for most of its area. Twin Cities uses 6 inches (15 cm) or more.
- Cold: NWS Omaha issues an Extreme Cold Warning for wind chills or temperatures of -30°F or colder. Baltimore/Washington uses -10°F east of the Blue Ridge.
Is there anything above a warning?
Yes, for a few hazards. The NWS issues a Tornado Emergency or a Flash Flood Emergency in exceedingly rare situations, when there is a severe threat to human life and catastrophic damage is happening or about to happen. Both carry the Catastrophic damage threat tag inside the warning.
“Particularly Dangerous Situation” (PDS) wording marks rare high-end events. The SPC uses it in Tornado Watches when long-lived intense tornadoes are likely. Since on or about October 1, 2026, NWS offices can also add PDS wording to Blizzard Warnings and Ice Storm Warnings for storms of extreme and historic severity, according to NWS Service Change Notice 26-52.
Below the advisory level, local offices issue Special Weather Statements, which the NWS describes as headlines for less serious hazards.
Are NWS alert names changing?
Several names changed recently under the NWS Hazard Simplification project. On or about October 1, 2024, Wind Chill Watches, Warnings and Advisories became Extreme Cold Watches, Extreme Cold Warnings and Cold Weather Advisories. On or about March 4, 2025, Excessive Heat Watches and Warnings became Extreme Heat Watches and Warnings.
A larger change is planned. The NWS has said it will drop the Advisory and Special Weather Statement headlines and replace them with plain-language headlines that start with the hazard name in capital letters, such as SNOW, WIND or HEAT, followed by the impact. Watches and warnings will stay as they are. The NWS says it will announce the start date in a Service Change Notice at least six months in advance. Advisories were still in use in 2026: NWS Anchorage, Alaska, began issuing Heat Advisories on or about June 9, 2026.
Where can you see the alerts in effect for your area?
- Go to weather.gov and enter your ZIP code, or click your area on the national map. The NWS points the public to this method since it retired its separate alerts webpage, alerts.weather.gov, on or about December 2, 2025.
- Read the full alert text. Its What, Where, When and Impacts lines give the hazard, the counties, the time window and the expected effects.
- To see every active NWS alert in one list, open our live list of NWS alerts by state, or go straight to a state page such as active NWS alerts for Texas. These pages show official NWS data in one place; they are not alerts themselves.
- Check that your phone can receive Wireless Emergency Alerts for the most dangerous warnings, as covered in our guide to how official emergency alerts reach you.
Bottom line
A watch means be prepared: the hazard is possible. A warning means take action: the hazard is happening or close. An advisory means be aware: conditions are hazardous but less severe. Thresholds differ by local office, so read the alert from your NWS office and follow instructions from local emergency officials. For hazard-specific detail, see our guides to tornado watches and warnings, winter weather alerts and heat alerts.
FAQ
Is a watch or a warning more serious?
A warning is more serious. A warning means the hazard is occurring, imminent or very likely, while a watch means conditions favor it. The NWS labels warnings Take Action! and watches Be Prepared.
Does a watch mean the storm will hit my town?
No. A watch covers a broad area where the hazard is possible, and the NWS says its timing, location or occurrence is still uncertain. Keep checking for a warning in your county.
Why are advisory and warning thresholds different in each state?
Local NWS offices set most criteria to fit local conditions. NWS Baltimore/Washington issues a Heat Advisory at a heat index of 105°F east of the Blue Ridge, while NWS Twin Cities uses 95°F for its metro area. NWS Anchorage issues Heat Advisories when highs reach 70 to 80°F for two or more days, depending on the zone.
Do all warnings go to my phone?
No. The NWS sends Wireless Emergency Alerts only for a set list: tsunami, tornado, hurricane, typhoon, storm surge, extreme wind, dust storm and snow squall warnings, plus flash flood warnings tagged Considerable or Catastrophic and severe thunderstorm warnings tagged Destructive. Watches and advisories are not sent this way.