The short answer
A Flood Watch means conditions are favorable and flooding is possible. Use the lead time to prepare. A Flood Warning means flooding is imminent or occurring. Follow the warning's locations and protective instructions now. A Flash Flood Warning calls for immediate attention and may require moving to higher ground without waiting to see rain or water.
Start here
- Open the complete current notice, not only a color or push-notification preview.
- Read the product type, covered place, issue and expiration times, impacts, and official instruction.
- If it is a warning, follow its instruction now. If it is a watch, use the lead time to prepare to act.
- Keep receiving official updates until the product expires or is replaced and authorities say the relevant area is safe.
Read the exact notice first
Flood products are not interchangeable. Check whether the notice is a watch, advisory, Flood Warning, Flash Flood Warning, coastal or lakeshore product, or storm-surge product. Read the named locations, time, hazard, expected impacts, protective instruction, and when the source last updated it.
If a summary differs from the source notice, use the source notice. An evacuation order or another current official instruction takes priority over a general article.
A watch means prepare
A Flood Watch means conditions are favorable for flooding. Flooding is possible, not certain or necessarily imminent. Monitor updates, identify higher ground, review local evacuation instructions, confirm destinations, and charge devices while travel remains safe.
Gather medicine, mobility or medical equipment, animal supplies, and essential records. Leave early if officials advise it or someone in the household needs more time.
A warning means act
A Flood Warning means flooding is imminent or occurring. Follow the locations and action in the warning. Move to higher ground or evacuate when directed, keep away from streams and drainage channels, and never walk, swim, or drive through floodwater.
A Flash Flood Warning describes dangerous rapid flooding that is imminent or occurring. If it covers your location and you are in a flood-prone or low area, move immediately to higher ground according to the warning and local instructions. Rain may be falling upstream rather than where you are.
Advisory, coastal, and storm-surge products
Expected or occurring flooding is below warning criteria but can still make roads, underpasses, trails, and low areas dangerous.
Significant flooding is expected, imminent, or occurring in the named coastal areas. Follow local higher-ground or evacuation instructions.
There is danger of life-threatening inundation from a tropical system. Follow evacuation zones and local instructions without waiting for visible water.
What changes this answer
General guidance becomes a personal decision through these details.
Watch, advisory, river warning, Flash Flood Warning, coastal product, and storm surge are not the same state.
Polygons, zones, named roads, streams, coasts, and forecast points determine where the instruction applies.
Higher ground, evacuation, avoiding a road, or monitoring can replace the general action.
Mobility, medicine, animals, communication, and departure time can make earlier action necessary.
Where this guidance stops
- This guide is advance education. During a warning, use the current official notice and local instructions.
- A cached notice can become stale, be extended, or be replaced. Keep its timestamp and expiration visible.
- The absence of a phone alarm does not prove that no warning exists.
Sources
Consequential guidance is checked against the linked source material.
- National Weather Service. Flood Warning vs. Watch. Official product definitions. Checked September 13, 2026.
- National Weather Service. Before a Flood. Preparation before flooding. Checked September 13, 2026.
- National Weather Service. During a Flood. Higher ground, evacuation, and floodwater guidance. Checked September 13, 2026.
General information, not advice tailored to you or a guarantee of safety. You are responsible for decisions about your safety. Follow current directions from local authorities. Read the safety disclaimer.