Flash floods occur suddenly and usually within hours of heavy rainfall. Flash floods become raging torrents of water, ripping through neighborhoods, streets, valleys, etc., sweeping away whatever is in their path. Flash floods can also occur with a dam or levee failure. Heavy rain should alert you to the possibility of dangerous flood conditions.

Flash Flood Watch

A Flash Flood Watch is issued when conditions look favorable for flash flooding. A watch typically encompasses several counties. This is the time to start thinking about your plan of action and where you would go if water begins to rise.

Flash Flood Warning

A Flash Flood Warning is issued when dangerous flash flooding is happening or will happen soon. A warning is typically issued for a smaller, more specific area. This can be issued due to heavy rain or a dam or levee failure. This is when you must act quickly, as flash floods are an imminent threat to you and your family. You may have only seconds to move to higher ground.

Flash Flood Emergency

A Flash Flood Emergency is issued for the exceedingly rare situations when extremely heavy rain is leading to a severe threat to human life and catastrophic damage from a flash flood is happening or will happen soon. Typically, emergency officials are reporting the rise of life-threatening water, resulting in water rescues or evacuations.

River flooding

River flooding occurs when heavy rain and runoff fill the river basins with water too quickly. Do you live along a creek or river? Find local river observations and flood forecasts on the NWS Advanced Hydrologic Prediction Service webpage.

River flood and flash flood safety rules

Water is a powerful force and should never be underestimated:

• During periods of heavy rains, stay away from flood-prone areas, such as stream beds, drainage ditches and culverts.

• Move to higher ground if flooding threatens your area.

• If you live or work in flood-prone areas, remain alert during periods of heavy rain.

• Be especially cautious at night, as it is harder to recognize flood dangers.

• Never drive your car into water of unknown depth. Most flash flood deaths occur when people drive their vehicles into floodwaters. Remember: Turn around, don’t drown.

• If your vehicle stalls, abandon it immediately and seek higher ground. Floodwater may rise quickly, cover the vehicle and sweep it away.

• Stay out of flooded areas. The water may still be rising and swift. A rapidly flowing stream can sweep you off your feet and sweep your vehicle downstream.

• Children are especially vulnerable and should not be allowed to play in or around flowing water.

• Water can run off streets and parking lots rapidly, causing natural and man-made drainage systems to overflow with floodwaters.

• Floodwaters can hide rocks, trees, trash and other debris that can be dangerous to someone in their path.

Information and graphics courtesy of the National Weather Service.

Read more about Alabama’s Severe Weather Awareness Week and severe thunderstorms.

For more weather news and information from James Spann, Scott Martin and other members of the James Spann team, visit AlabamaWx.