National Weather Service United States Department of Commerce

Wisconsin Tornado and Severe Weather Awareness

Flash Floods -

In the past 30 years, flooding has typically been the number one thunderstorm-related killer in the United States.  The number of flood-related deaths goes up and down each year, however the recent trend has been down.  For the period of 1988-2012, there was an average of 80 fatalities each year due to the direct results of flash flooding and flood events across the United States.  In 2012, there were 28 flood-related fatalities in the U.S.

How flash floods form and what they can do -

Flash floods can occur as the result of heavy rains falling over a short period of time, usually only a few hours or less. They can be caused by ice jams on rivers or even a dam or levee break.  The sudden buildup of water can cause a large crest of water to move quickly downstream, wiping out most everything in its path.  Flash floods are capable of rolling boulders, tearing out trees and destroying buildings quickly with little or no warning. 

Flooding is considered one of the most common and widespread of all natural disasters.  It can occur just about anywhere, and Wisconsin is certainly not immune from this type of disaster.

Wisconsin has many landmarks, both man-made and natural that make these areas more susceptible to flash flooding. For instance, Wisconsin has many old earthen dams which are getting weaker every year.  If one of these dams were to break, the areas around them would be threatened by flash flooding.  For safety's sake, find out if there is an earthen dam in your area.

Flash flooding due to ice jams is very common in Wisconsin since Wisconsin usually has long and cold winters, and rivers almost always freeze over.  A sudden wall of water released when an ice jam breaks during a thaw can be extremely unpredictable and can happen very quickly.  Always monitor the situation in your local area.

Turn Around, Don't Drown -

Flash floods kill dozens of people in their vehicles each year.  As little as six inches of fast-moving water can move your vehicle and two feet of water is enough to float your vehicle.  Avoid flooded bridges and never drive through flooded roadways.  Turn around, don't drown.  Be especially cautious at night when it is harder to recognize flood dangers.

When a flash flood is headed your way, you may only have seconds to save your life.  Abandon all personal property and flee to higher ground if a flash flood is approaching. Any delay, even for a second, could be the difference between life and death.

Flash Flood Watches -

A flash flood watch is issued when an area prone to flash flooding is threatened by very heavy rains.  During a flood watch, residents should be alert for signs of rising water and be prepared to flee to higher ground immediately.  It is possible that there will be no time for an additional warning.

Flash Flood Warning -

The National Weather Service issues a flash flood warning when a flash flood is occurring or is imminent in a specific area.  When a warning is issued, get out of the danger area and head to higher ground immediately.

A few words for campers -

Campers, if you are planning to set up camp near a stream, be sure to place your camp well above the stream level.  It is also a good idea to plan an escape route in advance should a flood occur.  If you are in a steep valley or canyon, do not try to outrun the flood.  Leave your equipment and personal belongings and climb to higher ground.

Being alert for flash floods -

Most importantly, always monitor the weather conditions in your area if flash flooding is a threat where you are located. Stay tuned to your local TV and radio stations, including NOAA Weather Radio All-Hazards for the latest information on watches and warnings in your area.

Additional Flash Flood Information -

Get more information flood safety and awareness here: