Flooding can be a Major Problem Across Colorado

Colorado 2014 Flood Safety and Wildfire Awareness Week:  Flooding

Today’s topic during this Flood Safety and Wildfire Awareness Week is flood which develops in the time frame of longer than six hours to several days.

Flood History

There have been some notable floods across the Centennial State:

  • In early June of 1921 a flood along the Arkansas River devastated the city of Pueblo. Estimates of drownings ranged from over 100 to over 300 people.
  • Around Memorial Day 1935 catastrophic flooding occurred on the Palmer Divide and the Colorado Springs area causing millions of dollars of damage and killing at least 18 people.
  • The mid-June 1965 flood was widespread across eastern Colorado taking several lives and causing over $500 million of damage.
  • During late April and early May of 1999 after up to 14 inches of rain fell a major flood occurred across southeast Colorado from Colorado Springs to La Junta.
  • Just last year the historic rains and floods in September caused over $3 billion of damage and took 10 lives, including nine community members and one recovery worker.

Floods in Colorado can result from rapid snow melt, a combination of snow melt and heavy rain, or just heavy rain.

National Weather Service forecast offices in Colorado closely collaborate with regional river forecast centers that monitor the Colorado River, South Platte River, Arkansas River and Rio Grande to come to a consensus on the likelihood of flooding along rivers and large creeks.

The National Weather Service will discuss flood potential in Hydrologic Outlooks, Daily Hazardous Weather Outlooks and in Graphical Weather Stories on National Weather Service forecast office web sites.

Hydrologic statements may be issued for high flows that are within the banks of a river or large creek.

When flooding is possible on a river or large creek a flood watch will be issued meaning flooding is possible within the designated watch area.

When flooding is likely or occurring on a river or large creek a flood warning will be issued meaning flooding is expected or has been reported at designated river forecast points.

Flood advisories may be issued for minor flooding on rivers and creeks.

An areal flood warning may also be issued for flooding on a river or large creek in areas away from the designated river forecast points.

You can easily monitor potential flooding along rivers in Colorado and large creeks using the advanced Hydrologic Prediction Service Monitoring System.

Information on this monitoring system can be obtained from Http://www.nws.noaa.gov/floodsafety/ahps.shtml

This monitoring system can be accessed on Colorado National Weather Service forecast office web sites from the left hand menu by clicking rivers and lakes under the Hydrology banner.

At each river and large creek gauge you can easily look at current and forecast water levels, flood categories, historic crests and flood impacts. Probabilities of exceedance of certain water levels by week or over the long term are also available.

In general, there will be some time to prepare for river and large creek flooding and emergency management in your area has plans in place to address the flooding issues. Know these plans and how you should act accordingly when flood watches and flood warnings are in effect.

For more information on flood safety go to: Http://www.floodsafety.noaa.gov

The topic for tomorrow is life-threatening flooding which occurs very quickly - flash floods.

Flood Safety and Wildfire Awareness Week continues through this Saturday.

This blog written by Tom Magnuson, Warning Coordination Meteorologist, National Weather Service Pueblo