Friday, September 18, 2015

The Furture of Flash Flood Warnings

Heavy downpours and flash flooding events continue to increase in different areas of the United States. These specific type of events have increased between 10-40% in the Mid South since 1958. (Kentucky 16%, Tennessee 14%, Missouri 38% and Illinois 12%.)

We don't have to look back too far in the records for our last event. Local businesses and homes were damaged from rushing flood waters when when over 6" of rain fell in 2-3 hours over parts of Paducah, KY.
The heavy rain and storms began around 3AM and came to an end just before sunrise. Streams and creeks were overwhelmed along with an inundated urban development area. Flood zones were filled several inches, even feet deep, and only took a few short hours to dry out. The damage was already done to hundreds of homes/businesses. Many factors came together for this event to become a disaster for many. Most people were asleep when the event began to unfold. There were very few eyes to report the magnitude of the flooding to the correct agencies so they may respond. The rapid nature and timing of the event made it more difficult for community agencies and the general public to react. We've seen similar scenarios across the US, especially with overnight events. 

Click to Enlarge

Back to the reason for this post... as flash flooding and heavy precipitation events rise in frequency, and technology improves to allow for faster response, I feel it is only logical to look at evolving the way we warn the general public. Obviously it's not my job to make these changes but my purpose here is to get a conversation started. If it helps with improving community preparedness and response, I think it's worth it. The National Weather Service has successfully made this change with tornado warnings now issued with emphasis on impact. To see an example, see graphic to the left or click the link to make it larger.
A Flash Flood Warning was issued after reports of major flooding were received and after 3-4", locally more, of rain had fallen (per radar).  Multiple evacuations/water rescues were conducted and many vehicles had to be abandoned. An Urban and Small Stream Flood Advisory would not have been enough in this case and the Flash Flood Warning was needed even sooner despite little verification. As a broadcast meteorologist, it makes it difficult to put weight behind a specific threat without the National Weather Service. I would love to see the dissemination process for flash flood warnings look more like our modern impact based tornado warnings.

Impact Based Flash Flood Warnings (3 Types):

  • Flash Flood Warning: Radar Estimated or Observed
  • Flash Flood Warning: Imminent or Ongoing Threat
  • Flash Flood Warning: High Risk to Life/Property; State of Emergency

The National Weather Service provides services and products that broadcast meteorologists cannot perform their jobs without. Collaborating and depending on one another is the only way to prepare and protect the communities that we serve. In the spirit of community preparedness, it's worth it to look at evolving and improving Flash Flood Warnings, and possibly eliminating Urban/Small Stream Flood Advisories.  Flash Flood Warnings don't always lead to life threatening situations but become necessary when Urban and Small Stream Flood Advisories are not as efficient in informing the public.
Send me your thoughts and opinions...I'd to love to hear them! Email Me. 

To see your state trend and local impacts from increased heavy rainfall events, take a stroll through this interactive map: