History of Flash flood warning in Timeline

A flash flood warning is a critical alert issued by weather agencies globally, indicating an imminent or ongoing flash flood. These floods are characterized by their sudden and violent nature, typically triggered by heavy rainfall or, less frequently, dam failures. Several factors influence the likelihood of flash flooding, including the intensity and duration of rainfall, the topography of the land, soil conditions, and the type of ground cover present.

August 27, 2017: Flash Flood Emergency Issued During Hurricane Harvey

On August 27, 2017, during Hurricane Harvey, the NWS issued a "Flash Flood Emergency for Catastrophic Life Threatening Flooding" in southeast Texas due to torrential rain.

September 10, 2017: Flash Flood Emergency Issued During Hurricane Irma

On September 10, 2017, the NWS issued a Flash Flood Emergency for life-threatening storm surge because of Hurricane Irma in southwestern Florida at the eye landfall.

February 6, 2020: Flash Flood Emergency for Tazewell County, Virginia

On February 6, 2020, the NWS issued a Flash Flood Emergency for Tazewell County, Virginia, due to a major storm that caused the Clinch River to rise to its highest crest in 40 years.

May 20, 2020: Flash Flood Emergency for Tittabawassee River

On May 20, 2020, the NWS issued a Flash Flood Emergency for the Tittabawassee River in Midland County, Michigan, due to multiple dam failures, causing the river to overflow and reach its highest crest since 1986.

July 6, 2020: Flash Flood Emergency for Tacony Creek and Frankford Creek

On July 6, 2020, the NWS issued a Flash Flood Emergency for Tacony Creek and Frankford Creek, the former situated along Montgomery County and North Philadelphia, Pennsylvania, and the latter along Philadelphia's Frankford neighborhood.

September 2, 2021: First Ever Flash Flood Emergency for New York City and surrounding areas

On September 2, 2021, the NWS issued a first-ever Flash Flood Emergency for New York City, Philadelphia, Fairfield and New Haven Counties in Connecticut, and most of Central New Jersey. The region stretches over 200 miles, as the remnants of Hurricane Ida transitioned and intensified into a post-tropical cyclone causing torrential rains.

July 28, 2022: Flash Flood Emergencies in eastern Kentucky

On July 28, 2022, the NWS issued several Flash Flood Emergencies in eastern Kentucky for catastrophic and deadly flooding.

March 27, 2023: Flash Flood Emergency for Head's Creek Reservoir Dam Break

On March 27, 2023, the NWS issued a Flash Flood Emergency for a dam break on the Head's Creek Reservoir in Spaulding County, Georgia. A statement was later posted on Twitter.

September 27, 2024: Flash Flood Emergency for Metro Atlanta during Hurricane Helene

On September 27, 2024, a Flash Flood Emergency was issued for Metro Atlanta as Hurricane Helene brought catastrophic flooding to the area.

October 9, 2024: Flash Flood Emergency for Tampa Bay and Big Bend areas during Hurricane Milton

On October 9, 2024, a Flash Flood Emergency was issued for several counties in the Tampa Bay and Big Bend areas of Florida as Hurricane Milton posed life-threatening flooding to a large portion of the West Coast.

April 2025: Flash Flood Emergency and Particularly Dangerous Situation Wording

In April 2025, a warning containing both the "Flash Flood Emergency" wording and the Particularly Dangerous Situation wording was issued during a severe weather event impacting parts of the central and mid-southern United States.