Time: 418 PM Sat May 15, 2021 Forecaster: Brad Simmons

Flash Flood Prediction Program


We have determined that street and small stream flooding is possible in the following counties: Boulder (City of Boulder affected, Four Mile Burn Area affected), Jefferson, Broomfield, Adams, Denver
including: DIA, Arvada, Wheat Ridge, Lakewood
from: Current to 900 PM.
Prime time for flooding: Current to 800 PM.
Forecast rainfall: Moderate to strong thunderstorms will have the potential to produce 0.3-0.8" of rain in 10-30 minutes. A nearly stationary thunderstorm may result in up to 1.6" of rain in 60 minutes or less.
The most likely areas to be impacted by flooding are:

X Urban streams/gulches; road crossings; recreational trails; adjacent open space areas/campgrounds/parks; floodplain properties; utilities

X Urban streets, intersections, low lying areas, known trouble spots

X Mountain locations subject to mud/rock/debris slide

Additional Information: Strong thunderstorms may also contain large hail, gusty winds, frequent cloud-to-ground lightning.

This message is not intended for public dissemination. Please pass this information along to affected emergency response organizations (police, fire, public works, etc.) within your area.

Also, please take appropriate actions to prepare for possible flooding.

Further information will be provided to you as it becomes available.