Good afternoon, F2P2 program participants.
We are hoping to get some feedback about the
UDFCD Heavy Rainfall Threat Analysis (hereafter, Tool), which is part of our F2P2 program that operates from May to September. This quick survey will help us gain knowledge about the
Tool’s popularity as well as how the community is using it. Should you want more information about the Tool, you can provide an email address at the end of the survey. Keep reading below if you’d like a description of the Tool. Thank you for your time!
Click here to be directed to the survey:
https://www.surveymonkey.com/r/SDH3WXY
Best,
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Dana McGlone, Project Meteorologist
720.943.5923 (office)
303.921.5999 (cell)
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Kevin Stewart, P.E.

Manager | Flood Warning & Information Services
URBAN DRAINAGE AND FLOOD CONTROL DISTRICT
50th ANNIVERSARY
2480 W. 26th Ave Suite 156-B | Denver,
Colorado 80211
Office: 303-455-6277 | Direct: 303-749-5417 | www.udfcd.org
Protecting People, Property, and the
Environment
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The UDFCD Heavy Rainfall Threat Analysis (hereafter, Tool) creates probabilistic
Quantitative Precipitation Forecasts (QPF) over five forecasts zones in the Denver Metro Area by ingesting several high-resolution atmospheric models. Real-time operations began in 2015, and the Tool updates three times daily
during the warm season from May 1 to September 30. Urban and topographic flooding can be triggered with rainfall intensities as low as 1 inch per hour, which are common over the area during the warm season. The Tool was generated to address the following questions
on heavy rainfall days:
As mentioned, the Tool combines 4-km resolution atmospheric models from several government agencies (NCEP, NCAR and NSSL). These models provide higher resolution QPFs than
currently available from federal agencies. To further improve forecast reliability, the QPF is post-processed using ALERT rainfall data. The use of many models allows us to determine the probability, and thus confidence, of heavy rainfall occurrence. The Tool
has been able to accurately anticipate the highest observed rainfall rates over 85% of the time. An average miss rate below 6% ensures that virtually all heavy rainfall events are captured. The Tool
is also able to distinguish as to whether the heavy rainfall threat will occur in the foothills, downtown Denver or the eastern Plains. This is critical for supporting Emergency Managers and other stakeholders that use the
information for decision support.
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We thank you in advance for your participation in this survey.