Laserfiche WebLink
2024 Hennepin County All -Jurisdiction Hazard Mitigation Plan <br />Volume 2 — Hazard Inventory <br />Current/valid Excessive Rainfall Outlooks can be found at: http://www.wpc.ncep.noaa.gov /qpf/ excess <br />rain.shtml <br />Within 48 hours: Chanhassen NWS Office issues Flash Flood Watch, based on combination of expected <br />precipitation and local Flash Flood Guidance values. <br />Important: In early spring 2018, the NWS will no longer use Flash Flood Watches, and will <br />instead consolidate them into generic Flood Watches, as part of its Hazard Simplification <br />process: https://www.weather.gov/news/170307-hazard-simplification <br />Within 1-6 hours: WPC issues Mesoscale Precipitation Discussion to highlight emerging flooding potential <br />from expected, developing, or ongoing thunderstorm and rainfall activity. These discussions are only used <br />for large areas of concern (generally the size of 25 or more Minnesota counties) and do not pertain to <br />highly localized extreme events. <br />Each discussion includes an annotated graphic indicating the area of concern, and a brief text discussion <br />focused on the mesoscale features supporting the anticipated heavy rainfall. The potential for flash <br />flooding within the area of concern will be highlighted by one of three headlines: <br />FLASH FLOODING LIKELY High confidence exists that environmental conditions are favorable, or <br />will become favorable, for heavy rainfall that will result in flash flooding. <br />FLASH FLOODING POSSIBLE Environmental conditions are favorable, or will become favorable, for <br />heavy rainfall, but there are questions about how the event will evolve and/or whether flash <br />flooding will occur. <br />FLASH FLOODING UNLIKELY High confidence exists that environmental conditions are <br />unfavorable, or will become unfavorable, for heavy rainfall that will result in flash flooding. <br />Once event has begun: Chanhassen NWS Office issues Flash Flood Warning, based on combination of <br />precipitation received, further precipitation expected, soil conditions, and stream levels and flow. A Flash <br />Flood Warning is issued when flash flooding is occurring or is imminent. These warnings differ from Severe <br />127 <br />