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2025 Hazard Mitigation Plan <br />Kittitas County, Washington <br /> <br /> <br />Chapter 4: Hazard Identification and Risk Assessment 190 <br />Daily AQI <br />Color <br />Levels of <br />Concern <br />Values of <br />Index Description of Air Quality <br />Orange Unhealthy for <br />Sensitive Groups 101 to 150 Members of sensitive groups may experience health <br />effects. The general public is less likely to be affected. <br />Red Unhealthy 151 to 200 <br />Some members of the general public may experience <br />health effects; members of sensitive groups may <br />experience more serious health effects. <br />Purple Very Unhealthy 201 to 300 Health alert. The risk of health effects is increased for <br />everyone. <br />Maroon Hazardous 301 or higher Health warning of emergency conditions. Everyone is <br />more likely to be affected. <br />EPA establishes an AQI for five (5) major air pollutants regulated by the Clean Air Act. Each of these pollutants has a natio nal air quality <br />standard set by EPA to protect public health - ground-level ozone, particle pollution (also known as particulate matter, including PM2.5 and <br />PM10), carbon monoxide, sulfur dioxide, and nitrogen dioxide. <br /> <br />When weather conditions are conducive to wildfire ignition, the NWS local Forecast Office issues a series <br />of advisories. Table 4-141 outlines the fire advisories issued by NWS as conditions warrant.244F <br />244 <br />Table 4-141. NWS Fire Advisories <br />Type Definition <br />Fire Weather Watch <br />Issued to alert land managers and the public that upcoming weather conditions (e.g., <br />combination of strong winds and low humidity, dry and unstable air mass, and/or <br />lightning) could result in extensive wildland fire occurrence or extreme fire behavior. It is <br />issued when critical fire weather conditions are possible but not imminent or occurring. <br />Red Flag Warning <br />Issued by NWS, in conjunction with land management agencies, to alert land managers <br />to an ongoing or imminent critical fire weather pattern (e.g., combination of strong winds <br />and low humidity, dry and unstable air mass, and/or lightning). It is issued when fire <br />conditions are ongoing or expected to occur shortly. <br />Extreme Fire <br />Behavior <br />Issued when a wildfire is likely to run out of control. It is often hard to predict because <br />fires tend to behave erratically and sometimes dangerously. To issue this alert, one (1) <br />or more of the following criteria must be met – moving fast (i.e., high rate of spread), <br />prolific crowning and/or spotting, presence of fire whirls, and/or strong convection <br />column. <br />4.6.9.4. Probability and Frequency <br />The probability of occurrence for a wildfire in Kittitas County is high because significant occurrences of <br />this hazard occur annually throughout the County. Additionally, the probability of occurrence for wildfire <br />smoke in Kittitas County is also high, even if the wildfire is occurring outside of the planning area. Kittitas <br />County has, on average, a greater probability of wildfire burning in any given year than 100% of the <br />counties in the United States. Refer to Figure 4-23 for the wildfire likelihood within Kittitas County.245F <br />245 <br />According to the 2023 Washington State Enhanced Hazard Mitigation Plan, the probability of future <br />wildfire related disaster declarations each year is 70% in the State. Since 1970, the frequency of wildfires <br />and number of acres burned has increased significantly in the State of Washington. Wildfires are <br />expected to continue their increase in extent, intensity, and frequency for the entire State, with large fires <br />becoming more likely in central and eastern Washington. Wildfire season is projected to increase in <br /> <br />244 National Weather Service. (n.d.). Understanding Wildfire Warnings, Watches and Behavior. Retrieved from <br />https://www.weather.gov/safety/wildfire-ww. <br />245 Wildfire Risk to Communities. (n.d.). Kittitas County: Wildfire Likelihood. Retrieved from <br />https://wildfirerisk.org/explore/wildfire-likelihood/53/53037/.