Item 26 - Adoption of the City of Santa Ana Emergency Operations Plan

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City of Santa Ana Emergency Operations Plan Part I Basic Plan National Weather Service Products and Information Orange County's weather forecasts are provided by the National Weather Service San Diego Weather Forecast Office (NWS-San Diego). There are three National Weather Service Zones in Orange County. It is important to understand Orange County weather zones, as weather forecasts may not affect all of Orange County in the same way. For example, it may be cooler along the coast than in inland Orange County. These forecast zones are: Orange County Coastal covers the immediate coastal region, including beaches and coastal cities west of I- 405 and the southern portion of I-5. Orange County Inland includes the inland coastal valleys and plains of Orange County, mainly east of I-405 and including most of the I-5 corridor. The City of Santa Ana lies in the Orange County Inland zone. Santa Ana Mountains and Foothills includes the Orange County unincorporated canyon areas and Cleveland National Forest areas in South Orange County. The National Weather Service issues a variety of Hot Weather notices when temperatures are forecast to be unusually high. The guidelines for these notices in Orange County are: A Heat Advisory is issued within 48 hours of the onset of a short -duration heat event when daytime temperatures are well above average but the temperature cools at night. A Heat Advisory is issued for the Orange County Inland zone when temperatures are forecast to exceed 100 degrees for one to three days in more than one city. An Excessive Heat Watch is issued when there is a potential for an Excessive Heat Warning to be issued within the next 24 to 72 hours, but the exact timing and occurrence are still uncertain. An Excessive Heat Warning is issued within 48 hours of a longer -duration heat event of 3 days or more. An Excessive Heat Warning is issued for Orange County Inland when ambient air temperature will meet or exceed 105 degrees, or the Heat Index (see below) will exceed 110 degrees. These sustained heat events, with less cooling opportunity for people to recover from heat effects, result in more cumulative health impacts. Heat Vulnerabilities and Risk Factors Heat Index — The Heat Index captures how hot the combination of air temperature and relative humidity feels to people. As humidity increases, the air seems warmer than it is because the body is unable to cool itself by evaporation of perspiration. As the Heat Index rises, so do health risks. In Southern California, we experience less humidity in our weather, so air temperature is the dominant factor. 58