Emergency Plan Manual

24 FLORIDA STORM WATCH SEVERE THUNDERSTORMS What Makes a Severe Thunderstorm? Although every thunderstorm in Florida has the potential to cause death, about 10% produce dangerous winds or hail that will likely exceed thresholds known to cause significant damage to well-built structures or cause bodily harm. These area known as severe thunderstorm. Severe thunderstorm produce hail the size of a dome or larger and/or winds of 58 miles per hour or treater. Where Are Severe Thunderstorms Likely to Occur? On overage, the interior sections of central Florida receive the most thunderstorms with nearly 100 plus days per year. However, thunderstorms are also frequent along coastal areas which average 80 to 90 days per year. Although Florida thunderstorms are generally less than 15 miles in diameter, they can grow vertically to great heights in excess of 10 miles high into the atmosphere. This stacking effect of concentrated moisture can explain why a Florida thunderstorm directly overhead could produce four or more inches of rain in less than an hour while a location a few miles away may see only a trace. Where Can You Go For Up-To-Date Info? * Day 2 Convective Outlook - Issued twice a day to outline the where severe thunderstorms may develop and qualifies the degree of risk (i.e. SLGT, MDT, and HIGH risk areas). * Day 1 Convective Outlook - Issued 5 times daily to outline the areas where severe thunderstorms may develop and qualifies the degree of risk (i.e. SLGT, MDT, and HIGH risk areas). * Hazardous Weather Outlook - Issued daily by local NWS offices to advise storm spotter and emergency managers of potentially hazardous weather and other hazards. * Severe Thunderstorm Watch - Issued to alert the public that conditions are favorable for the development of severe thunderstorms in and close to the watch area. These watches are issued with information concerning the watch area and the length of time they are in effect. * Short Term Forecast - Issued as a 1-2 hour forecast of local weather conditions; emphasizing hazardous weather. * Severe Thunderstorm Warning - Issued by local NWS offices to warn the public that a severe thunderstorm has been sighted by storm spotters or has been indicated by radar.