Severe Weather What creates it, what it means, and how to stay safe Table of Contents Overview Heavy Rain & Floods High Winds (Bow Echoes & Derechoes) Lightning Hail Tornadoes Hurricanes and Tropical Storms Weather threats Watches and Warnings High winds Strong winds above the ground are drawn downward within the storm This helps to create a gust front and causes the storm to accelerate and bow out Winds create a feedback system with a main flow behind storm (rear inflow jet) and rotation on the ends (bookend vorticies). Tornadoes: Distribution vs. Deaths Most US tornadoes occur in tornado alley (TX, OK, KS) But the frequency of killer tornado events in highest in the southeast (AR, TN, MS, AL) A warning on statistics BE CAREFUL WITH AVERAGES! One year of data can strongly skew averages Hurricane fatalities 2005: 1016 fatalities , : 123 fatalities (14 per year) 10-year avg: 114 fatalities per year Tornado fatalities 2011: 553 fatalities : 522 fatalities (58 per year) 10-year avg: 108 fatalities per year It is generally safer to use averages over longer periods But shorter average times have uses as well Watches and Warnings Weather watch Conditions are favorable for development i.e. it COULD happen E.g. a strong cold front moving into warm, moist air creates the chance for strong thunderstorms, so a Severe Thunderstorm Watch may be issued Weather warning The weather event is HAPPENING or is IMMINENT E.g. authorities have spotted a tornado OR weather radar indicates strong rotation within a storm, so a Tornado Warning will be issued Conclusion of sample presentation Please contact us if youd like to see this entire presentation: The complete presentation can be used for free by most educational interests and organizations. Please contact us if youd like to use it. See the website for more presentations! www.route283east.com/resume/presentations weather.route283east.com/presentations education.route283east.com/presentations