2 Severe Weather Safety Watches- conditions are favorable Warnings- conditions already existExamples- Tornadoes, Flooding, Thunderstorms, Blizzards, Winter Mixes and Hurricanes
3 How Thunderstorms Form For a thunderstorm to form, three conditions must exist.Thunder, Lightning, Rain, High WindsPossibly Hail, Tornadoes1. There must be an abundant source of moisture in the lower levels of the atmosphere.2. Some mechanism must lift the air so that the moisture can condense.The portion of the atmosphere through which the cloud grows must be unstable.
5 Lightning and ThunderLightning – discharge of electricity from a t-cloud to ground, to another cloud, or from the ground to a cloudExtremely high temp., air expands explosively – causes thunderLight travels faster than sound – causes delay between lightning and thunderThunder can be heard up to 16 kmMr. ErtlEarth Science
8 TornadoesNarrow, funnel shaped-column of spiral winds that extends downward from cloudOccur more frequent in US than anywhere elseMississippi River Valley and Great PlainsGrow out of T-Storms, produced when cold, dry air meets warm, moist airWinds between km/hourUsually travel SW to NEMr. ErtlEarth Science
9 Intensity measure on Fujita Scale The scale ranges from F0, which is characterized by winds of up to 118 km/h, to the violent F5, which can pack winds of more than 500 km/h.Mr. ErtlEarth Science
14 Formation of Hurricanes Hurricane seasons starts June 1 – November 30A tropical disturbance forms.Has to form near the equator over water.The warm air rises and cool to form clouds.Forms large intense low pressure system.Winds reach 23 mph tropical depressionWinds reach 39 mph tropical stormReceives a nameWinds reach 74 mph hurricane
15 How to Name a HurricaneEach time a storm reaches tropical storm status it receives a name.Name are picking from a list in alphabetical order.
16 Classifying a Hurricane Use the Saffir- Simpson ScaleBased on a 1-5 scale.1 being the least amount of damage.5 the most amount of damage.