GEOG 111 1st Edition Lecture 36 Outline of Last Lecture I Tornadoes a Characteristics b Super cell thunderstorms Outline of Current Lecture I II III IV V Tornadoes and their attributes a Tornado Strength Tornado development Geographic distribution Seasonal Distribution Tornado damage and safety Current Lecture I Tornadoes and their attributes continued a Tornado strength F 0 to F 6 i As F scale rating increases damage frequency size and duration increase as well 1 Large tornados move the quickest ii Irregular patterns from one year to year iii Strong tornadoes concentrated in tornado outbreaks days with lots of activity iv Weak tornados occur frequently and for a short amount of time v Determining strength 1 Work with structural engineers to assess damage after the tornado vi F 4 and F 5 tornados typically consist of multiple vortices 1 Winds spinning counterclockwise 2 Many tornados are nested within a broader tornado II Tornado development a Wave cyclone circulation counterclockwise b Warm moist air feeding into the system at the warm sector c Directional shear winds are blowing different directions as you go up through the column i Winds are also blowing faster in the upper part of the column d Tornados occur in the warm sector i Instability warm moist air in the lower levels ii Trough approaching cooling of column in middle and top part of the column 1 ELR is steeper so thunderstorms readily develop iii Combine these factors with the wind shear 1 Speed shear causes tornado genesis 2 Rolling wind hits updraft and is translated into the vertical These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute 3 Connect with mesoscale circulation III Geographic distribution i Correlates with terrain ii Need well organized rolls on the surface that s not too rough 1 Mountains and hills inhibit lower level convergence and thunderstorm development 2 Less tornadoes in the western part of the country 3 Maximum in the southern Great Plains a Presence of dry air aloft 4 More tornadoes in North America than other continents a No mountains in the Eastern part that could block warm moist air from the Atlantic and Gulf b No East to West mountain ranges like the Himalayans IV Seasonal distribution a Spring maximum early May i Correlates with jet stream strength position strong winds aloft greater wind shear and instability V Tornado damage and safety a Strong winds and flying debris b Pressure differences produce strong uplift c Stay in an interior room that has no windows and is closed off completely i Bathrooms are a little bit more safe because of the plumbing and greater structural support ii Lowest level of the building d Mobile homes are most deadly i Account for 45 percent of all tornado related deaths e In a car never try to outdrive a tornado i They change directions quickly and can lift up a car and toss it through the air ii Get out of the car as soon as possible and seek shelter in a building if not lie in a ditch away from the vehicle
View Full Document
Unlocking...