Climate and Weather

Yellowstone National Park is located primarily in the north east corner of Wyoming but it extends into parts of Idaho and Montana. The mountain ranges and changes in altitude contribute to the climate, which is why the climate encompasses Semiarid (Midlatitude) Steppe climate (BSK) and Highland climate (H).

http://printable-maps.blogspot.com/2008/09/climate-maps-united-states-and-canada.html


Insulation, angle of incidence, global wind patters, air masses and altitude all affect climate, the primary factor in temperature and precipitation of a region. The parks' summer diurnal temperatures are pretty variable and range from highs in the 70s/80s to lows below freezing, especially at higher altitudes. Winters are very cold and the highs/lows stay from below zero to about 20 degrees most of the winter. Precipitation is also variable and ranges from 15 inches annually to 80 inches in the southwestern part of the park.

The climate of Yellowstone is similar to that of Denver, hot and dry summers and wet winters. Yellowstone has colder winters though and more severe temperature swings than Denver. 
http://www.wrcc.dri.edu/pcpn/us_precip.gif

One form of precipitation is convection, which is a major cause of weather phenomenon like thunderstorms. Weather has vast impact on humans; floods, lightning and tornadoes are among the leading causes of weather fatalities. Tornadoes in Yellowstone are rare, but on July 21, 1987, the highest altitude tornado ever recorded in the US raged up and down the mountains in the park.

The F4 left a 24-mile long, 1.5-mile wide path of destruction, uprooting up to 1,000,000 trees over 15,000 acres. Wind speeds were estimated at between 207 and 260 miles per hour.
http://www.qwiki.com/q/#!/Tornado_Alley


http://en.wikipedia.org/wiki/Yellowstone_National_Park#Climate
http://en.wikipedia.org/wiki/Teton%E2%80%93Yellowstone_tornado
http://www.yellowstone-natl-park.com/weather.htm