Ann Arbor, Michigan is a located southwest
of Detroit on the Huron River in an agriculturally productive area. The elevation ranges from 750 feet-1,000 feet. Parts of the city are densely forested and surrounded by grasslands and croplands. The estimated Bowen Ratio for Ann Arbor would be around .6 due to the humid continental climate and physical geography.
Ann Arbor experiences
consistent atmospheric stability with cold winters and warm summers. Average summer
highs reach the mid-80s in late July and average winter lows are in the teens
around mid-January. Consistent with most of the northeast, Michigan has prominent
seasons. The warm season lasts from May through September with an average high
daily temperature above 72°F, while the cold season occurs from November
through March with an average high daily temperature below 40°F.
Temperature averages in Ann Arbor over the last thirty years:
Cloud cover is consistent with the seasons; the more clear time of
the year begins on March 20th while the cloudier part of the year
begins in late October.
Cloud cover in Ann Arbor over the last ten years:
Because Michigan is surrounded on three sides by the
Great Lakes, proximity to
water has some consequences for the area. For example, cool air from Canada moving across the Great Lakes will cause water to evaporate. The vapor then cools and condenses into
clouds. Once over cool land, clouds will produce snow on
the shore or inland. This is referred to as the "Lake Effect."
Interesting animation of the Lake Effect:
http://svs.gsfc.nasa.gov/vis/a000000/a001200/a001271/a001271.mpg
Wind can influence weather patterns in the Ann
Arbor area, especially in terms of the Lake Effect. The city experiences wind speeds from 0 to 16 mph (calm to moderate
breeze). For the most part, wind blows in the south or southwest direction,
bringing weather to the city from over Lake Erie and sometimes Lake Huron.
Wind directions in Ann Arbor over the last ten years:
Precipitation is somewhat predictable;
the highest probability of snow occurs during the cold season and the highest
probability of thunderstorms occurs during the warm season.
Probability and types of precipitation in Ann Arbor over the last ten years:
Overall, light snow
is the most common form of precipitation. Although cloud coverage lessens during the summer months, the warm season experiences the most
precipitation with around 3.5 inches per month from thunderstorms, while the cold season receives
between 2.5 and 3 inches per month from light snow. There is no dry season for the city. Over
the last 30 years, the mean annual total precipitation was 37.4 inches. Snowfall during the winter ranges from moderate to heavy. The highest amounts of snowfall occur during December through February.
Common precipitation types in Ann Arbor over the last ten years:
Overall average amount of precipitation in Ann Arbor over the last thirty years:
Ann
Arbor is located in the cP air mass, or continental polar air mass. This air
mass is cold and dry due to its origins over inland Cananda. However, Ann Arbor is a fairly humid area due to its proximity to the Great Lakes. There is some potential for severe
weather for the city. Tornado activity is significantly above average compared
the rest of the state of Michigan, and well above average compared the United
States. Earthquake potential is also slightly above average in comparison to
the rest of the state and United States.
Michigan State Theater in Ann Arbor during a snow storm:
Resources:
http://www.ncdc.noaa.gov/cag/
http://www.ncdc.noaa.gov/oa/climate/normals/usnormals.html
http://svs.gsfc.nasa.gov/vis/a000000/a001200/a001271/a001271.mpg
http://weatherspark.com/averages/29652/Ann-Arbor-Michigan-United-States
http://glisa.umich.edu/docs/AnnArborMI_Climatology.pdf
http://www.weather.com/weather/wxclimatology/monthly/graph/48109
http://www.x98ruhf.net/lake_effect.htm
http://weatherspark.com/averages/29652/Ann-Arbor-Michigan-United-States
http://markbialek.com/ann-arbor-nights-snowstorm-shoot/
