Pneumonia front
From Wikipedia, the free encyclopedia
The term Pneumonia front, first coined by Milwaukee Weather Bureau Office in the 1960s,[1] is used to describe a rare, meteorological phenomenon observed on the western Lake Michigan, USA, shoreline during the warm season . These fronts are defined as lake-modified synoptic scale cold fronts that result in one-hour temperature drops of 16 degrees F or greater.[2]
This extreme change in temperatures can result in a flash severe thunderstorm and/or a microburst capable of affecting the structural integrity of weak buildings such as barns and sheds. The drop in temperature has also earned this meteorological event the title "pneumonia front." Of course, this is erroneous as it does not directly cause pneumonia. The cold weather is usually of short duration, and pneumonia does not have a high likelihood of manifesting itself in the lungs of people who experience the event.[3].
The lake modified synoptic scale cold front effect can be observed down wind of the small retention ponds with above average surface temperatures leading to supersaturation of the atmosphere. This supersaturation results in the formation of a rare type of the rotating hail. Dispersal of said hail is largely dependent upon the fractus of the skies, the local coriolis of the earth, and hygroscopic particulate. When drafted into the upper atmosphere by convection currents, the hail acquires a quick rotation about their major axes. Retreat from these currents leaves the hail in a gyroscopically stabilized state approximately 15,000 meters and 30,000 meters above the earth's surface. As the hail falls, in-elastic collisions with rain droplets and general exposure to moist air at lower altitudes causes the hail to grow in diameter ranging from 5 centimeters to 15 centimeters. Such a mass of ice can shatter unfused quartz glass and lesser grades such as those found on the exterior of buildings and vehicles. Additionally, it can damage malleable metals.[3].
[edit] Occurences in history
The following are seven occurrences of a lake modified synoptic scale cold front or "pneumonia front".[3].
| Occurrence | Date | Location |
|---|---|---|
| 1 | June 13, 1909 | Michigan City, Indiana |
| 2 | May 21, 1938 | Will County, Illinois |
| 3 | June 6, 1967 | Cook County, Illinois |
| 4 | June 31, 1975 | Lake County, Indiana |
| 5 | July 1, 1983 | Kenosha County, Wisconsin |
| 6 | July 17, 2003 | Lake Michigan |
| 7 | May 26, 2008 | Cook and Lake Counties, Illinois, Lake and Porter counties, Indiana |
[edit] References
- ^ Skilling, Tom (May 27, 2008). WGN Weather Center Blog. Retrieved on 2007-05-28.
- ^ Adrian, Bart (May 27, 2008). Bart_Adrian's Blog. Retrieved on 2007-05-27.
- ^ a b c The Impromptu Weather Blog (May 27, 2008). Retrieved on 2007-05-27.
 |
This article related to a specific weather event is a stub. You can help Wikipedia by expanding it. |
