April 2008 Newsletter

The next SKYWARN meeting is at the Owatonna Fire Station on 15-Apr @ 7:00 PM, the third Tuesday of the month.

MN SKYWARN Workshop From MN SKYWARN Workshop
Join storm spotters from across the state for the 3nd annual Minnesota Skywarn Workshop on 05-Apr. The full-day severe weather conference in St. Paul is designed to train you in spotting techniques, equip you with information about the latest in weather technology. You will also be able to connect with other Skywarn communities from across the state. The pre-workshop registration fee is $10. On-site registration will not be available.

March Meeting Notes
Approximately 12 people attended the 18-Mar meeting. The highlight was a mock deployment. Participants also learned some radar techniques while watching some severe weather develop in the south.

NOAA Weather Radio
The 08-Mar WX Radio Event was a resounding success. Additional details and pictures are posted in the Archives.

SKYWARN Training
Karen Trammell KD5PTI and Meagan Schwitzer from the National Weather Service at Chanhassen came to Owatonna on 13-Mar to provide SKYWARN Spotter Training. There were over 55 participants filling the room to capacity. Many took the time to sign on with the NWS to acquire NWS Spotter ID Numbers. The presentation was updated from the previous year and even everyone took away something new. Certificates were awarded to all.

Storm Presentation
Dave Purscell presented a program on "How to prepare for 2008 Storm Season" at the Elks Club on 19-Mar. About 60 people were in the lunch buffet learning how to identify storm shelters, plan and practice tornado drills, receive alerts, and general weather awareness.

Animal Weather Predictions From NASA
After discussing Groundhog Day last month, you can find a number of cases where animal folklore contains a grain of scientific truth. See how well you do with these bits of folklore -- True or False:

  1. Geese (and other migrating birds) fly higher in fair weather than in foul.
  2. Sea gull, sea gull, sit on the sand; It's a sign of a rain when you are at hand.
  3. A cow with its tail to the west, makes weather the best. A cow with its tail to the east, makes weather the least.
  4. If corn husks are thicker than usual, a cold winter is ahead.
  5. The higher the clouds, the better the weather.
  6. When ants trave in a straight line, expect rain; when they scatter, expect fair weather.
  7. Flies bite more before a rain.
  8. Sun or moon halos indicate a coming rain (or snow): the larger the halo, the nearer the precipitation.
  9. Bees will not swarm before a storm.
  10. Crickets are accurate thermometers; they chirp faster when warm and slower when cold.
  11. When leaves show their backs, it will rain.
  12. When the ditch offends the nose, look for rain and stormy blows.
  13. When smoke descends, good weather ends.
  14. When squirrels lay in a big store of nuts, look for a hard winter.
Answers appear below.

Early MN Tornadoes From Minnesota WeatherTalk
The earliest recorded tornadoes in MN are:

  • 18-Mar-1968: At 5:30p, a F-2 tornado (winds to 157 mph) traveled for 6 miles across Watonwan County near the town of Truman.
  • 20-Mar-1991: A F-1 tornado (winds to 112 mph) touched down in Faribault County 3 miles south of Bricelyn around 4:30pm. It traveled northeast toward Wells for about 15 miles.
  • 21-Mar-1953: Traveling 11 miles, an F-2 (winds to 157 mph) crossed portions of Stearns and Benton Counties,

Atlanta Tornado From Several Sources
The severe tornado that hit Atlanta seems to be unusual that it hit a large central business district. There are three possible reasons for that:

  1. The central city may produce a "heat island" in which turbulent rising air disrupts the formation of small tornadoes. Professor Fujita of the University of Chicago suggested that the "heat island" effect takes hold for small tornadoes when a city reaches a population of about 1,000,000.
  2. The "roughness" created by the skyscrapers causes turbulence that disrupts the formation of small tornadoes. It is possible that a tornado could actually intensify even more after it forms outside of town and moves into the central city. One speculation has it that the friction of the buildings will slow down the inflow of air into the funnel. This would deprive the funnel of air. The pressure would drop, causing the funnel to shrink in diameter, and spin even faster.
  3. The idea that tornadoas are rare, and the central city is very small. So it is a matter of coincidence. The chance of any particular tornado hitting a major downtown is quite low -- not for any meteorological reason, but simply because downtowns are small targets. Even when tornadoes hit metro areas; their odds of hitting downtown are small out of space considerations alone.

The downtown areas of "big cities" have had tornadoes on occasion. Atlanta was the sixth tornado to hit the central business district of a major U.S. city in the past 10 years. Others include Jacksonville, Fla., Fort Worth, Texas, Salt Lake City, Little Rock and Nashville.

Nighttime tornadoes are dangerous because they're hard to see and because unsuspecting people are asleep when they hit. The fatality rate is 64% higher than those that strike during daylight hours. They're hard to photograph, but one photographer captured this photo. The tornado is the light-gray vertical column to the right of the building and to the left of the scud clouds.

Tornado Sounds From CNN
People often indicate that a tornado sounds like a train. This CNN video is a meteorologist trying to explain why.

Climate Prediction Center From Minnesota WeatherTalk Newsletter
USA Today reported earlier this week that NOAA's Climate Prediction Center did not score too highly in its winter season outlook for Minnesota. In October the CPC forecasted a warmer than normal winter with equal chances for above or below normal precipitation. On the temperature feature, it was the complete opposite, delivering a 2007-2008 winter season that was colder than normal in Minnesota. On the precipitation side, it was generally drier than normal for the winter season. Overall across the USA, the newspaper weather writers graded the CPC with a B- for their winter season outlook

The Windy City From USA Today
Chicago is known as "the windy city", but it is not as windy as some MN cities. According to the National Climatic Data Center's list of annual average wind speeds, Rochester is the windiest in MN, with an annual average of 13.1 mph. According to the 1930-1996 Climatic data, the predominant wind direction is NW with a peak gust of 85 mph. Going down to Chicago, the average wind speed is only 10.3 mph.

Lufthansa Landing From Weather Underground
A recent YouTube video captured a Lufthansa A320 attempt a landing in a wind gust. With the wind blowing from right to left, the plane has an unusual approach angle to the runway. When the wheels touch down, the rudder is straightened, and then, a strong gust of wind lifts up the right wing, pushing the left wingtip of the aircraft into the runway. The initial report indicated a wind gust measuring 155 mph, but was later corrected to 56 mph, indicating confusion that the plane's landing speed was 155 mph. The world record for a thunderstorm microburst is 149.5 mph 01-Aug-1983 at Andrews Air Force Base near Washington D.C.

Weather Podcasts
One feature available on Minnesota Public Radio (MPR) are pocasts on various weather topics. The Jet Streaming episodes are approximately 25 minutes in length and can be downloaded in .mp3 format. Every week Jet Streaming brings an insider's look at the weather and climatology.

Equinox vs. Equilux From USA Today
Meteorologists and climatologists consider spring to be March through May. The equinox is often defined as when daylight and night hours are equal. The equinox is not really a day, but rather a moment in time when the sun's direct rays are striking the equator perpendicularly. This is different than equal day and night. The date of equal day and night hours is sometimes referred to as the "equilux." To find out when that occurred locally, use the U.S. Naval Observatory website. For data for Owatonna:
Monday - 17-Mar: Sunrise 7:21 a.m. Sunset 7:22 p.m.
Tuesday - 18-Mar: Sunrise 7:22 a.m. Sunset 7:22 p.m.

Another feature of the equinox is the sun rises due east and sets due west. During the remainder of spring and summer, the sun will rise and set north of due east and west, before returning to its due east and west position at the autumnal equinox. During the fall and winter, the sun rises and sets south of due east and west.

Animal Folklore Answers
1 - True, 2 - True, 3 - True, 4 - Possibly, 5 - True, 6 - False, 7 - True
8 - True, 9 - Possibly, 10 - True, 11 - True, 12 - True, 13 - True, 14 - False
Go to NASA for brief explanations of the answers.

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All Rights Reserved
Steele County SKYWARN
Owatonna, MN