March 21 Newsletter

The next SKYWARN meeting is 16-Mar @ 7:00 PM, the third Tuesday of the month.

Spotter Class From Dave KCUVY
The 2010 Spotter Class is scheduled for 09-Mar on the 3rd floor of the Owatonna Fire Station. Beginning at 7:00 PM, anyone interested in severe weather is invited.

The MN SKYWARN Workshop is scheduled for 10-Apr at the University of St. Thomas in St. Paul. Pre-registration is strongly encouraged. The workshop cost is $15. Registration "at the door" will be very limited by available space with a workshop fee of $30. Pre-registration also allows participants to order a tee shirt and lunch.

Freezing Rain From Minnesota WeatherTalk
The Twin Cities and southern Minnesota communities historically record freezing rain or freezing drizzle about one day every other year in the months of January and February. Over the last two decades, however, the number of days has increased. The average frequency of has been 4 days each year since 2003, ranging from none to 7 year-to-year. This recent history agrees with climatological evidence that winters are getting warmer, dew points are getting higher. The result we are experiencing is a change in the types of winter precipitation.

NASA Global Hawk From Wired
NASA now has its own unmanned aircraft for data gathering. The aircraft can stay aloft for 31 hours with sensors measuring temperature, wind speed, and pressure. The 1,000 pound payload includes:

  • A laser-based system that creates detailed images of clouds and mist.
  • A 1.3- micron infrared beam bounced between two mirrors to measure water vapor in the atmosphere.
  • Chromatograph and spectrographs to analyze air samples for harmful gases.
  • A Nikon 8800 digicam snaps images every 20 seconds to track cloud patterns.

Thunder Snow From New Scientist
We certainly have had our share of heavy snow this year. The combination of snow, lightning and muted thunder occurs occasionally in storms across the temperate regions of North America, often near lakes or cyclones. Eyewitness accounts of these rare events, known as "thundersnows", date back thousands of years to ancient China, and suggest that lightning tends to strike in parts of the storm where the most snow is falling. Researchers studied 1000 lightning strikes in 24 thundersnows, knowing that bigger snowstorms tend to produce more lightning.They found that lightning tended to strike about 15 kilometres downwind of the heaviest bands of snow, so the heavy snow did not arrive until later. The finding may give meteorologists a way to predict snowstorm behaviour in near real time. Unlike rain, snow doesn't show up well on current radar systems.

World Record Wind Speed From USA Today
The record breaking wind occurred back in 1996, but was recently confirmed by the World Meteorological Organization. The wind was clocked at 253 mph during Cyclone Olivia on Barrow Island in Australia. The previous record of 231 mph occurred in 1931 atop Mount Washington in New Hampshire. Although not considered official, a Doppler radar in Moore Oklahoma reported a wind gust of 318 mph in 1999.

Lightning Safety It will soon be thunderboomer season across North America. NOAA has published a lightning-safety page that might be worth forwarding to family and friends. Mark you calendar for Lightning Safety Week: June 20-26, 2010

Climate Changes From USA Today
Global-average temperature records are vital to help understand how our climate is changing. The historical records are used to develop models to estimate future trends. Researchers have different techniques for calculating the global-average temperature. The different methods may produce variances over the short term, but generally agree over the long term. The Meteorological Office in the UK developed a graph comparing the three main calculations. Although independently derived from measurements, they depict very similar temperature trends for the Earth climate system.

When Auroras Collide From NASA
A network of cameras deployed around the Arctic in support of NASA's THEMIS mission has made a startling discovery about the Northern Lights. Sometimes, vast curtains of aurora borealis collide, producing spectacular outbursts of light. The collisions occur on such a vast scale, isolated observers on Earth with limited fields of view had never noticed them before. Twenty cameras were deployed across the Alaskan and Canadian Arctic to photograph auroras from below. Five spacecraft collected data on charged particles and electromagnetic fields from above. Amore complete story along with video links is available at the SCIENCE@NASA web page.

Term For the Month From Minnesota WeatherTalk
Swody1 and Swody2 (swoe-dee)
These are terms used by the meteorologists at NOAA's Storm Prediction Center in Norman, OK. They stand for the Convective Weather Outlooks for Day One and Day Two. They assess the threat of severe weather and whether or not to issue a watch.

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Steele County SKYWARN
Owatonna, MN