April 21 Newsletter

The next SKYWARN meeting is 21-Apr @ 7:00 PM, the third Tuesday of the month.

Two individuals that took the SKYWARN training class in March also passed the exam for their Amateur Radio license. Congratulations to Paul KDKRX and Sue KDKSH. If you missed the 2010 Amateur Radio class, check the OSCAR web site for more information on other class opportunities.

Radar Learning Materials
Marv NFJP submitted a link to some good training material. The College of DuPage (IL) NEXLAB. Under the heading Preparation Materials: 2800 Students is a Word document illustrating how to use some of the features for GRLevel3. He also found a PowerPoint presentation on radar Analysis from Florida State University.

Vehicle Warning Lights
Some spotters may have auxiliary flashing lights on their vehicle. Minnesota Vehicle laws include required lighting on vehicles as well as restrictions. For example, law enforcement would severely frown on rotating red and blue lights on a private vehicle. MN Statute 169.59 describes the types and uses of warning lights on vehicles. There is a MN DOT list of approved warning lights used in work zones. If you have any lights, you might also want to think about some current research. It was mentioned at the March SKYWARN meeting that research is starting to explain why vehicles crash into police cars with flashing lights. Research is suggesting drivers that are tired are drawn to the flashing lights while alert drivers know to stay away.

Sun Spots From USA Today
We read a lot about recent increases in sunspot activity. The magnetic storms on the surface of the sun are one feature amateur radio operators use to help achieve long distance communication. Sunspots generally follow an 11-year cycle of maximum activity and minimum activity. This activity is now coming out of a period of minimum activity. Weather patterns across the Northern Hemisphere may be affected by this pattern of solar maximums and solar minimums. For example, variations in sunspots may be a cause for warmer winters.

Flood Measurement From Ohio State University
An OSU study found that satellites designed to measure sea level over the world's oceans can serve a valuable purpose over land. NASA's TOPEX/Poseidon satellite and the European Space Agency's ENVISAT satellite measure the height of land or water by bouncing radio signals off of surfaces and measuring how long the signals take to return. Rough surfaces scatter some of the signal in other directions, and cause errors in a satellite's on board tracking system. This often happens over land. Scientists use "re-tracking" software to fix the errors, and make the satellite's measurements more precise. The Ohio State project re-tracks the satellite data in a way that enables detailed measurements of water on land.

The study group processed TOPEX/Poseidon data from the 1997 Red River flood in the upper Midwest of the United States. They detected flooded regions within four river basins: the Red River Basin in North Dakota and Minnesota; the Missouri River Basin in North Dakota and South Dakota; and the Minnesota River Basin and the Mississippi River Basin, both in Minnesota and Iowa. The researchers also looked at data from the June 2008 Iowa City flood that killed three people and damaged 2 million acres of farmland. They found that they could track the ebb and flow of that flood over a scale of several hours. The satellites can't be used to forecast a flood because the data isn't processed very quickly and the spatial coverage of the satellite measurements is limited. After a flood, however, data can add to data collected on the ground.

Lightning Photography From Wired
A South Dakota researcher uses a high-speed video camera to capture lightning. Images at up to 54,000 per second loop though the memory. When a bolt of lightning is visually seen, the trigger is pressed and the camera captures the previous 2.5 seconds of images. You can see some of the results in six videos.

El Nio and Tornadoes From USA Today
El Nio is present across the equatorial Pacific Ocean and is expected to continue at least into the Northern Hemisphere spring 2010. This El Nio winter has been wetter-than-usual, suggesting an above-average number of tornadoes this year.

Climate Modeling From New Scientist
Climate models are typically run on robust computers with detailed mathematical models. Many climate processes such as cloud formation or the movement of air currents are too complex to simulate exactly. Models approximate these processes over a particular region of the planet, dividing it into grids typically around 100 kilometres across. While researchers are striving to make the models more realistic, they are limited by the processing power of the supercomputers that run them. Researchers suggest running simulations on cheap computer chips that produce results tainted with random noise could improve those models.

Hurricane Season Prediction From USA Today
The hurricane season for the Atlantic will begin on 01-Jun. One forecast is about 18 tropical storms with 7 of them making it to US shores. Generally, the forecasts are based on factors such as El Nio/La Nia as well as current and projected measurements of sea-surface temperatures, sea-level pressures, and vertical wind shear. Reasons for an active season are the rapidly weakening El Nio, warmer ocean temperatures, weakening trade winds and higher humidity levels. New research is suggesting that the activity in the Atlantic and Pacific regions have an inverse relationship. In other words, if tropical cyclone activity in the Atlantic basin increases, tropical cyclone activity in the eastern Pacific basin decreases, and vice versa.

WX Satellites From USA Today
The replacement program for weather satellites is five years behind schedule. Four satellites used for weather forecasting are projected to reach end of life by 2020. Approval for the replacements has been hung up due to cost estimates and technical problems.

Term For The Month From Minnesota WeatherTalk
This is an old British term from the 19th Century and refers to a mender of umbrellas. The canopy or umbrella over a cab or taxi pulled by a horse was called a mush or mushroom. Thus a mushroom-faker or mushtopper-faker was a person who mended such canopies. In modern times we do not mend umbrellas, but buy new ones when the old ones break. I suppose there may be some antique or extraordinary hand-crafted umbrellas that may be mended from time to time.

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Steele County SKYWARN
Owatonna, MN