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Weather and Meteorology Notes

Fall 2010

How is fall 2010 shaping up compared to fall 2009?

Interesting tidbits to entice and amaze your students!

As the 2010/2011 school year gets underway for teachers and children in Ontario, you might be wondering what’s in store for fall weather and other autumn events in 2010.

But first, what was Ontario’s weather like in 2009? According to Environment Canada’s Top Ten Weather Stories for 2009 (http://www.ec.gc.ca/meteo-weather/default.asp?lang=En&n=645A8F9C-1), the fall of 2009 for central and southern Ontario was one of the driest on record! In September, Ontario was hit with a heat wave and no rain fell in Toronto for 19 days. A dry spell like this hadn’t happened since 1938. September usually has the most rainy days of any month, but this dry spell has been credited as saving many crop harvests after the second wettest Ontario summer on record. While October proved to be cooler and slightly drier than average for most of the month, this did not stop a stunning display of fall colours. Across southern Ontario in November, weather stations recorded some of the warmest temperatures and record-breaking hours of sunshine. Unlike the grey and wet conditions we usually experience in November, 2009 was recorded as the fourth sunniest November. As a result, it was also the first snow-free November recorded since 1937 at Pearson International Airport. In contrast, December proved to be a relatively “typical” month in terms of average temperature and precipitation numbers. The month started off with mild temperatures, then the first snow fell on December 10, dumping up to 125 cm of snow in the Muskoka and Haliburton area. Officials in Huntsville and Bracebridge even declared a snow emergency for the region, the first in 40 years for that area.

Now, what about fall 2010? The Farmer’s Almanac (http://www.farmersalmanac.com/long-range-weather-forecast/ontario/) predicts that September and October will be cooler than usual this year, with squally weather moving into Ontario towards the end of September. Rain and heavy precipitation is also anticipated for the latter-half of October. On the other hand, the fall colours of 2010 are anticipated to be spectacular! Climatologists from Environment Canada say that this fall season will be one of the best in recent history for vibrant fall colours. This is because it has been warmer than usual through the summer, yet Ontario has also seen adequate precipitation. In central Ontario, fall colours are anticipated to be at their peak by the end of September, and by mid-October for southern Ontario. Fall is also a great time to take part in harvest events such as apple-picking, or to visit on of Ontario’s many local fall fairs!  The autumn equinox, the time when day equals night, will occur on Thursday September 22 at 11:09 pm EDT. The winter solstice, the time when we experience the fewest hours of sunlight in day, will occur on Tuesday December 21 at 6:38 EDT.

Noteworthy celestial and meteorological events in fall 2010

  • September 21 - Jupiter at Opposition. The Solar System's largest planet will be at its closest approach to Earth. This is the best time to view and photograph Jupiter and its moons. The giant planet will be a big and bright as it gets in the night sky. A medium-sized telescope should be able to show you some of the details in Jupiter's cloud bands.  
  • September 22 - Uranus at Opposition. The blue-green planet will be at its closest approach to Earth. This is the best time to view Uranus, although it will only appear as a tiny blue-green dot in all but the most powerful telescopes.  
  • October 20 - Comet Hartley 2 will make its closest approach to Earth, coming within 11.2 million miles. For a few days around October 20, the comet should be bright enough to view with the naked eye in the early morning sky. You will, however, need to be far away from the glow of city lights. Look to the east just before sunrise. In early November, NASA's Deep Impact spacecraft will observe comet Hartley 2 from a distance of about 600 miles.  
  • October 21, 22 - Orionids Meteor Shower. The Orionids is an average shower producing about 20 meteors per hour at their peak. This shower usually peaks on the 21st, but it is highly irregular. A good show could be experienced on any morning from October 20 - 24, and some meteors may be seen any time from October 17 - 25. Best viewing will be to the east after midnight. 
  • November 17, 18 - Leonids Meteor Shower. The Leonids is one of the better meteor showers to observe, producing an average of 40 meteors per hour at their peak. The shower itself has a cyclic peak year every 33 years where hundreds of meteors can be seen each hour. The last of these occurred in 2001. The shower usually peaks on November 17 & 18, but you may see some meteors from November 13 - 20. Look for the shower radiating from the constellation Leo after midnight. 
  • December 13, 14 - Geminids Meteor Shower. Considered by many to be the best meteor shower in the heavens, the Geminids are known for producing up to 60 multicolored meteors per hour at their peak. The peak of the shower this year should occur on the night of December 13 and morning of the 14th, although some meteors should be visible from December 6 - 19. Some estimates say there could be as many as 120 meteors an hour visible from dark-sky locations. The radiant point for this shower will be in the constellation Gemini. The Moon will set early in the evening setting the sky up for a spectacular show. Best viewing is usually to the east after midnight 
  • December 21 - Total Lunar Eclipse. The eclipse will be visible throughout most of eastern Asia, Australia, the Pacific Ocean, the Americas, and Europe. The eclipse will be visible after midnight in North and South America. Since the Moon will be almost directly overhead from these locations, this should be an excellent chance to view a rare total lunar eclipse.

Source: NASA Eclipse Information