Why has weather been so extreme?

March 3, 2009 4:29:02 PM PST
It's been one wacky winter but has the chill in the air been colder than usual?

From the very beginning, winter put us on a rollercoaster ride-after a warm December, January turned cold, then a February warm-up has many wondering is this extreme.

When you look at February as a whole there were dramatic extremes but when you break it down it's not out of the ordinary.

17 days came in above normal temperatures and 11 days were below normal. The most extreme change fell in the first week. On the 5th it was 22-degrees, then 69-degrees six days later. True this is a huge change but it all comes down to an average.

While one day we are wearing all the layers we can and soon after taking them off, one may not realize. The average between the 5th and the 11th was 45-degrees, just slightly above normal. This happens every winter and its how we obtain our monthly average in the meteorology world.

What ultimately drives the ups and downs is the jet-stream. S-T-6 is one tool to follow the storm patterns across the country.

Last month the northern jet-stream mainly stayed north locking and building the cold air in Canada, while the southern stream brought record rain and snow to the west. This area sat in the middle but the last couple days the cold air got so intense it broke south and phased with the southern jet, which holds the moisture. It brought us lots of snow and extreme cold but what seems extreme now is only part of an average cycle.

Another extreme example: Tuesday we did not break out of the 20's; by the weekend we will be in the 60's. It sounds and is extreme, but when you average the week, it will come out to 44-degrees which is normal for this time of year.

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