Published: 2007-04-09 07:49:56
Updated: 2007-04-09 07:49:56
Posted April 9, 2007 7:49 a.m. EDT
MIKE MOSS SAYS: Blanche, The usual meteorological factor involved in springtime cold outbreaks is the development of a deep and slow moving upper level trough of low pressure over the eastern half of the United States and Canada, which is capable of funneling unseasonably cold air southward into central and eastern parts of the country. Although we may look back and associate these kinds of outbreaks with a notable marker like the Easter holiday, the timing and intensity of these outbreaks can be quite variable from year to year, and rather than a special phenomenon that is associated with a particular weekend in March or April (since the timing of Easter varies by about one to three weeks from year to year) it is probably more reasonable to think of these as simply among the last cold outbreaks of the winter that that has recently ended and is in the process of giving way to spring. Strong cold outbreaks are rather frequent and fairly regular through the heart of the winter, then become more variable in intensity and less and less frequent, but not impossible, as we head through March, April and early May. They probably stand out more in memory due to the fact that we have usually experienced some very mild or warm periods of weather by the time these late season chills occur.