Dear Tom,
There have recently been several very slow moving storms where the precipitation moves from east to west, rather than the usual west to east. Is this phenomenon related to climate change/global warming?
—Mark Zablocki, Bloomington, Ill.
Dear Mark,
No, it is not related to climate change. Rather, it has to do with your position with respect to the low pressure systems associated with the precipitation. In the situations which you describe, you are to the north of the lows and your prevailing wind circulation is from an easterly direction. Winds circulate in approximately a counterclockwise manner around low pressure systems. When the center of low pressure is to your south and you are under the influence of the low, the winds at your location will be from an easterly direction.