

Ask Tom Why

September 18, 2005|By Tom Skilling

Dear Tom,

Since we have had such a hot summer, what's our winter going to be like?


Dear Bob,

Temperature anomalies (such as hot summers) do not seem to be reliable predictors for precipitation. Consequently, they do not answer questions like, "Does a hot summer mean less snow in the winter?" That said, hot summers do give reliable clues about temperatures in the following December-January periods. In fact, hot summers tend to be followed by winters somewhat milder than normal. An in-house study of 77 years of Midway Airport temperature data (1928-2004) reveals that 12 (or 60 percent) of the December-January periods following the 20 hottest summers in that period were milder than normal. The number of 0(degrees) days in those 20 winters also averaged 40 percent fewer than might be expected (five days versus the normal of eight).



