60
      Monday
      85 / 61
      Tuesday
      87 / 63
      Wednesday
      84 / 63

      10-29-12-That's What Karl Says

      Does a wet October lead to a snow winter here in Upper Michigan?

      October 2012 will end on the wet side of average. Through today, the NWS has collected 4.75 inches of rain and some melted snow for the month. The average is 3.66 inches. I looked back at the past 60+ years (1949-2012) of data. Up until 1979, the data was taken in the City of Marquette, since then official readings are taken at the National Weather Service (NWS) near Negaunee. I used the criteria of at least 4.50 inches of precipitation during the month. During this time the wettest October was in 1979 when NWS collected 7.59 inches of rain and melted snow at the Negaunee Township site. When the service was in the city, the highest total occurred in 1959 with 7.13 inches.

      There were 17 Octobers (not including October 2012) which fit the above criteria during this time period. Evidence shows that the majority of wet Octobers were also cold. Only six in this sample were average or above.

      The question, ??What sort of winter follows a wet October??? The quick answer is ??A potpourri of winter weather conditions.?? Eight of the following winters were snowy, so in this sample, a wet pattern doesn??t necessarily continue into the winter. As for temperature, there is a moderate tendency for a cold following winter. Ten out of the sample of 17 turned out to be cold. Out of those ten, seven hit the jackpot and were cold and snowy.

      Of the mild winters, only two were snowy. One, 1959-60 was exceptionally snowy. Marquette nearly had its snowiest winter with just over 188 inches. The winter of 2005-06 was judged snowy because of a quick start and a snowy February. That year had a ??blowtorch?? January when the month averaged over 11 degrees above normal. A mild winter followed the wettest October in 1979, so the wettest Octobers don??t increase the odds for a following severe winter. Four of the five mild following winters were El Nino winters. For example, October of 1986 was wet and cold; the next winter was exceptionally mild as a rather strong El Nino developed. Then again more recently, the winter of 2002-03 was a moderate El Nino. It was cold through November into early December. It then warmed to well above average through mid-January. Afterwards there was severe cold, but little snow.

      The bottom line is that you can??t reliably base a winter forecast on what happens during the preceding October.