Our seasonal forecasts are really based on data we find in our climatological database for Syracuse, not the computer models we use for our shorter term forecasts.  What we do is look for unusual weather patterns from our current season then try to match them with past years that had a similar patters (colder, warmer, drier or wetter than normal stretches).  This winter, the weather pattern that may hold a key to our early Spring weather is a wet February.  Our liquid equivalent (rain and melted snow) for February 2008 is now about 4” and that already puts us into the top ten wettest Februarys on record. 

When looking at Springs that followed wet Februarys here is what we found.  8 out of the 10 Februarys we looked at ended up with below normal temperatures.  That’s a pretty strong statement.  The average snowfall in these colder than normal Marches was close to 30” which about a foot more than an average March.  Based on past numbers the cold weather could linger into April. After those wet Februarys 7 out of the 10 following Aprils were also below normal in temperature.

The other signal we used to make our Spring Forecast was the ongoing La Nina.  La Nina is colder than normal surface sea temperatures over the Equatorial Pacific, in particular the eastern Pacific Ocean.  The La Nina has been with us all winter and will likely linger through the Spring. 9 out of the 12 La Ninas years ended up with colder than normal Marches and the snowfall was similar too (27” vs 30”). The signal for April wasn’t as strong for La Ninas as it was with wet Februarys, with only 6 out of 12 years pointing toward below normal temperatures with a tendency for a bit more than the 4” average of snowfall.

In both cases, the La Nina and wet Februarys didn’t give us many clues for the month of May.  They basically split almost down the middle between warmer and colder than normal Mays.

There were other things we looked at like snowy Decembers and 60 degree warmth in January and none of those helped like wet Februarys. We’ll see how things pan out over the next few months but to be safe I’ll probably keep my snow tires on just a bit longer this year..