Because it has such a big influence on our cold season weather here in Wisconsin, I follow the twists and turns of El Nino and La Nina out in the Pacific ocean. Just last week, the CPC released its monthly diagnostic discussion of the tropical Pacific ocean pattern.
At one point around late Summer and early Fall it had looked like a weak to moderate El Nino could develop for the Winter. Which could have meant well above normal temps and less snowfall for our area. Now it looks like the El Nino will not officially form. The latest analysis indicates a slightly positive (warmer than normal) surface water temperature in the central Pacific and this is expected to slowly return to neutral over the next couple of months. For reference, the temperature has to be at least a half a degree above normal for a few months before an El Nino is officially declared.
So what does this mean for the rest of our Winter? It means there is no major climate signal to hang our hat upon – to give us a good clue as to whether the weather will be warmer or colder than normal – whether precipitation will be above or below normal.
Thus far, the Winter (first two weeks of December) in Wausau has been well above normal – even ahead of last year when the average temp for December was a whopping 6 degrees above normal! It looks like this milder trend will continue through the middle of next week before we start to see a chance at more colder weather. So December will probably go down as the 10th out of 12 months with above normal temps in 2012. Will it continue? Without El Nino around there is at least a better chance of more normal Winter conditions in January and February. The key thing for enjoying Winter is snow and even if it is mild we could still end up with a good amount of snow. All it takes is a couple of big storms (6 or more inches of snow) and we will be able to open up the snowmobile trails.
Another good thing about heavier snow (even in the absence of cold) is that drought conditions will have a chance to improve. The latest US Drought Monitor indicates most areas of the country, including Wisconsin have not shown any improvement in the last couple of weeks. In fact, drought conditions as a whole have increased over the last month, mainly due to expanding dry conditions in the southeast (although they did have some heavy rain just over the last couple of days). So keep your fingers crossed for more snow, or even rain, even though that is less fun this time of year.
Have a swell Thursday! Meteorologist Justin Loew.
This post was written by jloew on December 13, 2012