It's a question on many minds this time of year... what is the winter going to be like?
Our Sky Tracker meteorologists have been asked this many times already this year.
Over the past few winters, Mother Nature has "toyed" with us... providing a winter of record snowfall just a couple of years ago, to one of the brownest and warmest years even long time locals have ever experienced. Chief meteorologist Kerrin Jeromin looked in to winters past to develop a seasonal outlook for this coming 2012-2013 winter.
Think back to March 6-7th of 2011, the last wallop of snow for our region after a winter of record snowfall. That winter, nearly 130" of snow fell in the Burlington area.
Now, think about last winter. A winter for the record books for least snowfall with only 37" of snow in Burlington...about half of average.
"I think if we see another winter like that, as warm, I think a lot of people will be scratching their heads wondering if there's something more than we just aren't aware of yet", explains Mike Halpert from NOAA's Climate Prediction Center.
After analyzing winters past, looking at what weather patterns existed each season and what kind of winter we had, and with the use of weather models, Kerrin expects a slightly warmer and slightly lower than average snowfall this winter compared to any average winter season.
"Every year has its variability and really what it all boils down to is the location of the jet stream", explains Paul Sisson from the National Weather Service in Burlington.
The jet stream is a fast flowing current of air in the upper atmosphere. Located about 4 to 8 miles above the Earth's surface, the jet stream is the steering mechanism for storm systems. It is also the cutoff of cold air to the north, and warm air to the south.
"Obviously for snow we want cold air", Sisson says.
In the Northeast, one of the big players in what kind of winter we see, lies in the Atlantic ocean. The changing location of high and low pressure systems determine just how much cold air can flow southward away from the Polar regions. The problem with this is that we can only forecast that pattern about a week or two out…not months in advance.
"Until we're able to come up with a way to reliably forecast that, winter will probably continue to be a challenging forecast [in places like Vermont]", explains Halpert.
There are three other signs used to forecast for winters across the country. The first, and most reliable, is the ENSO cycle. This is more commonly known as El Nino or La Nina and is the fluctuation of water temperature in Pacific ocean.
"In many winters, we either have an El Nino or La Nina and that helps provide some type of a consistent forecast signal that tilts us in one direction or another. And this year, we don't even have that to latch on to", says Halpert.
Second, trends in regional climate are also considered in long term forecasting.
"[In Burlington], we've seen a slight increase over time. But, you can still see big peaks and big valleys from year to year in our snowfall amounts", explains Sisson.
The third, and newest clue, and likely perhaps the future of forecasting, is the use of computer models.
"That's on a lot of people's minds. Not only what the winter will look like, but the next 10, 20, or 30 years going to look like", explains Sisson.
Based on current weather model data, winter should get off to a warmer than average start, but return to normal by early 2013
One final thing to keep in mind... the terrain plays a large role in snowfall totals each season.
According to local climate data, valley areas average anywhere from about 50-80 inches of natural snowfall each season. Whereas many of the nearby ski areas average anywhere from 200-300 inches of snowfall...some even more.
Consider this, even in last winter's sub par year, Jay Peak ski resort had about 250 inches of natural snowfall...quite a bit more than that measly 37 inches in Burlington.
So, with Kerrin's current forecast of below average snowfall and slightly warmer than average temperatures, it's important to remember, it's all relative to each little microclimate across our region.
