The first weekday of each month, I share my monthly forecast with our necn morning viewers. The purpose is to give a general overview of the month ahead, and with winter weather quite limited thus far in the winter of 2015/16, the big question many New Englanders have is, 'Will February deliver what's been missing?' Overall, the answer is probably not, though some shots of cold and snow remain possible.
Sticking to the El Nino winter script, this winter has seen remarkably warmer-than-normal temperatures for much of the United States, and the Northeast through New England has been no exception. Similarly, the El Nino Pacific storm track has been active, bringing Pacific storms sailing into the U.S. West Coast, but that parade of storms each bring relatively mild Pacific air with them, further reinforcing the warm pattern for the Continental United States.
In the last two weeks, an interesting phenomenon has appeared at the North Pole - warming air aloft. Most of our weather is made in the lower tens of thousands of feet of the atmosphere, called the "troposphere", but that doesn't mean what happens higher up in the sky has no influence on our weather. In fact, it's been noted that in winters when the "stratosphere" - the next layer of atmosphere up - warms quickly near and over the North Pole, cold air can be displaced southward at the surface. This "stratospheric warming" was a key component to initiating the now infamous "Polar Vortex" shot of deep cold into the United States two winters ago, and is happening again at the North Pole right now. There's a huge difference this time around, however - the strong El Nino winter has spread warmth across the North American continent, and this will severely hamper any attempts of deep cold to make a lasting stand. What we're likely to be left with is a shot of cold with the greatest chance of occurring mid-month and again at the third week of the month, which will push temperatures below normal for most of the country and even for a time in the Northeast, but would not last long enough and with enough intensity to offset an otherwise continued pattern of warmth. To the north of New England, some of Eastern and North-Central Canada may be able to record a near-normal February for temperature, it just doesn't seem likely at this point that such a strong impact would spread farther south to offset the month.
Precipitation looks to be above-normal in February, owing to a continued contribution of the subtropical jet stream into energetic disturbances traversing the country. This subtropical jet stream is different from the normal, polar jet stream we focus on - the polar jet typically separates cold air to the north from warm to the south, and carries energetic disturbances that often means these winds steer storms across the country. The subtropical jet stream doesn't have the same type of influence over temperature, as it's separated from the colder air of Canada, but subtropical winds do contribute ample amounts of tropical moisture from the Pacific and the Gulf of Mexico, and when interacting with the energetic disturbances and cold air in the polar jet stream, can create large, moisture-loaded storms. It's for this reason that the East Coast and Gulf Coast both seem to be in line for "juicy" storm systems in February...but with so much warmth, this may mean more mixed precipitation events. Of course, with the aforementioned propensity for cold air around mid-month and the third week, this also would raise the chances in that period of snow rather than rain, but as usual, that will hinge upon coincident timing of both the cold and moisture.
In summary, February should be a month that keeps meteorologists and Northeast residents, alike, on our toes and ready for some wintry blasts, but not a month to offset the so-far lackluster winter before transitioning inevitably to spring next month.
Local
Matt
