Hello there! So your winter weather curiosity has led you here. Come on in, the water’s warm. For now.
This article is designed to provide you with the best and latest guidance we have available suggesting how WNY’s winter season might play out. We’ve dedicated many hours of study in trends, patterns & historical data to amass a forecast we hope will give you with the kind of insight you’re looking for. But before we peel the tarp back on this forecast, we have a few things we want to make clear up front.
We at News 8 regularly issue an 8 day forecast. In fact, it’s one of the staples you see on TV every day. There’s a reason we only go out to 8 days. Beyond roughly a week, the scientific accuracy of a forecast drops precipitously. That’s not a knock on the fine meteorologists we have in this building, it’s simply the best the current state of meteorology allows.
We also happen to live in a part of the world with varied microclimates. These are small, unique regions that tend to produce unique, highly localized weather. It’s nearly impossible to put a single number (temperature, snow, etc.) on the entirety of WNY. With these realities, it seems like a tall order to attempt to quantify an entire winter season that spans several months throughout many microclimates. Everything you read from here on out should be digested with this reality.
Seasonal forecasts tend to be poor in terms of accuracy. If I’m being completely honest, I question whether it is beneficial to even venture down the road of a seasonal forecast, particularly speaking in anything greater than generalities. But you’re going to have no trouble finding winter outlooks online, so I’d rather you get the information from us put in the proper context. Now that you’re prepped and buckled in, let’s take the ride.
The first stop on our winter outlook venture takes us to the world of La Nina. You’ve already met. Last winter featured a La Nina. You’re also likely familiar with El Nino, its cousin. La Nina features a cooling of ocean waters in the Equatorial Pacific. While this might not seem overly relevant to WNY, the implications of such a phenomenon are wide reaching.
For our area in particular, La Nina winters tend to feature warmer than normal temperatures and higher than normal precipitation. It results in a relatively active jet stream that carves a path through the Great Lakes and New England. NOAA’s winter weather outlook leans very heavily on this reality, and it is no surprise the general flavor of our forecast leans warm and wet.
La Nina aside, this whole warm and wet thing should be familiar to you. Much of our summer and fall fell into that category, so it might make some sense that this trend will continue (By the way, James showed that there really isn’t much connection between a warm summer & wild winter):
The thing is, “warm & wet” doesn’t preclude intrusions of cold air nor offer any real insight into how much of that “wet” falls in the form of rain vs. snow. Complicating matters further, we’ve had many winters through decades past featuring similar calibers of La Nina. And guess what? There is little information to be gained in the snow department.
Since the 50s, we’ve gone through 16 weak/moderate winter La Ninas. We’ve had duds and we’ve had monsters in terms of seasonal snowfall. Rochester averages about 100″ during any given winter. The average during those 16 La Ninas? 100″…not particularly helpful. Our quest continues.
There are several large scale oscillations that often prove fruitful in forecasting winter weather locally. The North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) are teleconnections we often reference during the winter months. Tough to utilize them on the scale of months, but certainly days & even weeks. This starts taking us down the detour of the infamous polar vortex, a ribbon of strong upper winds that serve as sort of a barrier to contain the coldest of cold air. When the polar vortex is strong, the cold air remains locked well to our north. When the jet weakens, pockets of cold are able to ooze southward into the United States, often presenting the setup for our coldest stretches we achieve on any given winter.
Filed under the “strange but true” category, snow cover in Siberia around October can offer insight into how the polar vortex might behave in winter. Lots of snow cover suggests the polar vortex is likely to weaken, amplify and send could air southward in our direction. Snow cover this October was slightly more than normal, but not significantly. There is perhaps a slight bit of information to be gained from this, perhaps suggesting arctic outbreaks could be slightly more frequent than experienced last winter (when we saw very few).
At this point in our journey, we’ve established only bread crumbs of help from large scale patterns. I think this winter’s secrets might be resting right under our noses. Lake Ontario is running warm right now. Historically warm, in fact. First blush, it’d be easy to rush to the judgement that a warm lake probably doesn’t mean lots of snow. But it might.
Those extra degrees are primed to serve as added instability if/when intrusions of cold air finally materialize. A warmer than normal lake should, in theory, provide the dormant fuel for significant lake effect snowfall. Just because La Nina winters lean warm overall doesn’t mean there won’t be periods of cold. There will be. And when they come, our warm lake will be first at the door to greet it with all that extra energy. We think Lake Ontario will play a more important role than past seasons.
Rochester (and all of WNY’s) seasonal snowfall is made up in two parts. Lake effect and synoptic, or system snow. The latter comes from areas of low pressure tracking in our vicinity and dumping widespread snow on everyone. Our lake effect snow is highly localized and highly variable. An accurate outlook must attempt to grasp how robust each of these elements might be. La Nina suggests an active storm track, or a greater quantity of waves of low pressure affecting the area.
Much like last winter, I question how many of these will ultimately be able to produce snow vs exhausting their moisture in the form of rain. Many of these systems will be split, featuring rain and warmer air on the leading side followed by snow and colder air on the backside. A few will likely feature all snow and should serve as our bigger hits of the winter. Overall, we don’t feel like synoptic, “system” snow will be terribly different than normal, or average. In fact, a similar La Nina last winter produced below average synoptic snowfall.
The lake effect snow remains the wildcard. While La Nina will likely limit the frequency and caliber of cold air outbreaks, we’re confident there will be more than enough to keep lake effect snow at the forefront this winter. But remember, this snow will be very localized. Those of you who live in parts of WNY that generally don’t worry much about lake effect snow won’t cash in on this part, relying almost exclusively on the synoptic snow that might not be particularly robust again this winter.
However, those who live in the typical hot spots (Wyoming county, lakeside & east into Wayne county) stand to get hammered harder than usual. In these areas, a lukewarm synoptic snow outlook is overshadowed by the prospect for significant lake effect snow.
Rochester has failed to see 100″ snow in the last 3 winters. That hasn’t happened since the 1980s. We’re not convinced we’re going to get to 100″ this winter, but we feel like we’re going to be close. That would make this winter’s snowfall greater than what we dealt with last winter and more in line with the 2018-2019 and 2019-2020 seasons that features a little over 90″. Keep in mind, such a forecast is only one good snowstorm or heavy lake effect event in Rochester away from getting to the triple digits, a prospect we acknowledge is feasible should lake effect favor the Rochester Airport.
Remember, it’s not just lake effect happening for Rochester’s number, it’s the very specific wind direction that dictates where the bands settle. We get a few events with a favorable ROC flow, and boom. As of this moment, we’re in the midst of another slow start to the young season, much like last year.
In conclusion, another warm and wet winter looks like a good bet for all of us. For Rochester, snowfall amounts of slightly below normal to normal is the call. The Finger Lakes should fall into this category as well. Areas closer to the lake and east into the higher terrain where lake effect is more prominent may very well see a normal to slightly above normal snowfall season. Should arctic outbreaks prove to be more frequent than currently expected this winter, these areas stand a reasonable chance at seeing well above normal totals.
Plows should find the most work chasing these lake effect bands this winter, but you’ll put in some hours with generalized snows at times. The active storm track could also allow a few mixed precipitation events, perhaps introducing some freezing rain into the equation. The overall greater quantity of precipitation will keep water levels running healthy to high through the winter with implications on the new spring and summer seasons next year. Should this overall wet pattern continue into 2022, flooding may be a topic of continued conversation once the winter is done.
-Chief Meteorologist Eric Snitil