Every year, the WROC weather team huddles together and pours over available data as we try to come up with a Winter outlook. Truth be told, long range seasonal outlooks tend to have a poor degree of accuracy. Think of it like this, it’s difficult enough to know what the weather is going to be like a week from now, let alone 5 months from now. So why bother? Every Winter, we’re able to look back and see if Mother Nature had left us any “clues” as to how things were going to play out. More times than not, we’re able to go back and find a few of these bread crumbs and hope to use them in the future.
There are some bread crumbs for this Winter. The biggest one is La Nina. It’s a cooling of Pacific equatorial waters (the opposite of the more well-known El Nino). While that water is a long way from WNY, it has an effect on the overall pattern that eventually affects us. La Nina Winters tend to feature a rather active storm track across WNY. This means we see a good amount of passing storm systems, of which will be producing precipitation. That much we know. What we don’t know is what the exact track of these storms will be each time they zip on by. Westerly tracks tend to produce more rain. Tracks overhead are a mixed bag and tracks to the southeast will be bigger snow makers. No way of telling what each storm is going to do, but the fact we’ll have more of them around is important.
Also important is snow cover in Siberia, of all places. Less snow cover has an effect on something called the Arctic Oscillation, contributing to how the Polar Vortex is going to behave this Winter. The theory is this: Lower Siberian snow cover in the Fall tends to suppress how amplified the Polar Vortex is going to be. The more amplified the Polar Vortex, the more bouts of bitterly cold air we get. So if the Polar Vortex isn’t going to be as amplified, in theory, we see less intrusions of Arctic air. Got it? Good.
So what does that all mean? Great question. Specifics are impossible to know, but here’s what we’re relatively confident in. This Winter is going to lean warmer. That doesn’t mean we won’t have cold snaps. We will. But the overall flavor likely leans above average in the temperature department. We should also be wetter. That more active storm track means more overall precipitation. Does that mean snowier? Not necessarily. Some of that precipitation will be exhausted in the form of rain, and it’s unlikely all of it falls as primarily snow given the warmer flavor of temperatures. Rochester average around 100″ of snow each Winter, and that seems like a fair starting point this season. I suspect we’ll have a higher propensity to see mixed bag events, which could spell a few icy systems where freezing rain becomes a problem. Warmer weather means warmer lake, so any cold snaps could produce more potent lake-effect snow events. More potent perhaps, but shorter-lived.
Worth noting too, there is some evidence to suggest the more “Wintry” stuff will favor the second half of the Winter vs. the first. That could mean months like February and March have more bite than usual. Time will tell. Regardless, this overall pattern very much suggests this Winter won’t be quiet. Whether it be rain, snow, or some mix of everything, that active storm track will be keeping us on our toes this season.