Tomorrow is the first day of Winter 2021. While the high temps will only be in the 40s today, we are still likely not going to have any snow in the forecast for the next 7-10 days. We’ll actually be a bit mild on Christmas Day with high temps aiming for the low 60s.
What about the rest of the Winter? Let’s talk about it. A little while back I talked about La Nina and how it affects Winter forecasts overall.
On average a La Nina Winter will produce drier/milder weather across the Deep South and the Southeast.
While the first calendar day of Winter is tomorrow. There is something called Meteorological Winter. Meteorological Winter basically goes from December 1st through March 1st. This is just a way to simplify Winter forecasting and climatology. However, the overall pattern can change several times during those 3 months. So it is pretty complicated to even give a seasonal forecast. If you have a warm December and February but a bitterly cold January, then is it a bad Winter? If you have one huge snowstorm during that time, but no snow for the rest of the season, then is that a bad Winter? Winters in our region are almost always complex.
We have had some colder “La Nina” Winters when we have had some big snows.
However, it’s not a guarantee. There have been several “La Nina” years when we have had little or no snow.
The NAO is a pressure pattern over the northern Atlantic. When it is in the negative phase it produces a blocking pattern, and that creates colder weather along the East Coast during the colder months. We tend to be warmer during the positive phase. The Climate Prediction Center (NOAA) has us going positive in the short term, but going more negative by the new year.
The North Atlantic Oscillation and the Arctic Oscillation are two shorter-term patterns that are always a factor in possible snow in the eastern U.S. Since these patterns are much shorter-term you can’t really predict them for a whole season. Yet I do think the current pattern will change in about 2-3 weeks, and at least some colder weather will arrive for a while.
The forecast depends on many other factors. Some that are not in favor of snow this year are:
- Below average snowpack over Siberia
- Not much snow over the bulk of the U.S.
- Drought over a large portion of the country
- A warmer pattern overall during the late Fall (persistence)
We also just had extreme heat in the central U.S. and we had near record temperatures locally until yesterday. Snow acts like a battery for storing cold air. It allows cold air to sit and pool over a region. It is tough to do that without it.
Keeping all that in mind…. there are some factors that do favor some snow:
- There have been several cold punches that have lasted for about a week over the last couple of months.
- Temperatures have been well below average over Alaska and Europe. This has affected the price of energy there.
- It can’t stay warm forever. I think we are due for a pattern change within the next 2-4 weeks.
Have said all of that…. I think we are in a Winter that will favor less snow. It’s rare to have no snow, but it is possible. If we do get one or two of these colder streaks, and we can get some moisture in the region, then there is a low chance of a moderate to heavy snow. However, that chance seems low at this time. I’m not going to give amounts. Due to our proximity to the bay/ocean we can sometimes have huge gradients which can greatly skew the numbers. We’ll see how it pans out. One thing is for sure. It has been a weird weather year (again), and it will probably continue for a while. Stay tuned for updates.
Meteorologist: Jeremy Wheeler