WEATHER NEWS: D.C. winter weather forecast 2022-2023: Here’s how much snow to expect
After Washington’s coolest October since 2006, the first third of November stole the show with unseasonably warm air, as temperatures soared into the 70s and even 80s. But Sunday brought a sudden shift to colder conditions reminding us of the inevitable: Winter is coming.
With the Dec. 1 start of meteorological winter just about two weeks away, it’s time for our annual seasonal outlook.
Snow lovers are unlikely to be pleased, as we’re predicting somewhat below normal snowfall for the sixth time in the past seven winters. But we don’t expect a total dud; there should be plenty of storms to track.
We project we’ll have three or four accumulating snow events in the immediate area, with a couple more in our colder suburbs. This doesn’t include dustings or ice events; we are likely to have some of those, too.
Most of our wintry weather will probably come from clippers, which are moisture-lacking systems that sweep into the area from the northwest. They typically only produce a dusting to a couple inches of snow.
We also anticipate seeing storms that cut to our west, which predominantly produce rain. However, when there is enough cold air in place ahead of such storms, the precipitation can start as snow before changing over to an icy mix or plain rain. These are tricky forecasts, and we think we’ll have our share of them this winter.
The odds of a blockbuster nor’easter coming up the coast and walloping us with historic amounts of snow is lower than average, but can’t be entirely ruled out.
We see winter getting off to a pretty benign start. We haven’t received more than 2 inches of snow in December since 2010, and chances are decent that the streak will continue.
Temperature-wise, we’re leaning toward slightly milder than normal conditions overall, but with one colder month.
We’re forecasting January to be our coldest month with respect to normal and coldest overall. That’s when brief arctic plunges could provide several windows of opportunity for snow. We lean toward temperatures moderating in February, but we’d still expect some wintry weather in what’s typically our snowiest month, even if nothing remarkable.
Overall, we expect temperatures for December through February to be around one degree warmer than average.
December: 1 degree warmer than average
January: Around average to one degree below average
February: 2 degrees warmer than average
Our snowfall projection covers November through April. Overall, we expect slightly to somewhat below-average snowfall.
Reagan National Airport (DCA): 6 to 10 inches (compared with a 13.7-inch average)
Dulles International Airport (IAD): 10 to 15 inches (compared with a 21-inch average)
Baltimore-Washington International Marshall Airport (BWI): 8 to 12 inches (compared with a 19.3-inch average)
Fairfax, Loudoun, Montgomery counties: 8 to 18 inches
Alexandria, Arlington and Prince George’s counties and the District: 6 to 12 inches
Snow probabilities at DCA:
6 inches or less: 30 percent
6 to 12 inches: 30 percent
12 to 18 inches: 25 percent
18 inches or more: 15 percent
Although advances have been made in seasonal forecasting, there is still a great deal of uncertainty and limited skill in developing these outlooks. These remain low-confidence forecasts.
Note that monthly temperature predictions are less reliable than for the whole season. A cold or warm pattern lingering a week too long or ending a week early can greatly alter a monthly average. Furthermore, it takes only one big snowstorm for us to reach or exceed our seasonal average.
Answers to questions you may have
What are other forecasters predicting for the Washington region?
TV meteorologists in the Washington region seem to be divided on snow prospects. Forecasters at FOX5 and WUSA9 are projecting near normal amounts but Doug Kammerer at NBC4 is calling for a dud. Here are their numbers:
Along with the paltry snow, Kammerer is also predicting an exceptionally mild winter. “This winter could wind up in the top five warmest in our history,” he wrote.
WUSA9, meanwhile, is calling for near average or “a tad below” average temperatures; FOX5, like us, expects temperatures a little above average.
What is your long-term track record with these winter outlooks?
We have been doing winter outlooks since 2005-2006 and have evaluated ourselves after the fact for the past 17 winters. We’ve generally been in the ballpark, giving ourselves an average grade of around B- or C+, although we’ve had notable triumphs and misses.
Last year, we predicted near-normal temperatures and slightly below-average snow. We were on the money with our snow forecast, but relatively mild conditions meant our call for near-normal temperatures was off. We graded our outlook a B- or C+.
We do take these long-term trends into account in our winter outlooks.
Aren’t weather forecasts only reliable out to about eight to 10 days?
It is true that there is no skill in predicting specific conditions, such as the exact temperature and amount of rain or snow for a given day, more than eight to 10 days into the future. However, seasonal forecasting advances allow us to make educated guesses on the overall tendency of conditions, such as how temperatures and snowfall will compare to average over a month or a period of several months. Because of the uncertainty involved, we give ranges and attempt to be as transparent as possible in conveying that these outlooks are indeed low-confidence.
Below are some, though not all, of the factors that we considered in determining conditions for this upcoming winter.
No single factor tells the whole story, nor are the correlations between past conditions and future conditions — which we used to inform the outlook — always strong. But we have chosen factors that have proved to have at least some predictive value in the past. And when considered collectively, they help paint a picture of what we believe is most likely to happen this winter.
Although no two winters are identical, we expect this one to share some similarities with those of 2008-09 (snowfall: 7.5 inches) and 2011-12 (2.0 inches). These analogues helped to loosely form the basis of our temperature and snow predictions because the weather in those years had some similarities to the factors below.
We are experiencing a moderate La Niña event which is indicated by colder-than-average ocean temperatures in the tropical Pacific Ocean.
In our region, La Niñas, particularly moderate to strong events, are often associated with dry, mild winters with modest snowfall. This is usually because of two primary factors:
1. The frequent presence of a southeast ridge. It is a persistent area of high pressure near Bermuda that pumps mild air into the region and pushes the storm track to our north and west.
2. A dominant northern jet stream and lack of a subtropical jet. Prevalent storm tracks along the northern branch of the jet stream typically cut to our west and/or redevelop as coastal storms to our north, and we are left either warm and rainy, or dry.
Usually in weaker La Niña events, we experience frequent and often brief oscillations from warm to cold and back again, although the cold outbreaks are typically dry. However, not all La Niñas are the same, and there are other factors that drive our weather.
This winter, we expect La Niña to weaken some but for a weak to moderate event to persist through the winter.
La Niña events, on average, bring less snow to Washington than El Niños when ocean temperatures in the tropical Pacific are above normal, fueling storms that move across the southern U.S. However, the La Niña winter of 1995-96, which left behind 46 inches of snow, is a reminder that La Niñas can be snowy once in a while.
The Pacific Decadal Oscillation (PDO) is a measurement of the intensity and location of sea-surface temperature differences from normal in the North Pacific. When it is strongly positive, it often correlates with a cold and stormy pattern for the Mid-Atlantic. When it is sharply negative, conditions often, but not always, trend warm and dry.
We are in the midst of a very persistent negative PDO period. Additionally, La Niña often lends itself to a negative PDO. We expect that this winter the PDO will average negative, perhaps strongly so.
A negative PDO would favor a dip in the jet stream over western Canada with a southeast ridge, favoring a mild weather regime in the Mid-Atlantic, though we expect that pattern to flip at times, usually briefly.
Arctic Oscillation (AO) and North Atlantic Oscillation (NAO)
The AO is a measurement of surface air pressure at the high latitudes over and north of Greenland. Pressures lower than normal indicate the positive phase, and pressures higher than normal, the negative phase.
During the positive phase of the AO, cold air is characteristically locked up over the Arctic by a strong polar vortex, and the mid-latitudes tend to be mild. In the negative phase of the AO, the polar vortex becomes disturbed, and cold air outbreaks become more likely over the mid-latitudes, including the United States.
The AO’s cousin, the NAO, is technically a measurement of the differences in air pressure over the North Atlantic Ocean. It is often indicated by either low pressure (positive phase) or a high-pressure area (negative phase) over or near Greenland. Often, though not always, the AO and NAO share the same phase, especially when averaged over the course of the winter.
A negative AO in the winter months often correlates with a cold pattern in our region, and supports winter storms when other factors align with it, particularly when we have a negative NAO as well. This was the major factor in our historically snowy winter of 2009-10.
High pressure over Greenland or high-latitude blocking helps push the storm track farther south and east, often creating storm tracks that are cold and snowy for our region. While a negative AO and NAO combination far from guarantees a cold and snowy period, our chances of a meaningful snow event are much greater than without it.
On the other hand, a positive AO and NAO combination typically supports a warmer pattern, with a storm track that will often go to our west.
We predict the AO and NAO to average slightly to somewhat positive overall this winter. However, it’s probable that there will be windows when the indexes go sharply negative, enhancing our chance for snow events.