One of the most anticlimactic events of the year is when the National Oceanic and Atmospheric Administration issues the U.S. winter outlook in October, because anyone who has paid attention to the El Niño/La Niña outlook during the prior six months knows exactly what the maps are going to look like.
The annual forecast dropped two weeks ago and, yes, it looked exactly like the maps always do with an expected La Niña (cooler than normal equatorial Pacific sea surface temperatures) — a tilt of the odds to warmer than normal across much of the East, including Virginia, and a lean toward drier than normal across much of the South, edging into southern Virginia, most of the state in the “equal chances of wet, normal and dry” middle ground.
Persistence forecasting, or the presumption that recent patterns will continue unless proven otherwise, would lead us to similar thoughts about the coming winter.
In the Southwest and Southside Virginia coverage area of Cardinal News, we have had two consecutive winters with very little of anything really wintry occurring, part of what is essentially a five-year period when wintry weather has been sporadic and often outright absentee.
Last winter was a one-hit wonder for snowfall in most of our region, as a Martin Luther King Jr. Day winter storm on Jan. 15 brought 3 to 8 inches over much of our coverage area. The exception was Southside Virginia, where places like Martinsville and Danville were excluded from the Jan. 15 storm as a warm-front-like feature nudged the snow band to the north and focused it with surprising intensity along the Blue Ridge. What was expected to be 1- to 2-inch amounts from Floyd County north into the Roanoke Valley instead turned into 3 to 6 inches, while areas west of Interstate 77 got a more expected 4-8 inches with a few locally heavier amounts.
A notable period of cold weather followed for about a week, but a second potential winter storm mostly missed our region to the north, as did a couple more with a weaker mid-February cold air shot.
Incredibly, Martinsville and Danville got even less seasonal snowfall in the 2023-24 winter — zilch — than the decimal amounts those locations got in what came close to being a regionwide snowless winter in 2022-23, saved from a shutout by a mid-March dusting for many locations.
Another low-snow winter?
NOAA’s winter forecast suggests there are pretty strong odds of a low-end snowfall winter happening for the third consecutive year and the fourth of the last six in most of our region.
In March, we pondered whether the recent run of mostly mild, snow-challenged winters specific to our region, a rather sudden shift from the 2009-18 period that brought several relatively snowy winters and multiple large winter storms, was driven primarily by natural cycles, climate change, or the answer that would be given by most meteorologists and climatologists, natural cycles affected by climate change.
The El Niño Southern Oscillation between warm-water El Niño and cool-water La Niña in the equatorial Pacific (and presumably some neutral years in between, though these have not happened much lately) is perhaps the natural cycle most often cited in winter forecasts and analyses. However, it is far from the only climatic factor affecting our winter, though often it is one of the most stable and predictable ones through the length of the season. With a relatively small sample size going back a few decades, correlations between La Niña, El Niño and regional weather patterns are still pretty loose overall and are not always conclusive.
It’s also important to remember that winter lasts three months with another six weeks or so on either side containing potential for winterlike weather, so it is often the case that different segments of the winter have weather that varies substantially from whatever the seasonal average turns out to be. Having a mild, dry winter on the whole can sometimes be eclipsed in our perceptions by getting one large snowstorm or a couple of weeks of deep-freeze temperatures accompanied by intermittent snow and ice.
Beyond these, there are some other caveats to consider with a La Niña-focused winter forecast.
La Niña hasn’t actually developed yet
The biggest problem with a winter forecast based on La Niña is that, well, there isn’t a La Niña yet.
The latest three-month Oceanic Niño Index is -0.1, meaning the average sea surface temperature of a key region of the equatorial Pacific averaged 1/10 of 1 degree Celsius cooler than normal from July through September. To become an official La Niña, the ONI must reach -0.5 for three consecutive overlapping three-month cycles. Even if the August to October cycle hits the -0.5 threshold (appears unlikely), the absolute earliest a La Niña could be declared now is January, though the stripe of Pacific equatorial waters may cool enough to influence La Niña-like effects before then (and some would argue it already is.)
Coming out of the El Niño in spring, there were some pretty strong forecast model signals that La Niña would not only be present by now, but quite strong. That didn’t happen. The Climate Prediction Center still gives La Niña a 60% chance of developing, but it is far from certain that it will.
If it does happen, La Niña is likely to be weak
It appears increasingly likely that if La Niña develops it will be on the weak end of the spectrum, not a particularly strong one. Historically, weak La Niñas are correlated with a wider variety of winters than stronger ones, which more commonly tend to be milder and drier.
Examining six weak La Niña winters since 1991, the National Weather Service office in Blacksburg found that those averaged near-normal to a little colder than normal in temperature through its forecast area, but a bit dry.
However, one of those weak La Niña winters was an epic one, in 1995-96, with a massive regionwide 18- to 36-inch snowstorm in early January, another with some foot-plus amounts in early February, and up to 10 inches in an early December storm. The 1995-96 winter ranks as Lynchburg’s snowiest on record, going back to the early 1890s, with 56.8 inches, and is officially Blacksburg’s snowiest with 67.4 inches in a similar time frame (missing data in February 1960 likely robs that winter of being Blacksburg’s actual snowiest in the record book). It’s tied for second at Roanoke with the 1986-87 winter at 56 inches, dating to 1912, trailing only the 62.7 inches of the aforementioned 1959-60 winter.
The 1995-96 winter, not ancient being within the past 30 years, is one to pull out of history’s hat for snow lovers seeking hope during dismal La Niña winter forecasts.
Recent La Niña winters have had notable cold, snow and ice
As we mentioned above, winter has often been considered missing in action in most of our region since the Dec. 9-10, 2018, snowstorm that dumped 1-2 feet across almost all of Southwest and Southside Virginia, the most widespread foot-plus snowfall in our region since January 1996. (Memorable big snows for many in December 2009 and February 2014 tended to be less so in Southside.)
But what notable wintry periods we’ve had since 2018 have commonly happened during La Niña, which developed three years in a row before flipping to its warm twin brother El Niño last winter.
The 2020-21 La Niña winter brought a series of light to moderate wintry precipitation events across our region, including a widespread white Christmas along and west of the Blue Ridge, a couple of 4-7-inch late January/early February snows along and west of the Blue Ridge (the second of the two mostly busted right along the Blue Ridge and the Roanoke Valley), and by far the decade’s most extreme ice storm in several Southside counties in February.
January 2022 was the most wintry month we’ve had in the past five winters, with two widespread snowstorms in the 2- to 8-inch range and a couple of other wintry events in an overall cold month that kept the ground white for many days along and west of the Blue Ridge.
And even the almost snowless 2022-23 winter had an extreme three-day Arctic outbreak at Christmas, below-zero and single-digit temperatures accompanied by power-crashing high winds. That takes us to the next point.
La Niña often brings sharp Arctic shots amid mild winter
It is fairly common even in La Niña winters for there to be one or two sharp, but short, Arctic outbreaks during the course of the season.
In fact, the most extreme Arctic cold snap of the past half-century, in January 1985, happened during a La Niña winter, when the state record cold temperature of minus 30 degrees was set at Mountain Lake in Giles County and just about our entire region (and most of the U.S. east of the Rockies) dipped several degrees below zero on Jan. 21.
Decembers during La Niña events in 1983 and 1989 also featured extreme shots of Arctic air with many below-zero temperatures, as did the three-day Arctic blast noted in December 2022.
None of these winters were especially cold or snowy on the whole in our region — and 2022-23 was among the mildest and least snowy — but they did have memorable and impactful Arctic blasts.
Dryness may be the bigger concern than temperature
Many people’s focus in winter forecasts is whether it will get cold enough, frequently enough, to support multiple rounds of snow in our region. But even if it were to get cold often, if there isn’t much moisture to feed into that cold air, it won’t snow a lot, and it won’t rain much either.
We are currently in what has essentially been a yearlong dry trend that has been interrupted by few El Niño-charged wet storms last December and January, three tropical systems in August and September, and a couple other spells of decently rainy weather in between. October has had almost no rain in our region since the remnants of Hurricane Helene moved out three days into the month, and there is little indication of widespread significant rain on the horizon entering November.
If a dry-tilting winter develops as it often does with a La Niña pattern, we could enter next spring and summer in much worse shape with soil moisture and water tables than we did this year, and another hot, dry summer could push us toward severe drought similar to what much of West Virginia and Ohio have experienced this year.
But that’s a big if, just like any projections about cold and snow are.
Soon, it will be time for you to make your own projections in the annual Cardinal Weather snowfall prediction contest.
Journalist Kevin Myatt has been writing about weather for 20 years. His weekly column, appearing on Wednesdays, is sponsored by Oakey’s, a family-run, locally-owned funeral home with locations throughout the Roanoke Valley. Sign up for his weekly newsletter:
