El Niño phenomenon and snowfall chances in central North Carolina
RALEIGH, N.C. (WNCN) – The official start of winter is still a few weeks away, but it barely snowed last year; El Niño and warm temperatures could have an impact on snow chances this year in central North Carolina.
After digging deeper into the data, here’s the annual winter weather forecast from CBS 17’s Chief Meteorologist Wes Hohenstein.
The alternative this winter: El Niño phenomenon
The big story this winter is the return of El Niño. Although there is a chance of bringing a significant amount of snow to someone, it likely won’t be central North Carolina.
Last year we only saw a few snowflakes in central North Carolina. They fell three different times and left only a trace of snow, the least amount in 17 years. Places like Buffalo, New York got 134 inches of snow and Minneapolis, Minnesota got 90 inches. Then in Charlotte, there was no snow for the first time ever!
An El Niño is forming for the first time in more than four years, and while that typically brings more rain and cold temperatures to central North Carolina, it may not mean more snow due to the record warm temperatures we’ve seen this year.
El Niño occurs when warm Pacific Ocean water collects at the equator. The warm water causes the air above it to warm and rise, causing the calm jet stream to migrate south and east. This results in more active weather in the southeastern United States and changing weather patterns across North America.
In general, El Niño winters lead to wetter-than-normal conditions in the southeastern U.S. and warmer, drier conditions in the north, but active weather during El Niño doesn’t necessarily mean more snow here.
In years where we have been tracking El Niño conditions (since 1950) and La Niña adverse weather events, there is hardly any difference in our snow totals locally. In El Niño years the triangle averages 6.8 inches of snow and in La Niña years it averages 6.1 inches.
“So, it’s difficult to factor El Niño alone into our forecast for snow this year based on a 0.7 difference,” but the record warm temperatures we’ve seen this year will play a big factor.
High temperatures and winter weather history in the Triangle area
For the first 10 months of this year, the Triangle is on pace for the warmest year on record, and those records go back to 1887. This includes the warmest February on record, and the top 10 warmest January, April, July and August.
This continues the trend of our locally warming climate over the past 60 years. Our average winter temperatures have risen more than six degrees from an average of about 40 degrees in the 60s to just over 46 degrees so far this decade.
Warmer temperatures mean a decrease in the amount of snow that can be skied over the years. The average all-time snowfall in the Triangle since 1887 is 6.9 inches. Although over the past 50 years the average has dropped to 5.7 inches, in just the last 10 years the average has averaged only 4.1 inches, a clear downward trend.
The story is the same in the ocean as it is on land. Since the 19th century, the Atlantic Ocean has been consistently warm, and since it is only 100 miles from the Triangle, this has a major impact on our winter weather. A warmer ocean can help keep the air above land above freezing as a winter storm gathers, meaning more rain than snow.
Chances of heavy snow are unlikely
Snow lovers fear not, remember that just five years ago we had 9 inches of snow in one storm? It was an El Niño winter. Plus, we’ve never had a winter without snow.
Last winter was the third warmest on record, and we still managed to get something, so it’s unlikely we won’t snow at all, but it will be difficult to get significant snow.
There will be shots of cold air, just like there was in early November, but good amounts of snow seem unlikely.
At the end of the season, there won’t be enough cold air and moisture combined to give us significant amounts of snow, and for the fifth winter in a row, we will have below-average snow amounts in the Triangle, likely less than five inches.
High temperatures and above average rainfall
CBS 17’s official winter weather forecast keeps temperatures warm, not that we won’t get any cold, but it’s generally warmer than average. Although El Niño winters are usually colder, the last five seasons have been warmer here!
El Niño winters are typically wetter here, so precipitation will be above average, but it will mainly be cold rain and fortunately it will make a significant impact on the drought we are experiencing.
The National Oceanic and Atmospheric Administration (NOAA) recently released its forecast for winter, and its forecast for North Carolina has us warmer than average and wetter than average, which is typical for North Carolina in El Niño years.
If we are going to have snow, it will likely come later in the winter if you take into account the latest monthly temperature forecasts from the European Forecast Model. It keeps us warm in December, but makes us cooler from January through February.
El Niño is the same weather pattern that was supposed to give us a below-average hurricane season, but incredibly warm ocean waters were able to overcome that and gave us more than 20 named storms. Likewise, I think our warm temperatures will once again overcome the old winter and keep our snow amounts very low.