WOAY-TV (Oak Hill, WV): The buzz word driving our winter pattern is El Nino, but what’s its status and forecast going forward?
So, first of all, if we look at the sea surface temperature anomalies, they are above average across the entire equatorial Pacific. Notice how the anomalies have increased in aerial coverage and greater heat content has spread across the Dateline. So we have a super El Nino that’s the highest level El Nino you can have.
You can see, especially from April to July, we have had the heat expand from west to east into the equatorial Pacific. The La Nina abated, El Nino has developed. So that’s another signal. Now, when we compare this year to previous years, we look at the sea surface temperature anomaly trends. The best-matched El Nino with respect to current sea-surface temperature anomalies is the 1982-83 winter.
When we look at the outgoing long wave radiation, basically the more negative, the number, the more clouds that develop from the heat content bottled up in the Eastern Pacific. Warmer water leads to more evaporation moisture in the atmosphere and forms clouds. In this case, we are following a similar trajectory to the 1987-88 El Nino.
And a third factor here, 850 millibar anomaly winds along the Equatorial Pacific. This is the strength of the wind at 5,000 feet pushing warm water across the equatorial Pacific. The best-matched El Nino with 850 mb wind anomalies is 2015-2016 winter El Nino.
Additionally, given the lack of cooler water anomalies near the Equatorial Pacific, the transition to La Nina later this year will likely be slower than guidance suggests. The lack of cooler water also implies a Super El Nino will continue through the remainder of winter.
Now, the second driving factor that I think is going to determine how much snow we get is the North Pacific Ocean. This image (see video) shows heat content that has penetrated 150 meters across the north-central Pacific. So we are seeing very strong subsurface warming, which gives way to a negative base of the Pacific Decadal Oscillation (PDO).
Below is a look at our AVERAGE annual snowfall:
Seasonal snowfall amounts with similar El Nino analog years:
Beckley: 43 to 58 inches
Bluefield 13 to 35 inches
Lewisburg: 1 to 33.6 inches
The PDL is going to stay negative. Temperatures in a negative PDO favor warmth in the East and cooler than average temperatures in the West.
Look at these seasonal snowfall amounts with the negative PDO winter:
Beckley: 33 inches
Bluefield: 25.5 inches
Lewisburg: 17 inches
So the overall theme here is that when you couple that negative PDO with the strong El Nino, we will have below average snowfall and it will likely come in one or two storms later in the winter.
