The Latest Update Shows Impact Might Good for Some, Uncertain For Others.
NOAA’s National Climate Predication Center announced that La Nina has returned. She’s weak but still might pack a sting for our winter weather.
La Nina means cooling of water in the eastern Pacific. As remote as that may seem to North America, that coolness effects how weather masses form and move around the globe. As we reported earlier, the Climate Prediction Center said that La Nina hadn’t developed as expected after a record El Nino (warming water) in 2015-16. But just last month, a weak La Nina was detected.
What does that mean for snow forecast? Weather forecasting is about probabilities. A look at the temperature map below (right) reveals that temps are expected to be generally warmer across the lower US and cooler in the Pacific Northwest, Upper Midwest and Ontario. The precipitation map says below normal precip across the southern US, continuing the drought situation there, and above average precip in the upper band across the US-Canada border. This is pretty consistent with the snow forecast we reported on last month. Confirming an La Nina just ups the odds.
So, good news for the Pacific NW and BC, Montana, Wyoming. Uncertainty for just about everyone else.
Remember, these are probabilities and not definitive. Variance will happen. NOAA will update their forecast in a few days. We’ll let you know.