La Nina Update

On schedule, today's weak system is passing to our north. The outlook for our next storm is to pass to our south off of the South Carolina coastline on Friday. You can see my outlook on my TV Graphics page (tab above-main web site). Unfortunately for snow lovers the next big storm will be on Sunday- again passing to our west keeping us on the warm side. I'll have more tomorrow.

This winter weather pattern was expected to be governed by La Nina. That is the sister part of El Nino Pacific and water near South America have cooled down to about 2C below normal. This heat is the energy source for the storm track, and net result - the natural warming and cooling of the tropical Pacific Ocean. The animations here show the past month of ocean temperatures, and anomalies (compared to normal), with the Pacific in the center. Clearly a moderate La Nina with the tropical easterlies pushing the warm water to Southeast Asia with temps near or slightly above normal. While the equatorial jetstream for North America. The expectation is on track and you can see the Winter Outlooks through the link at the right. But that is only part of the story. While Pacific storms will crash into the Western US over the next 7-10 days, that would often bring a mild winter for the eastern half of the nation. We can thank the build up of snow in the heartland and central Canada for battling that and keeping us near normal as this happened. The source of our cold- the Polar Vortex is sliding over the pole to Eurasia, but the North Atlantic Oscillation does show modest negative (cold numbers). I will show that tomorrow, but no clear indication with opposing forces over the next few weeks. Just an average end to December.. but storm track currently does not favor much snow for us.
US and Canada Snowpack: