There is a massive gap in meteorology for skiers and snowboarders who like snow.
On one side of the chasm are the long-range predictions about which mountains will see the most snow this winter. We covered this season’s snowfall forecast here, and it’s all about La Nina.
On the other side is the tracking of individual storms and hearing about snowfall forecasts of 4-8” tonight, or if you’re lucky maybe something more like 10-18”. Insert any “that’s what she said” joke here.
It is rare, though, to be able to bridge the gap between a 6-month forecast for the entire winter and the storms that swing through every few days. How are they related? And, like a parent sees pieces of themselves in their child, can we see pieces of the La Nina weather pattern in the last few snowstorms?
Luckily, this week (and next) are shaping up in perfect La Nina fashion, so the time is ripe to tie together the seasonal weather forecast with the snow that’s (hopefully) piling up at your local mountain.
During a La Nina winter, cooler waters in the central Pacific Ocean influence the location of our snowstorms by altering the path of the Jet Stream (wind patterns in the upper atmosphere). Here is the average jet stream track during La Nina compared to winters without a La Nina (see image).
Storms during a La Nina winter often hit the Pacific Northwest and Idaho/Montana, then drop sharply south into Utah and Colorado before tracking up the Ohio Valley and through northern New England. Western mountains from about Lake Tahoe, Utah, and Colorado on north get lots of snow, and northeastern areas in northern New York, Vermont, New Hampshire, and Maine also get plentiful snow with that liquid form of precipitation further south.
So far in mid November, this expected La Nina pattern is taking shape rather well. The three storms traversing the country this week generally fit the La Nina pattern, though they are a bit colder/stronger in the west and a bit warmer/weaker in the east. No matter, these storms bring to life the typical La Nina storm track.
It’s fun to make this tie between a seasonal forecast and the individual storms that bring snow. It’s even more fun to say that this cold and stormy weather pattern – especially for the western mountains, but heading east in time – should hang out for much of the lower 48 for the next 10-15 days. The calendar might say it’s only November, but the weather says La Nina is already here.
Meteorologist Joel Gratz is the creator of http://www.ColoradoPowderForecast.com and is based in Boulder, CO.