Monday, January 27, 2014
The current complex forecast has shown signs of stability the past few model runs, increasing confidence that a possible 20-40” long-lasting snowfall event will grace our area for the second half of the workweek and into the weekend.
The Steamboat ski area reported 3” mid at 1pm and 2” up top today, but light snow will continue until about midnight, producing a 4-8” report by Tuesday morning. Tuesday will be a beautiful in-between day before the weather fireworks begin by mid-day Wednesday.
Similar to today, another cold wave drops down the west side of the Hudson Bay vortex and phases with a Pacific wave in the undercutting polar jet stream that is forecast to contain copious quantities of subtropical moisture. Indeed the moisture feed extends all the way from the Hawaiian Islands earning this branch of the polar jet stream the moniker Pineapple Express. The end result is our flow backs from the north to the west, warming temperatures and increasing winds. Snow is currently forecast to begin on Wednesday with periods of heavy snowfall lasting through at least Thursday morning, creating 6-12” by the Thursday morning report.
Most models then slam another undercutting wave into the northern California coast early Thursday, and waves of energy should continue to travel over our area, still interacting with cold waves from the north rotating around the Hudson Bay vortex. There is some uncertainty here, but currently I’m thinking another 8-16” by the Friday morning report if things hold together as forecast.
If the Pacific wave does travel over our area relatively intact, heavy snows will continue through the day Friday followed by moderate to light snow, producing another 6-12” by the Saturday morning report.
During the weekend, the polar jet stream is forecast to buckle and drop a storm into southern California, backing our flow further to the southwest and eventually ending snows by late in the weekend. I would expect another 3-6” by Sunday morning as this storm cycle ends.