SAN JUAN MOUNTAIN WEATHER: WINTER COMING?

07 Dec SAN JUAN MOUNTAIN WEATHER: WINTER COMING?

Thursday’s minor weather event was the beginning of the end of our incredibly warm & dry autumn in the San Juan and the start of colder winter weather this weekend.  Today a strengthening polar front is pushing into Wyoming carrying dramatically colder air and snow into the northern Rockies.

Models are in agreement for a strong winter storm delivered by a southbound 150+ KT jet that will drive the cold front into the forecast area by Saturday night favoring the northern and central mountains and the northwest facing terrain of the San Juans.  By Sunday afternoon the storm wanes with drying from north to south but allowing continued snow showers in our SW mountains through the second game of the afternoon.

The central and northern mountains might see 12″ or more of snow but the San Juans probably won’t see significant accumulations.  NW facing elevations above 11,000′ might receive 4-8″ or more in favored locations, but the downside of the equation will be heinous WNW winds driving the snow into hazardous slab conditions.  Also as colder air infiltrates Sat. night, clearing skies on Sunday evening and radiational cooling will bring single digit and below zero temps to the mountains with day time highs 5 to 10 degrees below normal Sunday and Monday.  The good news, a warming trend will slowly moderate the temperatures during the coming week.

Next week will bring more unsettled weather but right now looks to favor the forecast area north of the San Juans.  It’s just too chaotic and far into the future to forecast right now.