SAN JUAN MOUNTAINS WEATHER: MAYBE A LITTLE NEW SNOW?

09 Jan SAN JUAN MOUNTAINS WEATHER: MAYBE A LITTLE NEW SNOW?

The next low pressure system is moving down the coast from the Pacific northwest today as the flow aloft turns southwest.  Mostly sunny skies bring warming temperatures as the storm moves south today.  Southwest flow will increase overnight as the trough moves into the Great Basin with a cold front moving in from the west late Thursday causing increased mountain winds.  Tomorrow we’ll see increasing winds, cloudiness, cooling temperatures and light snow south.

By late Thursday afternoon we should see light snowfall in the southern San Juans and by early Friday morning the strong, cold Pacific trough will be moving through western Colorado carried by a 150 KT jet.  This SW flow will temporarily entrain subtropical moisture that could push  impressive precipitation rates for a 4-6 hour period over the southern San Juans.  Favored SW aspects could see 12″ or more of low density snow.

This storm will quickly move into NW Colorado and by Friday evening the main upper low will have moved downstream.  A secondary disturbance drops south but with very little influence on the southern mountains.  Saturday through Tuesday a very cold air mass camps out in the intermountain region.  By Monday another trough is carved out of upstream Canadian energy over southern Cal and Arizona.  Fairly good agreement of several models showing possible light snow for SW Colorado but maybe favoring N. Arizona and New Mexico… too far out to tell.