JR’s San Juan Mountains Weather Report: Update 12/21/10 0800
From the NWS this morning….
SHORT TERM…TODAY THROUGH WEDNESDAY NIGHT…
EXPECT VERY HEAVY SNOWFALL IN THE MOUNTAINS OF WESTERN COLORADO AND EASTERN UTAH THROUGH MID WEEK. SIGNIFICANT SNOW ACCUMULATIONS FROM THIS PROLONGED SYSTEM WILL BE MEASURED IN FEET...MAINLY AT ELEVATIONS ABOVE 8500 FEET.PAC UPPER LOW DIGGING SOUTH OVERNIGHT WILL DEEPEN ALONG THE COAST TODAY AND HELP SHIFT WINDS ALOFT MORE SOUTHWESTERLY. CLOUDS ARE STARTING TO THICKEN AGAIN ON IR SATELLITE IMAGE AS ANOTHER DISTURBANCE MOVING THOUGH THE FLOW THIS MORNING FROM NORTHERN AZ. EXPECT THE SOUTHERN AND CENTRAL VALLEYS TO REMAIN WARM THROUGH THE DAY AS THE CONVEYOR OF WARM MOIST AIR CONTINUES. BEST SNOW CHANCES WILL BE ON THE SOUTHWEST FACING SLOPES ABOVE ELEVATIONS OF 8500 TO 9000 FEET. THIS WILL BE A HEAVY WET SNOW. INTENSITIES AND COVERAGE WILL DECREASE LATER TONIGHT AND EARLY WEDNESDAY AS ONE DISTURBANCE EXITS AND ANOTHER IS POISED TO ENTER THE REGION...ALTHOUGH OROGRAPHICS WILL CONTINUE. WEDNESDAY WILL SEE INCREASES IN SNOW PRODUCTION AGAIN WITH THE NEXT DISTURBANCE TRACKING OVERHEAD AS THE MAIN UPPER LOW EJECTS EAST. So although it's too warm for snow in the lower valley's below 8,000' (Uncompahgre Valley) it is snowing in the alpine and will begin to wind down on Thursday as Kalifornia slips away. JR
"Currently in Silverton: Snowing large flakes S1 ( approx 1/2"/hr). HN24 - 12"/.75" top half is goose feathers. Winds - Calm. Temp 28F. Current on Passes - Added afternoon shift and overnight shift: Molas to Coal Bank reporting 11" - 13". RMP adding up to 6" - 8". The Gorge only 2" - 3". Recent winds have been light but reportedly picking up again toward Molas pass."