In the last 24 hours, both the Canadian model and the GFS model have been envisioning a big finish to the prolonged snow event for the Rockies, wherein the last of the moisture from the AR event, rides on the jet over the Four Corners and the jet kinks and turns from zonal (westerly) flow into southwesterly and dumps some decent snow over most of the area.
Snow showers could break out Friday primarily above 8,500′ from just south of Purgatory to the north. Saturday heavier snow could fall in the areas favoring the westerly flow, then Sunday very early, in the GFS and Canadian scenario, heavy snow would fall everywhere but would favor us in the south.
I like what those two models are doing, yesterday before the models saw this, I mentioned that if the cold air is in place before the moisture arrives it can get fun. That is exactly what the GFS and Canadian depict. I would really like to see Euro pick up on that. Currently, the Euro downplays the amount of moisture available and takes the jet too far south. That makes a huge difference with the snow totals.
Here is the Euro from last night you can see the enhanced snowfall to our south
Contrast that with the GFS model
And the Canadian
This has prompted the NWS to issue a Special Weather Statement (SWS) which is usually the precursor to a Winter Storm Watch. If the Euro gets on board today I think we may see a loosely worded blanket Winter Storm Watch for a prolonged event.
Here is the SWS
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
550 AM MST WED DEC 11 2019
ELKHEAD AND PARK MOUNTAINS-UPPER YAMPA RIVER BASIN-
CENTRAL COLORADO RIVER BASIN-
GORE AND ELK MOUNTAINS/CENTRAL MOUNTAIN VALLEYS-
WEST ELK AND SAWATCH MOUNTAINS-FLAT TOPS-
UPPER GUNNISON RIVER VALLEY-NORTHWEST SAN JUAN MOUNTAINS-
SOUTHWEST SAN JUAN MOUNTAINS-
INCLUDING THE CITIES OF COLUMBINE, HAHNS PEAK, TOPONAS,
STEAMBOAT SPRINGS, EAGLE, EDWARDS, GLENWOOD SPRINGS, CARBONDALE,
BASALT, ASPEN, VAIL, SNOWMASS, CRESTED BUTTE, TAYLOR PARK,
MARBLE, BUFORD, TRAPPERS LAKE, GUNNISON, CIMARRON, TELLURIDE,
OURAY, LAKE CITY, SILVERTON, RICO, AND HESPERUS
550 AM MST WED DEC 11 2019
THE INLAND INTRUSION OF AN ATMOSPHERIC RIVER NOW MAKING LANDFALL
OVER SOUTHERN OREGON AND NORTHERN CALIFORNIA IS EXPECTED TO BRING
WIDESPREAD SNOWFALL TO THE MOUNTAINS AND HIGH VALLEYS OF WESTERN
COLORADO FROM LATE THURSDAY THROUGH THE WEEKEND. THIS STREAM OF
MOIST PACIFIC AIR HAS THE POTENTIAL OF GENERATING AS MUCH AS TWO
FEET OF SNOW IN THE NORTHERN AND CENTRAL COLORADO MOUNTAINS BY
SUNDAY MORNING. SNOWFALL WILL BE LATER TO DEVELOP IN THE SAN JUAN
MOUNTAINS AND, AS A RESULT, AMOUNTS THERE ARE EXPECTED TO BE A
BIT LOWER WITH AMOUNTS OF 12 TO 18 INCHES POSSIBLE BY LATE SUNDAY
NIGHT. IN ADDITION TO SNOW, STRONG WINDS IN THE HIGH COUNTRY ARE
LIKELY TO GENERATE WIDESPREAD BLOWING AND DRIFTING SNOW.
TRAVEL OVER THE HIGHER MOUNTAIN PASSES OF WESTERN COLORADO IS
LIKELY TO BECOME DIFFICULT OR HAZARDOUS FROM THURSDAY THROUGH THE
WEEKEND. THOSE WITH PLANS TO TRAVEL OVER RABBIT EARS, VAIL,
SCHOFIELD, MONARCH, RED MOUNTAIN AND COAL BANK PASSES SHOULD BE
PREPARED FOR WINTER DRIVING CONDITIONS. TAKE PROPER PRECAUTIONS IF
TRAVELING DURING THIS TIME PERIOD AND STAY TUNED FOR UPDATES ON
THIS DEVELOPING WINTER STORM.
One thing I like about the GFS its model runs span 16 days, instead of 10 like the Euro and Canadian. I am already starting to see signs of a Christmas storm, too early to be too confident but I will be watching. There are also signs of a chance of snow before that around the 20th!
Thanks for following!