Mostly sunny today and Thursday/ Friday into early Saturday a storm hits Colorado with light to moderate snowfall/ Saturday looks colder with mostly sunshine expected/ Sunday and Monday clouds + sun mixed (north) and mostly sun for southwest Colorado

Average temperatures for this time of year ->
Aspen (near 8,000 feet elevation) - Average high; 35 (highest 61 in 1939, lowest 11 in 1916) Average low; 11 (highest 40 in 1977, lowest -19 in 1961)
Fraser (near 9,000 feet elevation) - Average high; 31 (highest 58 in 1939, lowest 01 in 1919) Average low; -2 (highest 29 in 1910, lowest -38 in 1966)
Summit elevations, above 12,000 feet - Average high; 22, Average low; -1

Forecast updated for Wednesday, December 10, 2013 (Updated Wednesday at 4:30am)

High pressure ridging aloft builds in and holds today and Thursday, with a slow warming trend under mostly sunny skies. A low pressure system will be developing across the northwest US at the same time, with this one looking not so strong. Friday into early Saturday we expect a low pressure system to carve south and move through Utah then Colorado (later day). Snow develops, and with modest dynamics and moisture, we expect light to moderate snowfall starting late day Friday and through early Saturday. Saturday looks like a great day to show up! Sunday and Monday we sit under a slightly unsettled pattern, and mostly isolated, light snow showers are possible at times mainly Sunday. Please be sure to log-in and favorite your resort forecasts so you save time. CM

7 day to 2 week+ forecast (since 1998) - 15 to 24 December, 2013 - We expect a shifting pattern, as east Pacific high pressure ridging that has been a very persistent feature this fall breaks down a bit, and the storm track-jet stream cuts more across eastPac waters and into the west coast, with a more zonal (fast moving, west to east) pattern and fast moving storms possible into mid December and beyond. These storms would favor California, Lake Tahoe resorts specifically and the northwest US, with drying and weakening as these storms move into Utah and Colorado, for mostly light to moderate snowfall potential in each storm, though some have heavy snowfall potential. The next storm arrives mid to late next week with another shot of snow for Colorado resort areas. Either way, the pattern stays pretty busy across the west, and this is expected to be good for snow pack and conditions as frequent storms keep the snow coming right through the Christmas holiday period. CM

Longer Range Outlook

Last winter we had a La Nina SST pattern in effect, and our weather was drier than average across the southwestern US, and near to above average snowfall was recorded across the Pacific Northwest. This does not include December, which was near to above average in precipitation for some parts of the southwest US. Christmas and through the rest of the season was pretty dry for most areas including Tahoe.

We do not expect a repeat of last season, this season...

As of now, December 2013, we are continuing to be affected by an ENSO-Neutral, or La Nada Sea Surface Temperature pattern across the Equatorial Eastern Pacific (SSTs near to slightly below average).


The larger time-scale SST pattern in place right now is a cool phase PDO, or negative PDO, which stands for Pacific Decadal Oscillation. This is a more long term pattern (decades), and it has made any recent years El Nino SST patterns weaker. All of this means a couple of things for us. We do not have an El Nino or La Nina SST pattern, so nothing is as clear cut as either of these can be in terms of prevailing weather patterns. A wet Southwest US is not likely (El Nino), and a dry pattern for the southwest US and wet for the Pacific Northwest (usually the case with La Nina) is also unlikely, so we are left with the many potential scenarios in-between, but overall we think all areas will see better than average snowfall and colder than average temperatures.

We expect the ENSO Neutral, or La Nada pattern to continue through at least mid-winter, with a possible trend toward El Nino in the late winter/ spring/ summer of 2014. East Pacific high pressure ridging will be a pretty persistent feature in the early season, possibly through December and into January, with colder than usual storms moving in out of the northwest and not as much out of the west, off the Pacific, for plenty of cold blasts and storms hitting the Rocky Mountains, and the anything goes cut-off low pressure systems also a common feature this winter, through December and into January, giving southwest desert areas, including southern California, some shots at potentially significant snowfall.

Cut-off low pressure systems, though a bit more dicey and hard to predict, can provide many areas across the southwest US including northern Arizona, northern New Mexico, and southwest Colorado with good dumps of snow, so with these storms a good possibility, we could still do pretty well in these areas. Faster moving clipper-type storms are also expected to hit northern Colorado and Utah, Wyoming, the northern Rocky Mountains and on through the Pacific Northwest with some good dumps of snow as well.

-->After the Christmas-New Year rush, the La Nada may start to wear off, being replaced by a weak El Nino SST pattern. This means we could see a strengthening jet stream across the west and eastern Pacific, and increased moisture in general for late winter snow storms as they move in more directly off the Pacific, late January-February and through April. We will keep this outlook updated as more information becomes available. If you want to know when the snow is coming (and be able to set unlimited alerts for any resort), within 5 minutes or less of us (our our sources) entering the data into any of our forecasts, be sure to pick up our high quality iPhone app, which comes with unlimited forecast snow alerts