Overview: An approaching wave will spread clouds over the area and draw some colder air to our east back towards the mountains tonight. Areas of low cloud cover, patchy fog and freezing fog will likely develop over parts of eastern Colorado by morning. Over the southeastern plains it is possible that some freezing drizzle or light freezing rain will develop and near the mountains some flurries or intermittent light snow showers will be possible through early Friday morning. As the upper level system intensifies Friday and Saturday the wind will increase and for some areas precipitation will become more likely.
Tonight: Increasing clouds this evening with areas of low cloud cover and patchy fog/freezing fog developing mainly along and north of the Arkansas River late. Over the southeastern plains some areas of freezing drizzle or light freezing rain are possible by morning while a few flurries or light snow showers may develop over and near the mountains. For our major population centers it does not appear we should expect any heavy, widespread precipitation for the Friday morning commute, but fog could significantly reduce visibility and freezing fog could make for a few slick spots over some bridges and overpasses. By morning we expect the air will have cooled into the 20s for most of eastern Colorado with some single digits and teens over the mountains and high mountain valleys.
Friday: Patchy fog and freezing fog will likely hold on early in the morning for the plains along and north of the Arkansas River while some freezing drizzle or freezing rain may fall more steadily over the southeastern plains. By afternoon the freezing drizzle and freezing rain over the southeastern plains could switch to a mixture of wet snow and rain while scattered snow showers will become more likely for areas along and west of I-25. Right now it's hard to pick out an area where accumulating snow is most likely since the precipitation will be somewhat showery in nature over the eastern part of the state, but as the leading upper-level wave with this system approaches the area during the day it’s possible that some areas could receive snowfall accumulations on the order of 1"- 4" under any heavier bands of snow. Accumulating snow and widespread winter driving conditions look more likely over the high country on Friday, particularly over the southwestern part of the state. The air should remain pretty chilly for much of the day with most areas in eastern Colorado only warming into the 30s although a few spots on the other side of the Palmer Divide could reach the 40s for a short time during the afternoon. After a lull Friday night, a period of wind driven snow will likely affect parts of eastern Colorado on Saturday.
Extended: As the upper wave intensifies Friday night into Saturday it will move to our east, draw more cold air down from our north, and increase the wind for most areas. There will be some accumulating snow on the backside of this system, but the position of the developing circulation is not certain and the terrain will likely impact where the snow will fall locally. Right now it appears that residents on the higher terrain around Colorado Springs and Pueblo stand the best chance to receive a few inches of wind driven snow on Saturday while the typical “doughnut hole” that occurs with a strong northerly flow minimizes the impacts from snow for Colorado Springs and Pueblo proper. For now our best advice to holiday travelers is to expect winter driving conditions over the high country Friday and Saturday and possibly over the higher terrain along and west of I-25 late Friday night and Saturday.
The storm should move out of the area on Sunday leaving us mostly sunny but chilly. We'll expect another mostly sunny, cool day on Monday with a few more clouds and slightly warmer air on Tuesday, which is of course New Year’s Eve. For New Year’s Day (Wednesday) many areas should warm into the 40s in advance of another wave that looks to kick up the wind, cool the air and bring a chance for at least scattered snow showers back to the area Wednesday night and Thursday.