In Brief:
We are on the western edge of a massive cold air outbreak that is hitting the U.S. Some snow.
The Forecast Discussion:
A line between Longmont and Lyons will be the western edge of very cold air that is spreading over the nation (Figure 5). The first shot of cold air hits Thursday keeping temperatures below freezing for a day and a half and light snow on the lower elevations, healthy snow up in the mountains (Figure 1, Figure 2-4).
The low lands should see an inch or less of snow while the mountains get up to 6 inches (Figure 2-4). Even though Friday sees a brief warm up, Thursday, and Saturday through Monday will be very cold. We "might" see a high on Sunday between 0F and 8F (models don't predict extremes well- Figure 5).
This is a fairly extended period of very cold air with a shot of snow Thursday, and Sat/Sun/Mon AM's. If I can narrow down snow amounts better, I'll post it here, but it is a different kind of storm (multiple weak pulses in very cold air).
The Longer Range Forecast:
Over the next 10 days, the low lands (except north of Fort Collins) still won't see much snow, but the mountains will pick up an important 1 -2 feet (Figure 6). After that we warm up to near normal and return to mostly dry conditions (Figure 1).
