Groundhog update! To quote the CNN headline: “Groundhog predicts an early spring. Don’t get too excited, he’s usually wrong.”
Locally, it was sunny and abnormally warm in Longmont. Today, a Pacific cold/cool front sweeps in with precipitation all across the west, but we’ll see down-slope winds and not much of a cool down and no precipitation (Figure 1). You can see the pressure drop Sunday midday in the black line stretching across the middle of the graphic of Figure 2.
The harbinger of change is up in Canada right now. Figure 3 shows the next blast of fantastic cold much further west than the one that hit Chicago and the Midwest. I’ve drawn in a cold front (pretty bad artwork) on the margin of this invasion.
The longer range forecast:
In Figure 4, the cold air (not as extreme as what we saw the last week out east of us) is flowing over us and invading New Mexico, Texas and Oklahoma on Wednesday/Thursday. We’ll be some 20 to 25° F below normal. With that invasion, we’ll have a period of cold up-slope flow and snow, then colder temperatures for a while. Weatherunderground (Figure 2) gives us 1-3 inches. The GFS (Figure 5) gives us a coating to 1 inch. It is too soon to really say. You’ll have to come back for more!