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Forecast Discussion:
I'm just about back from my weekend wedding trip - so keeping it a bit short one more day...
The upper air pattern in Figure 1 has a large trough over the western US with plenty of cool air invading southward (the red axis is the trough, the blue is an eastern US ridge). The purple area circled is where the jet is helping lift the atmosphere to create clouds and precipitation. The front, in Figure 2, is sitting along the southern side of my oval region. A surface low and the front is helping to push moisture in an upslope direction across I-25 and up into the mountains where snow has started. Many mountain locations including RMDP and areas near Estes Park and northward above 9000 feet elevation, or so, could see 3-6 and locally 8" or more snow.
Figure 3 paints the rain and snow, shifting northward through the night into Monday to include Longmont and our neighbors with rain; snow continues up in the high country. The total rainfall for Longmont Sunday PM to Monday PM - Figure 4- looks to be in the 1/2 to 3/4's inch area, roughly. The models are all over the place with this cool wet pattern.
The longer range forecast:
Figure 5 is the surface map for Tuesday morning with the low and front sagging southeastward. Some instability remains over the northern I-25 Colorado corridor. The jet stream develops some strange ripples and troughs and another front and good rain chance arrives for Thursday/Friday. More on that later.
