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In Brief:
While 1 inch of snow has built up on grassy surfaces in Longmont, 1-3 inches of additional snow is possible overnight ending/changing to rain showers in the mid-morning Tuesday. Rain showers continue through Thursday AM. We warm to the 70'sF and dry out for the weekend.
Forecast Discussion:
The storm is underway. I have about 1 inch of snow on my rapidly greening grass. Snow will continue off and on through the night Monday into Tuesday morning. By 11am, we will be up to about 42F. The snow should change to rain around then. We keep warming to the lower 50'sF into the afternoon.
How much snow is left to fall in Longmont? The storm is large and very wet, but rainfall isn't far away to the south in the morning (Figure 1). The heavy snow period occurs before dawn Tuesday (Figure 2). The weatherunderground.com model has 1-3 inches yet to fall. The GFS (Figure 3) give us about 2 inches by dawn. The HRRR (Figure 4) gives us about 2.5-3 inches. That seems like a pretty good consensus. The GEM (not shown) also has about 2 inches but the NAM (not shown) gives us 7 inches. I think one of these models is not like the others.
I will point out that we never had a period of rain, as I predicted. I'm slapping my wrists.
The longer range forecast:
Rain showers continue from Tuesday to Thursday afternoon now and then. We warm to the 60'sF Thursday and the 70'sF for the weekend.
In the distant distant future (next Monday-Wednesday) there is another stormy and wet period possible. More later!
