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Forecast Discussion:
I'm publishing early as the storm is getting underway Sunday afternoon and will extend through the next 48+ hours. Snow is beginning to form in up-slope flow, up and down I-25 already. Figure 1 shows that snow will begin everywhere by 6 pm. There will be on and off light snow showers with dropping temperatures through Wednesday am.
Figure 2, the HRRR, only has a trace to coating of snow by 4 am (so this won't be a massive snow storm in any way). Over the next 24 hours, the forecasters at weather5280.com give us a trace to 3 inches.
The longer range forecast:
Going out to Wednesday pm the GFS (Figure 4) has us receiving 1-2 inches of snow. Note that snow ratios will be higher than 1:10 since temperatures will be so low. The snow will be fluffier and deeper for the same amount of water.
The NAM, for the same time period, has us receiving 2-3 inches (Figure 5). We stay chilly through Saturday with another system bringing snow in Friday. More on that later! Stay warm as highs sit in the teens Monday and Tuesday and lows drop to the single digits again.