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Forecast Discussion:
The heat ends and the next cold front moves in around dawn today (this post goes live at 1am). From Figure 1, you can see that the warmest temperature for today happened a minute after midnight. Figure 2 shows the departure from normal -cold temperatures in blue -for midday today. The NWS expects that cold air to bump up against the foot of the foothills (my blue line and question marks). Where low clouds form, mainly north of Denver and possibly around Longmont or I-25 and then eastward, there will be periods of freezing drizzle. If it gets dark outside, expect a thin coating of ice. (Thank you Matt Makens on Twitter @MattMakens). Freezing drizzle and snow chances increase during the evening commute then become a pretty extended period of light snow showers much of Saturday.
It isn't much water or snow (1-3" when all is done) but it is suddenly cold and any ice that glazes things first, will make travel a mess.
Figure 3 is the temperature departures from normal for midday Saturday. You can see that the cold air is just deep enough to drain into the mountain valleys and passes.
The longer range forecast:
The graphical forecast from China's weather service has us cloudy through Saturday night with the greatest chance of light to moderate snow showers after 2pm on Saturday (Figure 4).
Figure 5 is the GFS take on snowfall totals. It has us in the 1-2 inch range by Sunday morning.
Figure 6 is the WPC 50th percentile probabilistic forecast. We are in the 1-2 inch area there by Sunday night.
Note, in Figure 1, our Tuesday-ish storm is performing the standard fade-to-nothing trick.
