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Forecast Discussion:
The cold front is a bit slower than I forecasted yesterday, but is about to cross Longmont around 10 pm Monday night. Snow is already forming west of town and to our north (Figure 1).
By Tuesday morning, the front is down to New Mexico and light snow and mixed ice/snow dominates northern Colorado (Figure 2).
The upper air map by Tuesday PM shows the trough still to our west, so lift continues in the black oval. This seems to be a good 36 hours of precipitation (even if light) over NE Colorado (Figure 3). At that time, the surface map shows the low forming at the four corners position and bands of snow over the Front Range and I-25 folks (Figure 4).
Later Tuesday night, the low is a touch further east, but not much changes up in our neck of the woods (Figure 5). By Wednesday morning, the low has sunk south of Albuquerque and the precipitation is coming to an end (Figure 6).
Figure 7 is the GFS snowfall totals from Monday PM to Wednesday midday - we on the boundary of the 4th and 5th blue hue - that puts Longmont in the 4-5" area. That seems a bit bullish to me and I'm still happier with 1-3" (with some melting).
Tuesday AM Update: At the official reporting time of 7:00am, my home in NE Longmont had received 4.5" of snow. We picked up another 1/2 inch for a total of 5" before that snow band faded out. So my forecast was too low. The GFS print out did well. Forecasts look like just an additional dusting or two to another inch or two is possible over the next 24 hours.
In the longer range:
Things dry out and moderate through the weekend. Temperatures hover just above or just below 50F on through Sunday.
