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Forecast Discussion:
An interesting change has occurred in the models this morning concerning the week-end storm, but first we'll be warm today and chilly and windy tomorrow... let's look at it:
Figure 1 shows the upper air pattern from Sunday with the departing low and trough and the approaching ridge. That ridge passes overhead today making things quite warm (the fact that the wavelengths are shorter than the distance between the US east and west coast means they are on the move - progressing eastward).
Figure 2 has Longmont some 18F above normal today! Figure 3, the upper air map for tomorrow, shows the next trough here already here. Figure 4 is the temperature anomaly for Tuesday; Longmont is about 4 degrees below normal. An almost 20F drop in one day will be noticeable!
The longer range forecast:
Figure 5 is the week-end storm. Notice (like yesterday's discussion) how much further south the Low center is on that trough. Colder, slower, and wetter is the story. But, as we can see in Figure 6 the model run from 6am on Sunday has Longmont only receiving a couple of inches of snow (and nothing just down in Niwot)-Figure 6. Compare this to the model run at midnight Saturday into Sunday (Figure 7) and we were getting 8 inches or more. Things are suddenly coming out MUCH warmer for this storm. Back to the model run from later Sunday morning, we are still getting a lot of water (Figure 8) with Longmont getting 1.5 inches of rain or more.
We'll keep on this storm all week.
