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Next Storm/Next Snow Forecast Discussion from the Cherrywood Observatory – December 4-5, 2019

This content was originally published by the Longmont Observer and is licensed under a Creative Commons license.

In Brief:

Another (deep southwest) storm will effect Colorado Thursday, but don't look for much snow from it in town. We get pretty warm for the weekend (relatively speaking) and sink into the ice box for most of next week.

Forecast Discussion:

Moisture is getting pumped up into the desert southwest (again) but not as strongly as we saw in our last storm (Figure 1). The approaching trough is not as significant either and will remain fairly far south as it passes the state (the L and red trough line over California and south in Figure 2). Down slope winds warmed us to surprising levels - lower 60'sF- and gave everyone a boost towards snow melt/removal on Tuesday. It doesn't look as warm leading up to the Thursday morning to midday storm (Figure 3).

The Longer Range Discussion:

The weatherunderground model gives us snow chances as temperatures rise from around 28F to near 40F (Figure 3). This won't help the snow stick. This model even paints the significant accumulation of precipitation as rain, not reaching 1/10th inch.

The GFS gives the southwest mountains (through Friday night- Figure 4) and the northern mountains a nice coating of snow, but its eastward extent ends near or in Longmont. No real snow will hit the Plains this time. The GEM also puts us right on the line too, between snow and no-snow (Figure 5). Finally, the NAM does give us a coating to maybe an inch, but the no-snow zone is very close to the east.

We warm up nicely and dry out for the weekend (no problems getting to and from Christmas parties). But get really cold overall next week as a trough moves in and stays a while in the West (Figure 3).

Figure 1: the water vapor satellite image (browns/reds are dry air, whites and light grey is moist air, purple/blue is ice and high cloud tops). From the the weather channel from Tuesday PM.
Figure 2: The 500mb forecast upper air analysis for Wednesday night. Pink dot is Longmont. Red lines are troughs, blue lines are ridges.
Figure 3: the graphical forecast for the next 10 days for Longmont, CO from weatherunderground.com
Figure 4: 10:1 (snow to liquid) snowfall totals through through Friday PM from the GFS and weather5280com for Colorado made Tuesday afternoon.
Figure 5: 10:1 (snow to liquid) snowfall totals through Friday evening from the GEM and tropicaltidbits. com for Colorado made Monday morning.
Figure 6: 10:1 (snow to liquid) snowfall totals through Friday evening from the NAM and tropicaltidbits. com for Colorado made Tuesday morning.

Current Weather

Mostly cloudy

Mostly cloudy

59°F

UV Index
0 Low
Pressure
29.74 Falling
Visibility
8 miles
Dewpoint
23 °F
Humidity
26%
Wind
W 4.3 mph
Gust
13.3 mph
Wind Chill
59 °F

Hourly Forecast

Today
7 PM
58°F
Intermittent clouds
Today
8 PM
55°F
Intermittent clouds
Today
9 PM
51°F
Intermittent clouds
Today
10 PM
48°F
Intermittent clouds
Today
11 PM
45°F
Intermittent clouds
Tomorrow
12 AM
43°F
Intermittent clouds
Tomorrow
1 AM
41°F
Intermittent clouds
Tomorrow
2 AM
39°F
Intermittent clouds
Tomorrow
3 AM
38°F
Intermittent clouds
Tomorrow
4 AM
37°F
Intermittent clouds
Tomorrow
5 AM
36°F
Intermittent clouds
Tomorrow
6 AM
34°F
Intermittent clouds

7 Day Forecast

Partly sunny

Thursday

65 °F

Partly sunny


Intermittent clouds

Thursday Night

34 °F

Partly cloudy


Partly sunny w/ showers

Friday

53 °F

Cooler with times of clouds and sun; a couple of showers late in the afternoon


Showers

Friday Night

33 °F

A couple of showers in the evening; otherwise, cloudy


Mostly cloudy

Saturday

60 °F

Mostly cloudy


Intermittent clouds

Saturday Night

36 °F

Partly cloudy


Intermittent clouds

Sunday

62 °F

Times of sun and clouds


Mostly cloudy

Sunday Night

33 °F

Becoming cloudy


Showers

Monday

52 °F

Cloudy and cooler with occasional rain; windy in the afternoon


Intermittent clouds

Monday Night

29 °F

Windy in the evening; partly cloudy


Sunrise and Sunset

Sunrise
6:50 AM
Sunset
7:22 PM

Based on AccuWeather data