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Next Storm/Next Snow Forecast Discussion from the Cherrywood Observatory – December 22, 2018

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

Forecast Discussion:

Closer the front comes... step by step...

With the storm moving in Friday night - I'll post this early so you have a heads-up.

There will be a low forming down in the SE corner of the state that will create some up-slope flow from about 4am to 3pm on Saturday. We seem to be well placed for a coating of snow; maybe up to a local inch of snow in spots. Hurray!

Will it last until Christmas morning?

Figure 1: The forecast surface map for Saturday PM. From NCEP.

The longer range forecast:

The GFS is giving us 1/10th to 1 inch of snow Saturday (as shown above) and that is all that is going to fall by Christmas afternoon (Figure 2). The GEM puts us in the 1/2" area by Christmas afternoon (Figure 3).

After Christmas, more snow is on the way.  As is colder air.  Over the next 5 days (going up to a day after Christmas) we are given 2-3 inches of snow  by the GFS (Figure 4).

Figure 5 is the overview of the next 10 days:

The precipitation Saturday is will last about 10-12 hours then things warm to the mid 40's for Christmas Eve Eve and Christmas Eve - and lower 40'sF Christmas Day. The precipitation won't start again until after about 9pm on Christmas Day and will continue on and off to the weekend.  The initial push on Wednesday is a hefty 3-5 inches according to the Weatherunderground.com model.  As always, more later!

Figure 2: The forecast accumulated snow map from the GFS and weather5280.com for Colorado, through Christmas Day night.

Figure 3: The forecast accumulated snow map from the GEM and tropicaltidbits.com for Colorado, through Christmas Day night.

Figure 4: The forecast accumulated snow map from the GFS and weather5280.com for Colorado, through the next 5 days.

Figure 5: the graphical forecast for the next 10 days forecast for Longmont, CO from weatherunderground.com

Current Weather

Sunny

Sunny

74°F

UV Index
2 Low
Pressure
29.89 Falling
Visibility
7 miles
Dewpoint
42 °F
Humidity
32%
Wind
NNE 3.3 mph
Gust
7.6 mph
Wind Chill
74 °F

Hourly Forecast

Today
6 PM
72°F
Sunny
Today
7 PM
69°F
Mostly sunny
Today
8 PM
65°F
Intermittent clouds
Today
9 PM
62°F
Mostly cloudy
Today
10 PM
58°F
Mostly cloudy
Today
11 PM
56°F
Mostly cloudy
Tomorrow
12 AM
53°F
Intermittent clouds
Tomorrow
1 AM
51°F
Partly cloudy
Tomorrow
2 AM
48°F
Mostly clear
Tomorrow
3 AM
46°F
Mostly clear
Tomorrow
4 AM
44°F
Clear
Tomorrow
5 AM
43°F
Mostly clear

7 Day Forecast

Mostly sunny

Wednesday

75 °F

Mostly sunny, pleasant and warmer


Partly cloudy

Wednesday Night

41 °F

Patchy clouds


Mostly cloudy w/ t-storms

Thursday

75 °F

Turning cloudy, warm; breezy, a thunderstorm around in the afternoon


Thunderstorms

Thursday Night

49 °F

A thunderstorm in spots in the evening; otherwise, considerable cloudiness


Showers

Friday

70 °F

Mostly cloudy with a couple of showers


Thunderstorms

Friday Night

46 °F

Cloudy with showers and thunderstorms


Rain

Saturday

50 °F

Chilly with periods of rain


Rain and snow

Saturday Night

39 °F

Cloudy with rain, mixed with a little snow late


Mostly cloudy

Sunday

59 °F

Mostly cloudy with a stray thundershower in the afternoon


Partly cloudy

Sunday Night

36 °F

Partly cloudy


Sunrise and Sunset

Sunrise
6:08 AM
Sunset
7:49 PM

Based on AccuWeather data