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The Next Storm/Next Snow Forecast Discussion from the Cherrywood Observatory – September 20th, 2018

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

Forecast Discussion:

The moisture is here (Figure 1)! For Loveland, Ft. Collins, and Denver - it came in with a bang (thunderstorms). Longmont saw light showers.

We can track the waves of arriving cold air by looking at my outline of the advancing cold air (thin black lines between blue and orange regions) in Figures 2 to 4. At noon on Wednesday, the cold air was just nosing down towards Ft. Morgan (Figure 2). By tonight the first blob of cool is sinking into Mexico while the next hit is on its way for Friday (Figure 3). For noon on Friday the next wave of colder air is past and things are pretty windy (Figure 4).

The total rainfall through Friday noon still is only a few hundredths of an inch of rain to maybe a one or two tenths (Figure 5).

Figure 1: the water vapor satellite image from Wednesday afternoon. Reds/Oranges are dry air, greys/whites are moist air regions.

Figure 2: The surface temperature anomaly (departure from normal) for Wednesday noon (yesterday).

Figure 3: The surface temperature anomaly (departure from normal) for Thursday PM.

Figure 4: The surface temperature anomaly (departure from normal) for Friday noon.

Figure 5: The total precipitation between Wednesday PM and Friday midday from the GFS and weather5280.com

The longer range forecast:

That cool air slides out for the weekend and we briefly return to upper 80's F for your time by the pool. Next week we drop to 70's F and eventually 60's F later in the week. There are some rain chances next week. We should see lows drop to the upper 30's F later in the week. More on that later!

Current Weather

Sunny

Sunny

42°F

UV Index
1 Low
Pressure
30 Rising
Visibility
9 miles
Dewpoint
24 °F
Humidity
49%
Wind
SSW 2.7 mph
Gust
6 mph
Wind Chill
41 °F

Hourly Forecast

Today
8 AM
43°F
Mostly sunny
Today
9 AM
47°F
Mostly sunny
Today
10 AM
51°F
Mostly sunny
Today
11 AM
55°F
Mostly sunny
Today
12 PM
58°F
Mostly sunny
Today
1 PM
60°F
Partly sunny
Today
2 PM
62°F
Intermittent clouds
Today
3 PM
63°F
Mostly cloudy
Today
4 PM
64°F
Mostly cloudy
Today
5 PM
63°F
Cloudy
Today
6 PM
61°F
Cloudy
Today
7 PM
58°F
Mostly cloudy

7 Day Forecast

Intermittent clouds

Thursday

64 °F

A blend of sun and clouds; breezy this afternoon


Mostly cloudy

Thursday Night

35 °F

Mostly cloudy


Partly sunny

Friday

68 °F

Increasingly windy with partial sunshine


Partly cloudy

Friday Night

38 °F

Partly cloudy


Partly sunny

Saturday

66 °F

Partial sunshine


Mostly clear

Saturday Night

41 °F

Clear to partly cloudy


Mostly cloudy

Sunday

78 °F

Rather cloudy and warmer; windy in the afternoon


Intermittent clouds

Sunday Night

43 °F

Partly cloudy; windy late


Mostly cloudy

Monday

60 °F

Mostly cloudy, breezy and cooler


Mostly cloudy

Monday Night

43 °F

Mostly cloudy


Sunrise and Sunset

Sunrise
5:58 AM
Sunset
7:57 PM

Based on AccuWeather data