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The Next Storm/Next Snow Forecast Discussion from the Cherrywood Observatory – September 30, 2017

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

Forecast Discussion:

Being on vacation this week, I'm going to keep these just a bit briefer than normal... Figure 1 shows the trough pulling up into the ridge, That ridge has already slided east of the state in this progressive pattern.  This will kick off a chance of rain and higher mountain snows Saturday and Saturday PM.  The big picture is that the jet stream is going to park in the vicinity of our state for many days now. Every ripple that travels downstream can kick off another round of showers across the state.

Figure 1: The Thursday night 500mb upper air map.

In the longer range:

Figure 2, for example, shows another trough moving in on Monday morning, digging cooler air and lift pretty far south. Figure 3 is the 10 day -at a glance- with the greater chance of significant rain for Monday in Longmont. Achance of daily showers - and cool temperatures -  is the story for days to come.  Now I'm off to an out-of-state family wedding!

Figure 2: The GFS forecast 500mb upper air map for Monday morning.

Figure 3: The weatherunderground 10 day graphical forecast.

Current Weather

Mostly cloudy

Mostly cloudy

58°F

UV Index
6 High
Pressure
29.6 Falling
Visibility
8 miles
Dewpoint
23 °F
Humidity
26%
Wind
WSW 10 mph
Gust
22.2 mph
Wind Chill
58 °F

Hourly Forecast

Today
12 PM
58°F
Mostly cloudy w/ showers
Today
1 PM
59°F
Mostly cloudy
Today
2 PM
60°F
Intermittent clouds
Today
3 PM
62°F
Intermittent clouds
Today
4 PM
60°F
Intermittent clouds
Today
5 PM
58°F
Intermittent clouds
Today
6 PM
56°F
Intermittent clouds
Today
7 PM
54°F
Intermittent clouds
Today
8 PM
51°F
Intermittent clouds
Today
9 PM
48°F
Partly cloudy
Today
10 PM
45°F
Partly cloudy
Today
11 PM
43°F
Partly cloudy

7 Day Forecast

Partly sunny w/ showers

Tuesday

62 °F

A couple of brief showers late this morning; windy with times of clouds and sun


Partly cloudy

Tuesday Night

34 °F

Partly cloudy and colder; there can be frost in the normally colder spots


Intermittent clouds

Wednesday

59 °F

Cool with times of clouds and sun


Mostly cloudy w/ showers

Wednesday Night

37 °F

Increasing clouds with a shower in spots late


Partly sunny w/ showers

Thursday

56 °F

Times of clouds and sun with a couple of showers; cool


Partly cloudy

Thursday Night

40 °F

Partly cloudy


Mostly cloudy

Friday

63 °F

Mostly cloudy and warmer


Clear

Friday Night

40 °F

Clear


Mostly sunny

Saturday

74 °F

Mostly sunny, pleasant and warmer


Mostly clear

Saturday Night

43 °F

Mainly clear


Sunrise and Sunset

Sunrise
5:52 AM
Sunset
8:02 PM

Based on AccuWeather data