Skip to content

The Next Storm/Next Snow Forecast Discussion from the Cherrywood Observatory – September 1, 2017

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

Forecast Discussion:

The forecast of the last few days is still right on track. Things were quiet Thursday night, but clouds were increasing and a few showers were wandering around the state. There were more up near the Wyoming border.  Showers are expected across Colorado into the early hours of morning (Figure 1) before the trough, pushing the cool front along, passes and we get sinking air behind it shutting off the rain chances early Friday (see Figure 2).

Figure 1: The NCEP forecasted surface analysis map showing chances of rain Friday before dawn.

Figure 2: The forecasted 500mb pattern from the GFS model for this morning (Fri. AM).

In the longer range:

The ridge is back with a vengeance by Saturday afternoon and really getting strong on Sunday (Figure 3). The high center is right over Northern Colorado. We very well might break the record high of 95F for the date. The good news is the trough over the Great Lakes in the eastern U.S. deepens and the ridge retrogrades westward giving us a flow of Canadian air down the Plains by Tuesday and Wednesday next week (Figure 4).  We may even get a bit of cooling on Monday from this change. Figure 5 shows the 24 hour precipitation accumulation Monday into Tuesday next week.  The remains of both tropical systems Lidia and Harvey are still barely on the map (Harvey's remains are just exiting Maine at that time). There some precipitation over northern Colorado, but more rain over southern Colorado at the end of the Labor Day Holiday Weekend.

Figure 3: The Sunday morning forecasted 500mb pattern from the GFS model.

Figure 4: Tuesday 500mb forecast map from the GFS. LIght blue line shows cooler airflow.

Current Weather

Mostly cloudy

Mostly cloudy

38°F

UV Index
0 Low
Pressure
30.21 Rising
Visibility
8 miles
Dewpoint
30 °F
Humidity
73%
Wind
ENE 3.1 mph
Gust
6.9 mph
Wind Chill
36 °F

Hourly Forecast

Today
1 AM
40°F
Partly cloudy
Today
2 AM
39°F
Partly cloudy w/ showers
Today
3 AM
39°F
Partly cloudy w/ showers
Today
4 AM
38°F
Partly cloudy
Today
5 AM
38°F
Partly cloudy
Today
6 AM
37°F
Partly sunny
Today
7 AM
39°F
Partly sunny
Today
8 AM
43°F
Partly sunny
Today
9 AM
46°F
Partly sunny
Today
10 AM
50°F
Partly sunny
Today
11 AM
53°F
Partly sunny
Today
12 PM
56°F
Partly sunny

7 Day Forecast

Mostly cloudy w/ showers

Friday

76 °F

Some sun, then increasing clouds, becoming breezy this afternoon with a shower in spots late in the afternoon


Partly cloudy w/ showers

Friday Night

37 °F

Partly cloudy with a couple of showers


Partly sunny

Saturday

66 °F

Not as warm with sun and some clouds


Mostly clear

Saturday Night

39 °F

Clear to partly cloudy


Mostly cloudy

Sunday

76 °F

Mostly cloudy and warmer; breezy in the afternoon


Mostly cloudy

Sunday Night

51 °F

Rather cloudy; windy late


Windy

Monday

60 °F

Winds gusting past 40 mph; cloudy and cooler


Intermittent clouds

Monday Night

43 °F

Breezy in the evening; otherwise, partly cloudy


Intermittent clouds

Tuesday

62 °F

Times of clouds and sun; windy in the afternoon


Intermittent clouds

Tuesday Night

36 °F

Clearing


Sunrise and Sunset

Sunrise
5:57 AM
Sunset
7:58 PM

Based on AccuWeather data