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Thursday Update: Longmont Weather Forecast: Dry weather turns cool and wet Saturday afternoon

In Brief:

Two last days of warm and dry weather followed by five days of cooler, damp weather.

Thursday Update:

We have another couple of days of nice weather before afternoon thunderstorms Saturday usher in a two day, rainy, cool spell (Figure 1 update).  Already, a chance of severe weather returns to areas along I-25 south of Longmont (Figure 2 update).  Later next week, warmer 80's arrive with dry weather again! You should probably plan indoor activities for Sunday and Memorial Day.

 

Figure1u_05272021Figure 1 update: the 10 day graphical forecast for Longmont CO from weatherunderground.com

 

Figure2u_05272021Figure 2: the Day 3 (Saturday) convection/severe weather forecast from the SPC.

 

End Thursday forecast.

Forecast Discussion:

A ridge is back suppressing thunderstorms and warming us up (Figure 1). Through Saturday morning, we will see only a rare afternoon thunderstorm form in the mountains and move off to the east (Figure 2). It will be fantastic out there. Just enough moisture returns on Wednesday that we will see a few more thunderstorms around Longmont, and a Marginal Risk of severe weather just to the northeast.  Thunderstorms will be widely scattered (Figure 3).

 

Figure1_05242021Figure 1: the 500 mb forecast map from the GFS for Tuesday noon from tropicaltidbits.com

 

Figure2_05242021Figure 2: the 10 day graphical forecast for Longmont, CO from weatherunderground.com

 

Figure3_05242021Figure 3: the SPC storm forecast map for Day 3/Wednesday.

The Longer-Range Forecast:

Our next trough begins to impact the weather on Saturday as it approaches from the west (Figure 4).  Temperatures drop a bit into next week with a better chance of rain each day (Figure 2). The GFS keeps us dry for the next five days, then gives the plains some good moisture again in the following days (Figure 5).

Figure4_05242021Figure 4: the 500 mb forecast map from the GFS for Sunday noon from tropicaltidbits.com

 

 

 

Figure5_05242021Figure 5: the 10 day precipitation forecast from the GFS and weather5280.com

 


About the Author: John Ensworth

John Ensworth used to work from Longmont as the PI for the NASA through the IGES (The Institute for Global Environmental Strategies). He now teaches technology, algebra, astronomy, meteorology, film school, and Lego robotics to middle/high school.
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Current Weather

Mostly clear

Mostly clear

71°F

UV Index
0 Low
Pressure
30.06 Steady
Visibility
8 miles
Dewpoint
53 °F
Humidity
53%
Wind
N 1.8 mph
Gust
3.5 mph
Wind Chill
71 °F

Hourly Forecast

Tomorrow
12 AM
71°F
Mostly clear
Tomorrow
1 AM
68°F
Mostly clear
Tomorrow
2 AM
66°F
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Tomorrow
3 AM
65°F
Mostly clear
Tomorrow
4 AM
64°F
Mostly clear
Tomorrow
5 AM
63°F
Mostly clear
Tomorrow
6 AM
62°F
Mostly sunny
Tomorrow
7 AM
62°F
Partly sunny
Tomorrow
8 AM
65°F
Intermittent clouds
Tomorrow
9 AM
68°F
Intermittent clouds
Tomorrow
10 AM
72°F
Intermittent clouds
Tomorrow
11 AM
75°F
Intermittent clouds

7 Day Forecast

Intermittent clouds

Tuesday

94 °F

Very warm with intervals of clouds and sunshine


Partly cloudy

Tuesday Night

62 °F

Partly cloudy


Partly sunny w/ t-storms

Wednesday

82 °F

Not as warm with times of sun and clouds; an afternoon thunderstorm; thunderstorms can bring hail and damaging winds


Partly cloudy w/ t-storms

Wednesday Night

60 °F

An evening thunderstorm; otherwise, partly cloudy


Thunderstorms

Thursday

86 °F

Mostly cloudy with a thunderstorm in spots in the afternoon


Partly cloudy

Thursday Night

58 °F

Partly cloudy


Mostly cloudy

Friday

91 °F

Variable cloudiness


Mostly clear

Friday Night

58 °F

Clear to partly cloudy


Partly sunny

Saturday

88 °F

Partly sunny with a thunderstorm in spots in the afternoon


Clear

Saturday Night

60 °F

Clear


Sunrise and Sunset

Sunrise
5:44 AM
Sunset
8:29 PM

Based on AccuWeather data