Skip to content

The Front Range Forecast: Thunderstorms, Heavy Rain

In Brief:

Severe weather to our east Thursday, storms and prolonged rain for the weekend.

The Forecast Discussion:

We have one more warm day, Thursday, with moisture streaming into the state. We might see thunderstorms form in the foothills in the early afternoon (Figure 1).  As they move east, they will tap into much deeper moisture and instability. With an approaching upper air low, (to the upper left of the state a day later in Figure 4) they will have the potential to become severe storms just east of I-25 (Figure 2). These storms may even produce isolated tornadoes out on the lains (Figure 3). The weekend will be covered in the Longer Range Forecast below.

figure1_04252024
Figure 1: the 10 day graphical forecast for Longmont from weatherunderground.com
figure2_04252024
Figure 2: the day 1 severe weather forecast map from the SPC.
figure3_04252024
Figure 2: the day 1 tornado risk forecast map from the SPC.

The Longer Range Forecast:

Another, deeper, trough will approach the state for the weekend and cut-off, slowing a lot (Figure 4). It looks like healthy rain rates and snow in the mountain will remain in place from Friday afternoon through Sunday morning (Figure 1 and 5).

Weatherunderground (Figure 1) gives Longmont about 2 inches of liquid. The GFS (Figure 6) is much more bullish. It has a bullseye of 3.5+ rain from central Larimer County to Boulder County. Much of central and northeast Colorado gets 1-2 inches.

Figure 7 shows snowfall.  It is very elevation dependent, picking up rapidly as you climb into the mountains (that is a strong cut-off line!). Places in RMNP may see a foot or two of snow while Estes Park only picks up a few slushy inches. Allenspark might see a foot or more.

We warm up again next week with thunderstorms returning mid-late week.

figure4_04252024
Figure 4: the 500mb upper air forecast map for Saturday evening from the GFS and tropicaltidbits.com
figure5_04252024
Figure 5: the surface precipitation and pressure forecast map for Saturday evening from the GFS and tropicaltidbits.com
figure6_04252024
Figure 6: the 5 day precipitation forecast from the GFS and weather5280.com
figure7_04252024
Figure 7: the 5 day 10:1 snowfall ratio 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.
Read more


Comments


Current Weather

Mostly sunny

Mostly sunny

60°F

UV Index
1 Low
Pressure
29.76 Falling
Visibility
3 miles
Dewpoint
57 °F
Humidity
91%
Wind
SW 1.1 mph
Gust
2.3 mph
Wind Chill
60 °F

Hourly Forecast

Today
7 AM
61°F
Cloudy
Today
8 AM
69°F
Mostly sunny
Today
9 AM
76°F
Mostly sunny
Today
10 AM
81°F
Mostly sunny
Today
11 AM
85°F
Partly sunny
Today
12 PM
88°F
Intermittent clouds
Today
1 PM
90°F
Intermittent clouds
Today
2 PM
92°F
Intermittent clouds
Today
3 PM
90°F
Intermittent clouds
Today
4 PM
88°F
Mostly cloudy w/ t-storms
Today
5 PM
85°F
Intermittent clouds
Today
6 PM
84°F
Intermittent clouds

7 Day Forecast

Partly sunny w/ t-storms

Saturday

92 °F

Warmer with intervals of clouds and sunshine; a thunderstorm around this afternoon


Mostly clear

Saturday Night

57 °F

Clear to partly cloudy


Mostly sunny

Sunday

93 °F

Sunny to partly cloudy and very warm


Partly cloudy

Sunday Night

56 °F

Partly cloudy


Partly sunny

Monday

94 °F

Partly sunny and hot; breezy in the afternoon


Clear

Monday Night

55 °F

Windy in the evening; clear


Partly sunny

Tuesday

80 °F

Partly sunny and cooler; breezy in the afternoon with a thundershower in spots


Mostly cloudy

Tuesday Night

52 °F

Mostly cloudy with a shower in the area late


Cloudy

Wednesday

75 °F

A thunderstorm around in the morning; otherwise, cloudy


Intermittent clouds

Wednesday Night

55 °F

Partly cloudy with a stray thunderstorm late


Sunrise and Sunset

Sunrise
5:30 AM
Sunset
8:32 PM

Based on AccuWeather data