u/BoulderCAST — reddlx

NOTE: This post will be updated leading up to and during the event.

UPDATE (Tue May 5 2026 8AM): Snow totals bumped up a tad

No major changes are needed to the forecast this morning, other than bumping up totals by a couple inches in most locations due to higher confidence that heavy wet snow will fall most of Tuesday night and all of Wednesday morning. This magnitude of snow will bring significant tree and power line damage from this event. We recommend shaking off your trees periodically and parking cars away from trees. A hard freeze will occur Wednesday night (temps 23 to 28°) so drain above ground pipes, disconnect hoses and protect your plants!

Update Snow Forecast Amounts:

Foothills and Mountains: 12-28 inches, locally up to 30 inches on the high peaks just east of the Divide. Highest from Nederland north through Estes Park. Lower totals of 7-15 inches along/south of I-70 area.
Boulder: 7-13" inches, most of this coming Tuesday 6PM to Wednesday at Noon.
Most of Denver area: 4-8 inches. Highest 5500+ feet.

NEW SNOW MAP

UPDATED FORECAST DISCUSSION

Everything else remains on-track with our post from yesterday below. Let's hope this moisture does wonders for our vegetation and animals which have been suffering. Happy Snow and Namaste!

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Original Post (Mon May 4 2026 @ 11AM)

After another warm spring weekend, the Front Range is about to get slammed back into winter. A surprisingly potent May storm is lining up for Colorado, and this one checks every box: deep Pacific moisture, prolonged upslope, and a perfectly timed blast of cold air. The result? A high‑impact, late‑season snowstorm with big moisture totals and a real risk of tree damage and power outages.

Some spotty rain or storms arrive Monday evening, but the main event hits Tuesday into Wednesday. Snow levels crash from 7,500 feet Tuesday morning to below 5,000 feet by evening, setting the stage for 18 to 24+ hours of wet, heavy snow across Boulder County.

The real danger comes Tuesday night, when the sun goes down and all the storm ingredients overlap. Intermittent snowfall rates of 1–2"/hour will stick efficiently to fully leafed‑out trees, and widespread limb breakage and outages are likely...potentially worse than the May 2022 storm that knocked out power for 100,000+ Denver area residents, many of which were here in Boulder as we received 8 inches of snow.

Travel impacts will be most noticeable in town Tuesday night into Wednesday morning, especially in areas that pick up more than 5" of slushy accumulation.

Timeline Summary:

Monday: Highs in lower 70s with scattered late-day t-showers
Monday Night: Cold front arrives, cloud base lowers in the early morning, light rain begins
Tuesday: Rain changes to wet snow. Only minor accumulations on the grass until evening. All snow in the Foothills with accumulation starting earlier. Still just wet roads.
Tuesday night: Snow continues everywhere, heavy at times, with embedded pockets over 1" per hour rates. Most of the accumulation will occur from 6PM Tuesday through 9AM Wednesday when the May sun is down or low in the sky. Low temps in the upper 20s to 30° (sub freezing!).
Wednesday: Snow continues all morning, heavy at times, ending sometime during the afternoon or evening. Any slush/snow melts off the roadways during the day despite falling snow.
Wednesday night: Skies become partly cloudy and temps drop below freezing again. 26-30° seems most likely.
Rest of week: Pretty nice, back to the 70s by Friday.

Snow Amounts:

Foothills and Mountains: 1-2 feet, locally up to 30 inches on the high peaks just east of the Divide. Lower totals of 5-12 inches along/south of I-70 area.
Boulder: 5-10 inches (may be too conservative)
Most of Denver area: 2-7 inches, though quite uncertain. Highest 5500+ feet.

A hard-ish freeze will occur as well, with lows in the upper 20s Tuesday night and possibly colder Wednesday night if skies clear. Protect sensitive plants and drain any exposed pipes.

Beneficial Moisture Totals:

1 to 2 inches across Boulder and Larimer Counties. Perhaps a few lucky 2.5" spots.
0.70 to 1.5" in Denver.

Ultimately, Mother Nature is giving us a rare opportunity for drought relief, but unfortunately it comes gift-wrapped inside a high‑impact, damaging snowstorm, one that will leave a mark on both our reservoirs and our trees. We'll take it, though!

Finally some historical context ....

Boulder’s largest May snowstorms:

23.0″ – May 5-6, 1978
12.3″ – May 1-2, 2013
8.7″ – May 25, 1950
8.3″ – May 20-21, 2022
6.8″ – May 11-12, 2014

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Our full forecast discussion can be found here (spoiler it's very long, sorry): https://bouldercast.com/colorado-winter-weather-update-a-significant-snowstorm-is-finally-taking-aim-on-the-front-range-in-may/