https://www.boulderweather.com/tags/afternoon-thunderstorms/Recent content in Afternoon Thunderstorms on BoulderWeather.comHugo -- gohugo.ioenBoulderweather.comTue, 04 Aug 2026 00:00:00 +0000https://www.boulderweather.com/post/boulder-monsoon-season/Tue, 04 Aug 2026 00:00:00 +0000https://www.boulderweather.com/post/boulder-monsoon-season/ <h2 id="the-big-thompson-flood-and-the-storm-pattern-that-returns-every-summer">The Big Thompson Flood and the Storm Pattern That Returns Every Summer</h2> <p>On July 31, 1976, heavy rain began falling over the Big Thompson Canyon near Estes Park during the evening hours, and it kept falling for several hours over the same drainage. An estimated 2,500 people were in the canyon at the time. Rainfall totals of 6 to 10 inches, with localized amounts up to 12 inches, fell between the evening of July 31 and August 2 — enough to push the Big Thompson River to a flood stage of 19.7 feet at the canyon mouth before the gauge measuring it was destroyed by the water, according to the <a href="https://storymaps.arcgis.com/stories/f50f8e71282f4f8f9f2ed2420511e0b6">National Weather Service Denver/Boulder office's 50th-anniversary review of the event</a>. It remains the reference point Front Range forecasters reach for when they need to describe what an extreme summer thunderstorm can do when it parks over steep terrain.</p>