Category: Tropical Weather (Page 1 of 22)

September 2026 Weather Review: Extreme Drought Rolls On Alongside Boulder’s 17th Consecutive Warmer Than Normal Month

October 7, 2026 / BoulderCAST Team / 0 Comments

September 2026 will be remembered as the month that put an exclamation point on an extraordinary water year of heat and dryness in Boulder, with less than 20% of normal precipitation falling during the month and temperatures more than five degrees above average. Despite a strong late-season monsoon, moisture largely avoided the Front Range, and especially Boulder County, culminating with a great modeling collapse of a significant rain event in the final days of the month tied to the remnants of Hurricane Polo.

Here’s a graphical look at how September 2026 unfolded across Boulder, Denver, and the Front Range — and how it compared to climatology.

Hydrologic Failure — How Every Season Conspired to Produce Boulder’s Driest Water Year on Record

October 6, 2026 / Ben Castellani / 0 Comments

Boulder just endured its driest water year on record, closing out twelve months with only 10.65 inches of precipitation — barely half of normal and nearly at desert-level. From a failed snow season to record spring warmth and a monsoon that largely bypassed the city, every season conspired to keep Boulder locked in a warm‑and‑dry feedback loop. Reservoirs and upstream snow storage will cushion the blow for now, but the bigger question looms: what happens if we start stringing years like this together?

Premium Storm Update – Wed 09/30/26 7:30AM | A Near‑Miss Yet Again as Soaking Storm System Only Grazes the Denver Area Today

September 30, 2026 / Ben Castellani / 2 Comments

A slow‑moving, high‑stakes storm has been creeping toward Colorado all week — a rare mash‑up of an autumn upper‑low and the juicy tropical remnants of Hurricane Polo — and for a moment, it looked like Boulder and Denver might finally score a true soaking. But as the atmosphere loves to do, the script flipped late. Today’s update breaks down how this once‑promising setup unraveled over the last couple days, why southern Colorado is now squarely in the bullseye, and what scraps of moisture the Front Range can still squeeze out as the system passes by to our south.

A Soaker or a Near‑Miss: Will Hurricane Polo’s Remnants Push Far Enough North to Drench Denver and Boulder? (Updated)

September 29, 2026 / BoulderCAST Team / 0 Comments

A slow‑building, tropical‑charged system is about to make its move on Colorado — and the setup behind it is far more complex than your typical late‑September storm. As Hurricane Polo’s remnants collide with a impressive Pacific upper‑low, the stage is set for a rare, moisture‑laden system that could deliver anything from a major rain event to a near‑miss for Boulder and Denver. We break down why the models are struggling, what the key track differences mean for your neighborhood, and where flooding and high‑elevation snow may become real concerns as the storm unfolds.

UPDATED Tuesday Sep 26 5:00PM: Updated rainfall forecast map and some wording to account for growing confidence the bulk of the storm will miss the Denver Metro area.

This Week in Colorado Weather: September 28, 2026

September 28, 2026 / Andy / 0 Comments

A complicated weather pattern is taking shape across Colorado this week, with a deep low pressure system, a surge of tropical moisture, and the remnants of Hurricane Polo all getting tangled up together. For Boulder, Denver and the Front Range, that combination creates some unusually large forecast uncertainties — particularly when it comes to how much rain falls and just how chilly things get by midweek. Meanwhile, southern Colorado is in store for a much bigger soaking, with some impressive rainfall totals showing up in the guidance alongside high peak snowfall. We break down what we know now, what remains uncertain, and when we can finally expect this week’s definitively gloomy weather to break and sunshine to return.

Colorado Forecast Update: Thursday Gloom, a Beautiful Weekend and Some Big, Wet Questions for Next Week

September 24, 2026 / BoulderCAST Team / 0 Comments

The pattern is gradually shifting across Colorado, with lingering moisture keeping Thursday cool and cloudy before drier, warmer weather settles in for the weekend. Beyond that, the forecast becomes much less certain as the first significant autumn trough approaches from the west and potentially interacts with the remnants of Hurricane Polo across the southern Rockies. There are several possible outcomes for early next week in the Front Range, ranging from a quick cooldown with some showers to a much wetter setup. We break down what the models are showing, what we’re confident in, and what remains uncertain.

This Week in Colorado Weather: September 21, 2026

September 21, 2026 / Ben Castellani / 0 Comments

Despite an active monsoon that refuses to quit, Boulder has remained stubbornly dry with just 18% of normal precipitation during September which has been anything but typical. This week will keep the theme alive: plenty of monsoon flow, impressive moisture surges, and even a pair of dancing hurricanes in the Eastern Pacific, yet northern Colorado will still struggle to squeeze out meaningful rainfall again. We break down why the pattern looks so active on paper, why the Front Range keeps missing out, and what late‑week changes might finally nudge storm chances upward.