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Reposted by Colorado Climate Center

Russ Schumacher @rschumacher.cloud · 21h

Highly unusual situation approaching western Colorado with the moisture from Hurricane Priscilla. Grand Junction has never had precipitable water over an inch (25mm) so late in the year, but looks like it will be near that level on both Fri & Sat. Six standard deviations above average! #cowx 1/2

Global Ensemble Forecast System mean precipitable water and 700-mb winds valid on Saturday morning, 11 October 2025. A big plume of moisture will be transported into the southwest US ahead of decaying Hurricane Priscilla. From https://schumacher.atmos.colostate.edu/weather/ens.php

Standardized anomaly of precipitable water from the ECWMF ensemble mean on Saturday morning, 11 October 2025. It shows a broad swath of greater than +3 standard deviations in the western US. From https://schumacher.atmos.colostate.edu/weather/ecmwf.php

Ensemble forecast plume showing precipitable water at Grand Junction, Colorado in the members of the ECWMF ensemble. Values are predicted to be around 25-30 mm with high confidence on Friday 10 October through Saturday 11 October, far above the 90th percentile for the date. From https://schumacher.atmos.colostate.edu/weather/ecmwf.php

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Colorado Climate Center @climate.colostate.edu · 1d

And explore the data yourself with these interactive maps: climate.colostate.edu/normals_stn_...

screenshot from https://climate.colostate.edu/normals_stn_select_freeze.html, showing the interactive map of the median date of the first fall freeze across Colorado.

Graph showing the probability of the first date of reaching various temperatures at Rocky Ford, Colorado. The median date of the first temperature 32 or lower is October 8 at this location.

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Colorado Climate Center @climate.colostate.edu · 1d

Most of Colorado's lower elevations haven't yet had a freeze this fall, but it'll get cold sooner or later. Here's our blog post from last year on when first freezes tend to happen across the state. #cowx

First fall freezes - Colorado Climate Blog

Climatological fall has arrived, and although September thus far has been much warmer than normal across most of Colorado, it’s still time to be thinking about when the first freeze could happen. Now,...

climate.colostate.edu

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Colorado Climate Center @climate.colostate.edu · 6d

We hope you'll join us at the CSU Spur Campus in Denver on Oct 14 from 3-5pm! Our team will be talking about Colorado's climate and how it's changing.

This event is free and open to the public, but be sure to register using the link below ⬇️

CSU Department of Atmospheric Science @csuatmossci.bsky.social · 8d

Join our CSU Climate Hub at Spur Launch Event, Oct 14.

1️⃣Get updates on Colorado from the Colorado Climate Center @climate.colostate.edu
2️⃣Brainstorm innovative climate solutions
3️⃣Learn about climate research activities

Register and learn more: events.colostate.edu/en/8XFV416/c...

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Colorado Climate Center @climate.colostate.edu · 7d

TL;DR: water years follow the natural cadence of the water cycle from snowpack buildup to runoff.

So while Oct marks the start to "spooky season" for many of us, your local water managers, hydrologists, and climatologists will be celebrating the "new year" with fresh water supply accounting.🎉[7/7]

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Colorado Climate Center @climate.colostate.edu · 7d

The water year also aligns nicely with patterns in streamflow. It captures the gradual increase in runoff throughout the spring, followed by summertime peak, then the gradual decline in late summer/early fall. [6/7]

A hydrograph showing 7-day average discharge (or streamflow) at a streamgauge site on the Colorado River near Cameo during the water year (Oct-Sep). The lines on the graph generally show gradually increasing streamflow in the spring, peak streamflow in the summer, and then decreasing streamflow in the fall. There is a line for each year of data (1934-2025), and key percentiles are highlighted. POR = period of record (92 years at this site). Data from USGS and NRCS.

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Colorado Climate Center @climate.colostate.edu · 7d

Starting the water year on Oct 1 means we account for most (if not all) of the winter snowpack.

This graph of water year snow water equivalent (SWE) at Fremont Pass shows this well. Look how much water would be unaccounted for during the spring runoff if we only started counting on Jan 1! [5/7]

A graph showing historical snow water equivalent (SWE) from Oct-Sep at Fremont Pass. There are several lines on the graph (such as historical maximum and minimum SWE at that site). All lines generally show increasing SWE from Oct to May, followed by a steep decrease in May-June during the spring melt. Data from NRCS.

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Colorado Climate Center @climate.colostate.edu · 7d

If you're familiar with Colorado, or even the West more generally, you're probably aware that our winter snowpack is the biggest contributor to our warm season water supply.

This snowpack starts to build in the fall (long before the start of the calendar year). [4/7]

View looking towards Emerald Lake in Rocky Mountain National Park in early November 2019. There is deep snow on the ground. Pine trees are scattered across the foreground and there are snow-capped peaks in the background. The sky is mostly clear and sunny.

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Colorado Climate Center @climate.colostate.edu · 7d

But why begin tracking the movement of water in October?

A big reason for offsetting the water year from the calendar year is so that we can properly budget how much winter precipitation will be available for the following runoff season. [3/7]

A river with blocks of snow and ice. There are steep hills with trees on each side of the river, and the sky is partly cloudy.

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Colorado Climate Center @climate.colostate.edu · 7d

A water year is defined as a 12-month period spanning October 1 through September 30th of the following year. As the name implies, water years are used to help track the movement of our water. 📆 [2/7]

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Colorado Climate Center @climate.colostate.edu · 7d

Happy New (Water) Year! 🥳 Today marks the first day of Water Year 2026. But what is a "water year" and why does it begin in October? Here's a short explainer! [1/7]

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Colorado Climate Center @climate.colostate.edu · 13d

Only some of this precipitation was incorporated in this week's U.S. Drought Monitor (the weekly data cutoff is Tuesdays at 6am MDT). Nonetheless, we still saw some drought improvements throughout the state this week! 🌧️

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Colorado Climate Center @climate.colostate.edu · 14d

Yesterday was the wettest day in quite some time for northeastern Colorado. Widespread observations of over 1" of rain, and over 2" in some spots on the Plains.

Several inches of snow in the mountains too!

Map from coagmet.colostate.edu #cowx

Map of precipitation from CoAgMET on September 23, 2025. It shows over 1" of rain across all of northeast Colorado, with a maximum of 2.33" at Akron.

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Colorado Climate Center @climate.colostate.edu · 20d

9/18 Drought Update 🌵: We saw more beneficial precipitation last week, which prompted widespread improvements in western and southern Colorado in this week's US Drought Monitor. Good news for now, but we'll need additional moisture to continue chipping away at those longer-term deficits.

Summary graphic titled "Colorado Drought Update". It shows the current US Drought Monitor for Colorado, change in the current US Drought Monitor for Colorado since last week, and percent area of Colorado experiencing drought.

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Colorado Climate Center @climate.colostate.edu · 28d

August Recap ⏪: Hot, dry conditions intensified drought and fanned wildfires across western Colorado, but monsoon moisture finally delivered some much-needed precipitation at the end of the month. Just how significant was that rainfall? All that and more in our monthly climate summary! col.st/STpEm

A summary flier showing a map of Colorado with the US Drought Monitor overlaid with notable climate statistics August 2025. There is a photo of a waterfall with trees behind the map and text.

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Colorado Climate Center @climate.colostate.edu · Sep 4

Last week's sorely needed rain across western Colorado was enough to remove the D4 (exceptional) drought in the northwest. Still, though, 25% of the state is in D3 (extreme) drought, with very large precipitation deficits going back to the beginning of the year. #cowx climate.colostate.edu/drought/

US Drought Monitor for Colorado on September 2, 2025. It shows all of western Colorado in drought, with widespread D3 (extreme) drought. Eastern Colorado is nearly drought-free.

US Drought Monitor 1-week change map, showing 1-category improvements across parts of Colorado, including the removal of D4 in the northwest part of the state.

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Colorado Climate Center @climate.colostate.edu · Aug 29

“The biggest factor is the dry spring conditions and layered on top of them a much drier than normal summer,” said Peter Goble, assistant state climatologist. “We will be watching those base flows but also soil moisture levels as we go into fall and early winter to see if those pick back up.” #cowx

Low river flows trigger calls, closures, stressed fish - Aspen Journalism

Streamflows on the Western Slope have plummeted over the last month, sending water managers scrambling to boost flows for endangered fish and ranking it among the driest years in recent history.

aspenjournalism.org

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Reposted by Colorado Climate Center

The Colorado Sun ☀️ @coloradosun.com · Aug 27

Monsoonal rains are dousing western Colorado wildfires. They also come with serious flood concerns.

Local officials and weather experts are watching burn scars in Colorado as monsoon rains elevate the risk of debris flows and flash floods.

coloradosun.com

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Reposted by Colorado Climate Center

National Weather Service @nws.noaa.gov · Aug 22

Flash flooding possible today in Georgia and South Carolina. By Monday, chances for heavy rain increase for the southern Plains, and may linger into late in the week. Keep up with the forecast at weather.gov, and remember: Turn Around, Don't Drown when encountering flooded roadways.

Map showing slight risk areas for excessive rainfall.

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Colorado Climate Center @climate.colostate.edu · Aug 20

Greetings from the Colorado Water Congress summer conference in beautiful (but dry) Steamboat Springs. We’re discussing our work with CoAgMET and especially the effort to improve soil moisture monitoring across Colorado!

Photo of a display table with weather instruments and a mountain landscape in the background

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Colorado Climate Center @climate.colostate.edu · Aug 18

Finally, a pattern change on the way for western Colorado! Model forecasts of precipitable water (total water vapor in the atmosphere) at Grand Junction show more hot and dry this week, but then some real moisture next wk. Too early to say how much rain or drought relief, but a welcome sight.🤞 #cowx

Forecast plume of precipitable water at Grand Junction from the ECWMF ensemble prediction system. Each member is in a colored line, the mean in black, and the climatological mean and 10th/90th percentile in dashed gray. PW will be very low for the next few days before steadily increasing this weekend and through next week.

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Reposted by Colorado Climate Center

The Denver Post @denverpost.com · Aug 15

“Northwestern Colorado is the epicenter of drought in the whole country right now,” said Colorado’s state climatologist and the director of the Colorado Climate Center. “It’s about as bad as it gets.”

Western Colorado is at the ‘epicenter of drought’ as a hot, dry summer saps water supplies — and fuels wildfires

“If we have another year like this next year and Wolford (Mountain Reservoir) gets drawn down farther, then we’re in a precarious spot.”

trib.al

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Colorado Climate Center @climate.colostate.edu · Aug 15

ICYMI: Parts of western Colorado are now experiencing exceptional drought. Curious how we got here and what we might expect in the coming weeks and months? Check out today's blog post ⬇️

col.st/j3EpX

Mid-August Colorado drought update: exceptional drought returns to the state for the first time since 2023 - Colorado Climate Blog

The latest US Drought Monitor (released August 14) highlights big changes to the current drought situation in western Colorado, including the introduction of “exceptional” or “D4” conditions to some l...

col.st

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Colorado Climate Center @climate.colostate.edu · Aug 14

*minor correction, there was a small bit of D4 in Colorado into May 2023

Reposted by Colorado Climate Center

National Weather Service @nws.noaa.gov · Aug 14

Info for Utah, Idaho, Wyoming, Colorado, and Nevada 👇
"Dry thunderstorms will be the primary fire weather concern for today across the northeastern Great Basin, though warm, dry, and windy conditions will likely develop across parts of the Great Basin and northern Rockies." - NWS Forecast Discussion

Fire Weather Outlook
Thursday, August 14, 2025
Map of the Rockies and western U.S. showing the Critical Fire Weather Conditions and risk for scattered dry thunderstorms across Nevada, Utah, Colorado, Wyoming, Idaho, and southern Montana.

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