2025-12-20T00:00:00-07:00
...THIS IS A PARTICULARLY DANGEROUS SITUATION FOR IN AND IMMEDIATELY ADJACENT TO THE FOOTHILLS, BETWEEN 5500 AND 9000 FEET, FOR BOULDER AND JEFFERSON COUNTIES ON FRIDAY... Strong west winds, sustained 45-55 mph with gusts upwards of 85-105 mph, are expected in the foothills of Boulder and Jefferson Counties beginning early Friday morning. Relative humidity values are expected to drop into the low teens, possibly upper single digits. While Red Flag conditions, critical fire weather, are expected across a larger area in northern Colorado, the most extreme conditions are expected to be along Highway 93 from Jefferson County into Boulder County and along US-36 north of Boulder to the Larimer County line and westward. There will be a high potential for fast moving wildfires, should any new starts occur. Winds toward I-25 and eastward will be slower to develop, and also speeds will be considerably lighter. That said, gusts of 25-40 mph are still expected to combine with very low humidity and cured grasses to support critical fire weather conditions. Areas farther east into eastern Adams, Arapahoe, Elbert, and Lincoln counties have more uncertainty if those winds even develop, so those locations remain under a Fire Weather Watch. Such conditions may be a longer duration than usual, with potential for low humidity to extend well into the evening hours. * AFFECTED AREA...Fire Weather Zones 238, 240, 241 and 243. * TIMING...From 10 AM Friday to midnight MST Friday night. * WINDS...West 15 to 25 mph with gusts up to 60 mph possible west of I-25, and gusts to 40 mph possible along and east of I-25. * RELATIVE HUMIDITY...As low as 12 percent. * IMPACTS...Conditions will be favorable for rapid fire spread. Avoid outdoor burning and any activity that may produce a spark and start a wildfire.
Summary
Total streamflow across the
Powder River
was last observed at
341
cfs, and is expected to yield approximately
676
acre-ft of water today; about 64%
of normal.
River levels are low and may signify a drought.
Average streamflow for this time of year is
534 cfs,
with recent peaks last observed
on
2011-05-22 when daily discharge volume was observed at
25,478 cfs.
Maximum discharge along the river is currently at the
Powder River At Arvada
reporting a streamflow rate of 243 cfs.
However, the streamgauge with the highest stage along the river is the
Powder River At Moorhead Mt
with a gauge stage of 3.1 ft.
This river is monitored from 4 different streamgauging stations along the Powder River, the highest being situated at an altitude of 4,367 ft, the
Powder River At Sussex.
River Details
| Last Updated | 2025-12-01 |
| Discharge Volume | 676 ACRE-FT |
| Streamflow |
341.0 cfs
-178.7 cfs (-34.39%) |
| Percent of Normal | 63.91% |
| Maximum |
25,478.0 cfs
2011-05-22 |
| Seasonal Avg | 534 cfs |
River Streamflow Levels
| Streamgauge | Streamflow | Gauge Stage | 24hr Change (%) | % Normal | Minimum (cfs) | Maximum (cfs) | Air Temp | Elevation |
|---|---|---|---|---|---|---|---|---|
|
Powder River At Sussex
USGS 06313500 |
144 cfs | 2.82 ft | ||||||
|
Powder River At Arvada
USGS 06317000 |
243 cfs | 2.2 ft | -3.57 | |||||
|
Powder River At Moorhead Mt
USGS 06324500 |
60 cfs | 3.1 ft | 14.02 | |||||
|
Powder River Near Locate Mt
USGS 06326500 |
231 cfs | 1.85 ft | -46.4 |
Seasonal Discharge Comparison
Maximum Streamflow Discharge
Streamflow Elevation Profile
The Powder River Basin is a geologic structural basin in southeast Montana and northeast Wyoming, about 120 miles (190 km) east to west and 200 miles (320 km) north to south, known for its coal deposits. The region supplies about 40 percent of coal in the United States. It is both a topographic drainage and geologic structural basin. The basin is so named because it is drained by the Powder River, although it is also drained in part by the Cheyenne River, Tongue River, Bighorn River, Little Missouri River, Platte River, and their tributaries.
While the Powder River Basin is unified geologically, residents of areas distant from the Powder River proper do not think of themselves as living in a single geographic region. For example, residents of the Crow Reservation in the Big Horn River watershed, or of Sheridan in the Tongue River watershed, would locate the Powder River Basin as the region east of the Big Horn Mountains, using a definition based on watershed and topography.
Major cities in the area include Gillette and Sheridan, Wyoming and Miles City, Montana. Outside of these main towns, the area is very sparsely populated and is known for its rolling grasslands and semiarid climate. The former hunting grounds of the Oglala Lakota, it has become the single largest source of coal mined in the United States, and contains one of the largest deposits of coal in the world. Most of the active coal mining in the Powder River Basin actually takes place in drainages of the Cheyenne River. Because of the Powder River Basin, Wyoming has been the top coal-producing state in the United States since 1988. In 2007, the Powder River Basin alone produced 436 million short tons (396 million tonnes) of coal, more than twice the production of second-place West Virginia, and more than the entire Appalachian region. The Powder River Basin is the largest coal-producing region in the United States. The Black Thunder Coal Mine is one of the most productive coal mines in the United States; in 2006 this single mine produced 84 million metric tons of coal, more than any state except Wyoming, West Virginia, and Kentucky. The region is also a major producer of natural gas, both conventional natural gas and coal-bed methane.