Western US Daily Snow
By Alan Smith, Meteorologist Posted 8 hours ago June 17, 2025
Heating Up Southwest, Cooler & Wetter Outlook Northwest
Summary
The severe weather threat will decrease across Montana & Wyoming this week after several active days. A heatwave will take hold over the Southwest & Colorado with temps hitting triple digits in lower elevation terrain. A cooler pattern will take hold across the Northwest this week with the potential for significant rainfall on Friday-Saturday, with high-elevation snow also possible.
Short Term Forecast
Helpful Links:
Monday Afternoon Update:
The past several days have featured strong to severe thunderstorms across portions of Montana and Wyoming, and Monday has been no exception.
Check out our Lightning Risk Map as of 4 PM on Monday:
The severe weather threat will decrease across Montana and Wyoming later this week, as attention turns to a colder and wetter system that will push into the Northwest toward the end of the week.
5-Day Temperature Outlook (June 17-21):
A heatwave will take hold over the Southwest and the Southern Rockies this week, with lower elevation cities such as Albuquerque, Denver, and Salt Lake City flirting with 100 degrees.
It will be a different story in the Northwest as a trough-dominant pattern takes hold with temperatures running below normal across Washington, Oregon, and Northern California.
Tuesday (June 17):
Before Colorado really heats up later this week, a cold front will slide down the eastern side of the Continental Divide on Tuesday morning, and easterly winds behind the front will usher in moisture, supporting a more active thunderstorm day compared to prior days.
Areas along and east of the Continental Divide throughout Colorado, Wyoming, and Southern Montana can expect active weather on Tuesday with showers and thunderstorms possible during the morning, giving way to more numerous and stronger thunderstorms in the afternoon.
The Front Range foothills and adjacent plains in Colorado and Southeast Wyoming have a risk of severe thunderstorms on Tuesday afternoon, with large hail being the primary threat. Instability and wind shear will be maximized in this region as a shortwave trough moves through.
The risk of severe weather will not be quite as high in Central/Northern Wyoming and Southern Montana due to less instability, but isolated strong to severe storms will still be possible with an outside chance of large hail.
Areas immediately west of the Divide could potentially see some isolated thunderstorms, but coverage and intensity will be less compared to east of the Divide.
Wednesday (June 18):
Much drier air will push into the Rockies, and a thunderstorm-free day is expected along with warmer temperatures.
Over the Northwest, a cold front will move through with an uptick in moisture behind the front, leading to light rain showers mainly west of the Cascades Crest.
Thursday (June 19):
Wednesday's frontal system will weaken significantly as it pushes eastward. However, a new low pressure trough will deepen over Northern California with the jet stream nosing back into the Northern Rockies.
Moisture will increase over the Northern Rockies, which, combined with steep lapse rates over the region (rate of temperature decrease with height), will support an unstable atmosphere with scattered thunderstorms developing in the afternoon.
Most storms will produce light to moderate rainfall and small hail, but localized downpours are possible underneath any stronger storms that develop.
Friday (June 20) to Saturday (June 21):
A more impactful system will impact the Northwest as a trough deepens across the area and a strong cold front moves through, eventually bringing cooler temperatures to nearly the entire West.
Pacific moisture will also arrive with this system, resulting in widespread significant rainfall across Washington, Oregon, Northern Idaho, and Western Montana.
The cold front will move through the Cascades on Friday with rain developing. Ahead of the cold front, thunderstorms are expected over the Interior Northwest and Northern Rockies (Eastern Washington, Idaho, Montana) on Friday.
On Saturday, the cold front will track across the Interior West with widespread rain reaching the Northern Rockies with a reduced threat of thunderstorms.
As the colder airmass takes hold, snow is likely to develop over the higher elevations of the Cascades and Northern Rockies.
5-Day Precipitation Forecast (June 17-21):
Here is the 5-day rainfall outlook from the European Weather Model through Sunday morning. This particular model is projecting Oregon to receive the heaviest rainfall from the Friday-Saturday system, but we'll see how this looks as we get closer.
The European Model is also catching onto snowfall across the higher elevations of the Cascades and Northern Rockies. The area that stands out the most is north of the border across the Canadian Rockies, where the potential for heavy snowfall exists.
Extended Forecast
Outlook for June 22-26:
Next week, a trough-dominant pattern is projected across the West with a ridge-dominant pattern setting up over the Eastern U.S. This will favor cooler temperatures across a larger portion of the West.
An increased southerly flow between these two features is expected to transport an early-season surge of monsoonal moisture into the Southwest, with New Mexico favored for the moisture uptick.
Below-normal temperatures are expected across much of the West, with relative heat relief over the deserts, while Colorado is expected to see near-normal temperatures. A warming trend is also expected over the Northwest coast.
Rain chances will be elevated across the North Cascades, Northern Rockies, and Eastern Rockies, while the most notable uptick in rainfall and thunderstorm potential is expected across New Mexico and Southeast Arizona.
Thanks so much for reading! Next update on Wednesday (June 18).
Alan Smith
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