A potent storm system off the California coast is driving active weather across the region, bringing the threat of strong thunderstorms with gusty winds, hail, and heavy rain this afternoon and evening. The unsettled pattern will continue through the weekend, followed by a cooler and showery week ahead.
Scott Dorval's video forecast tracking storms and an unsettled weekend
Strong Storms Peak This Afternoon and Evening
Showers are already occurring over eastern Oregon near Burns and Baker City this afternoon, keeping temperatures cooler than forecast in those areas. This has created a temperature gradient across the Snake Basin toward Mountain Home, generating breezy northwest winds down the Treasure Valley.
The main concern is strong storms forming in central Nevada that will lift northward later this afternoon and evening, bringing scattered showers and thunderstorms to the region. The primary threats with these storms will be wind gusts up to 55 mph, heavy rain, and hail up to 1 inch in diameter.
The best chances for these strong storms will generally be over extreme southeast Oregon and southwest Idaho, south of the Snake Basin. The main wind threat will occur between 3 p.m. and 11 p.m. MDT this evening. These storms will continue into the night as the best atmospheric dynamics move slowly east.
Intermittent Showers Continue Through the Weekend
While scattered showers and isolated thunderstorms will continue into Saturday and Sunday, the thunderstorms are not expected to be as strong as today's activity. Temperatures will cool by about 10 degrees by Sunday as the low-pressure system moves directly overhead.
Active Pattern Continues Monday
The upper-level low creating this active weather pattern will continue moving through the Great Basin and Intermountain West region on Monday. This will bring widespread high precipitation chances (50 to 90%) across the region. However, thunderstorm chances will be isolated due to cooler surface temperatures during peak heating hours and less instability aloft.
Snow levels will drop to 4,000 to 5,000 feet on Monday night, with snow accumulations largely limited to higher mountain peaks. Winds will remain breezy on Monday and Tuesday as this trough exits the Rockies.
Brief Break Tuesday Before Next System Arrives
The low will exit the region by early Tuesday, bringing a brief return to mostly dry and mild conditions thanks to a short-lived upper-level ridge.
However, shower chances quickly return Wednesday as another trough deepens into the region from British Columbia. This system will bring much colder air and precipitation late Wednesday into Thursday. How far south this low tracks will heavily influence temperatures and snow levels for this event.
Precipitation will taper off Thursday and even more so on Friday behind the trough and its associated cold front. Persistent northwest flow aloft and multiple cold fronts will keep temperatures below normal throughout the extended forecast period.
Tonight
Showers and thunderstorms before 2am, then a chance of showers. Low around 49. Locally gusty wind to 45 mph during evening storms. Chance of precipitation is 80%.
Saturday
Showers and possibly a thunderstorm, mainly before 2pm, then a chance of showers and thunderstorms after 2pm. High near 66. Lighter wind. Chance of precipitation is 80%.
Saturday Night
A 40 percent chance of showers, mainly after midnight. Mostly cloudy, with a low around 46. Light and variable wind.
Sunday
Showers, with thunderstorms also possible after noon. High near 60. Light and variable wind. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Sunday Night
Showers likely, mainly before midnight. Mostly cloudy, with a low around 41. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.
Monday
Showers likely. Mostly cloudy, with a high near 55. Chance of precipitation is 70%.
Monday Night
Mostly cloudy, with a low around 38.
Tuesday
Mostly sunny, with a high near 60.
Tuesday Night
A 20 percent chance of showers after midnight. Mostly cloudy, with a low around 42.
Wednesday
Showers likely. Mostly cloudy, with a high near 57. Chance of precipitation is 60%.
Wednesday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 34.
Thursday
A slight chance of rain and snow showers. Mostly sunny, with a high near 52. Chance of precipitation is 20%.
Thursday Night
Partly cloudy, with a low around 31.
Friday
Mostly sunny, with a high near 58.
