An active pattern will continue across the West this week with frequent showers and thunderstorms across most regions. Strong thunderstorms (lightning, gusty winds, hail) can be expected across the Sierra and parts of ID/MT on Monday. The threat of strong storms will persist around Tahoe and parts of the Great Basin through midweek as well as the CO Rockies.
Short Term Forecast
Forecast for Monday:
A large area of low pressure is moving into Southern California on Monday. Winds blowing counterclockwise (cyclonically) around the low will transport moisture into the Sierra Nevada Range, Northern California, and Central Nevada where numerous showers and thunderstorms can be expected on Monday afternoon.
Stronger storms will be capable of producing frequent lightning, heavy rain, hail, and strong wind gusts. There is also a chance we could see a few storms reach "Severe" criteria across this region, meaning 1" diameter or hail and/or localized wind gusts in excess of 58 mph.
A second focus area of stronger storms will be across parts of Central Idaho and Western Montana in response to a smaller area of low pressure moving from south to north across Idaho. Widespread showers and thunderstorms are expected across this region, and we could see a few severe thunderstorms as well.
Elsewhere across the West, an active day can be expected across the Colorado Rockies with locally heavy rain possible, favoring areas near and east of the Continental Divide. Northern New Mexico will be included in this action as well.
Thunderstorms will be more isolated in coverage across Utah and Wyoming. Across the Pacific Northwest, the Southern Oregon Cascades will see some storms with dry conditions further north into Washington and BC.
Storm Tracking Tools:
Forecast for Tuesday:
The low over California will start to move northward ever so slightly with strong to severe thunderstorms possible across the Sierra, Northern California, and Northern Nevada, while isolated strong/severe thunderstorms will be possible into SLC and the Wasatch of Utah as well.
Locally heavy rain will also be possible under thunderstorms, and this includes the coastal ranges of California where widespread showers/thunderstorms are expected.
Across the Rockies, widespread afternoon thunderstorms can be expected across portions of Colorado and New Mexico with more scattered/less widespread storms in Wyoming, Idaho, and Montana. Locally heavy rain will be possible under stronger storms all across the Rockies, however.
Forecast for Wednesday:
The highest threat for strong/severe thunderstorms will shift northward a bit into NorCal, Southern Oregon, and Southern/Central Idaho while the Sierra Nevada Range will still see scattered to numerous afternoon thunderstorms as well.
A general uptick in storms can also be expected across the Rockies from Montana to New Mexico. Locally heavy rainfall will be possible with stronger thunderstorms throughout the West.
Forecast for Thursday to Friday:
The area of low pressure will slowly meander into the Inland Northwest during this period with increasing moisture resulting in the potential for widespread showers and thunderstorms with locally heavy rain across a larger region.
The wettest/stormiest zones look to be the Northern Rockies and Inland Northwest, including parts of the Cascades (especially the eastern slopes). Southern portions of BC and Alberta could receive some much-needed rain as well.
The Colorado Front Range also looks like a potentially wet/active region during this time with abundant moisture arriving from the Gulf of Mexico.
Meanwhile, another area of low pressure will work its way into Southern California with moisture upstream of this low increasing across the Sierra Nevada Range and across the state of Nevada where thunderstorms and locally heavy rain can be expected.
Outlook for Sat, June 10 to Wed, June 14:
Another slow-moving area of low pressure will impact the West during this period, resulting in wetter-than-average conditions for mid-June across just about the entire West.
Temperatures are expected to be cooler than average across California, the Southwest, and the Southern and Central Rockies, with warmer-than-average temperatures across the Pacific Northwest and Northern Rockies.
Thanks so much for reading! Next update on Wednesday (June 7).