We're trying out a new format that we think will be more user-friendly, where we will be breaking up the discussions into smaller regions of the West. That way, you can more easily view the outlook for your area, instead of having to sift through the large-scale details.

The regions will be as follows....

• Colorado
• Utah
• Southwest (NM, AZ, Southern NV)
• California/Sierra
• Pacific Northwest (WA, OR, North ID, BC Coast)
• Northern Rockies (ID, WY, MT)
• Interior BC & Canadian Rockies

COLORADO

The first heatwave of the season is taking hold, and low elevations are going to see hot temperatures over the next 5 days, with mainly isolated afternoon thunderstorms that produce brief rain. Denver and lowland areas will see highs well into the 90s.

Fri – Scattered thunderstorms will develop over the San Juans and Sangres by midday in response to an upper-level low-pressure area over New Mexico. Isolated storms are also possible over the Central Mountains and around Pikes Peak, with little to no storms north of I-70.

Sat – A similar setup with scattered early afternoon thunderstorms favoring the San Juans, Sangres, and Pikes Peak. A few stray late-day storms are also possible over the Front Range Mountains, with mostly dry conditions across the central and northern mountains west of the Divide.

Sun – Winds will pick up across the northern and central mountains as a trough moves into the Northern Rockies. Thunderstorm chances will be highest over the northeast plains, with only some isolated activity expected across the Front Range and San Juans.

Mon – A weak cold front will move through, which will bring only minor heat relief, but gusty winds can be expected in the mountains. Thunderstorms are also possible across all mountain ranges, though most storms will produce light rain (isolated downpours still possible). The greatest threat of lightning will be over the Front Range Mountains and adjacent plains, including the I-25 corridor.

Tue – This looks like a more active day as a trough of low pressure approaches, with a higher threat of thunderstorms statewide along with a better chance of meaningful rain with storms. The best chance of storms currently looks to be over the San Juans and Sangres, but the northern ranges have a good chance of storms as well.

UTAH

Fri-Sat – Hot and dry conditions will prevail statewide, though we could see some isolated thunderstorms develop across Northern Utah on Saturday evening (mainly north of SLC) as a trough approaches. Fire danger will increase across Southern Utah due to gusty winds and low humidity. 

Sun – A cold front will move through on Sunday, bringing strong winds statewide, heat relief to Northern Utah, and isolated thunderstorms with light rain to Northern Utah. Across Southern Utah, thunderstorms are not expected, but strong winds will lead to continued high fire danger.

Mon – Warm and dry conditions are expected statewide, but winds will also remain strong with continued high fire danger across Southern Utah.

Tue – A more active day is expected across Northern and Central Utah as a trough of low pressure approaches along with a stronger cold front. This will result in a better chance of showers and thunderstorms along with meaningful rainfall to northern and central parts of the state.

Across Southern Utah, we could see some showers/storms extend into the Bryce/Cedar City/Brian Head area and perhaps even around Moab, with drier conditions further south toward the AZ border.

SOUTHWEST

Fri – New Mexico will see an active thunderstorm day in response to an upper-level low-pressure area, with storms developing over the mountains by early to mid-afternoon, favoring Taos, Santa Fe, and Ruidoso. Most storms will produce light rain, but localized downpours are possible. Hot and dry conditions will prevail across Arizona and Southern Nevada.

Sat-Sun – An overall drying trend is expected. New Mexico will see some isolated thunderstorm activity in the mountains on Saturday, with minimal activity expected on Sunday. Winds will pick up both days in advance of an approaching cold front on Sunday, and this will lead to high fire danger across Arizona on both days.

Mon – Thunderstorm chances return to NM as a trough of low pressure approaches, while drier air will remain in place over Arizona with gusty winds and high fire danger. 

Tue – This is shaping up to be a more active day for NM as the trough pushes into the Southwest, with stronger and more numerous thunderstorms possible across New Mexico. Our StormNet Model is also picking up on a risk for severe thunderstorms capable of producing 1+ inch diameter hail, even in the mountains.

Arizona will see cooler temperatures as a cold front arrives, but strong winds and low humidity will result in continued high fire danger.

CALIFORNIA/SIERRA

Fri-Sun – Warm and sunny conditions on Friday will give way to cooler temperatures Sat-Sun as a cold front moves through. Strong winds can also be expected on Fri-Sat, before trending lighter on Sun.

There are a few active fires across the Sierra foothills, which will lead to isolated smoky/hazy skies this weekend, mainly over the Central Sierra and in the foothills near Oroville. 

Mon-Tue – A stronger trough will arrive with some moisture, bringing a good chance of rain showers to parts of Northern California. Confidence is relatively low in the placement amounts of precip, but for now, the best chances of measurable rain look to be over the NW Coast, Mt. Shasta, Trinity Alps, and Northern Sierra foothills, with potentially fewer/lighter showers around Tahoe.

PACIFIC NORTHWEST

Fri-Sat – A trough will move across the area, resulting in chilly temperatures and widespread rain showers across the Cascades and BC Coast Range. Rain totals of an inch or more will favor the North Cascades and South Coast Mountains in BC, with light to moderate totals extending into Oregon as well as NE Washington.

Cold air (for June) will accompany this system, with snow levels dipping as low as 4,000-5,000 feet from Whistler to Baker to Rainier to Hood. 

Sun – This will be the best weather window of the weekend along and west of the Cascades, as we will be in between systems. There will still be some cloud cover across western areas, while Eastern WA and Northern ID will hang onto scattered showers.

Mon-Tue – A second stronger storm system will arrive, resulting in more widespread rain. Two-day rain totals are projected to range from 1-2 inches across the Cascades and BC Coast Range, with these higher totals extending further south into Oregon as well.

Also, the Inland NW will see more widespread rain showers and higher rain totals compared to the Fri-Sat system. There is a chance of thunderstorms for the Inland NW on Tuesday as well.

Even though this system will be stronger, it will not be as cold as the last system. As a result, snow levels will be higher, ranging from 5,500-7,000 feet.

NORTHERN U.S. ROCKIES

Fri – Warm and dry conditions will prevail with gusty winds ahead of an approaching weekend low pressure trough.

Sat-Sun – A trough will move across the area, along with an associated cold front, bringing scattered showers and only a slight chance of thunderstorms, with most lightning activity remaining confined to the eastern plains of MT and WY.

Most areas will see less than a quarter of an inch of rain this weekend, but isolated higher totals of quarter to a half inch or more are possible near and east of the Divide in Montana. 

Mon-Tue – Most areas will see a break during the day on Monday with warmer/drier conditions, then a stronger trough will push into the Northern Rockies on Monday night-Tuesday with more numerous showers developing along with a chance of thunderstorms.

This second system looks like it will bring a longer duration cool and wet period that lasts through late next week.

INTERIOR BC TO CANADIAN ROCKIES

Fri-Sun – Cool and unsettled conditions will prevail through the weekend with off-and-on showers expected, along with a chance of afternoon thunderstorms each day. 

Higher elevation areas are looking at anywhere from 0.75 to 1.5 inches (17-38 mm) of precipitation through Monday morning, with 0.25-0.75 inches (7-17 mm) for many interior valleys as well. Snow levels are projected to range from 5,500-7,000 feet.

Mon – A relative lull in the pattern is expected on Monday, though some isolated showers/thunderstorms are still possible in the afternoon. Still, it looks like a relative weather window compared to surrounding days.

Tue – the next system will arrive with more numerous showers developing along with a chance of thunderstorms in the afternoon. 

Wednesday (June 10) to Friday (June 12):

A slow-moving trough of low pressure will linger over the Interior West during the second half of next week, resulting in much cooler temperatures across the Rockies along with a good chance of rain for the Central and Northern Rockies. 

Montana and Alberta are favored for the highest precipitation totals during this stretch, while Idaho, Wyoming, and Northern Utah should also pick up some beneficial moisture. Across Colorado, rain chances (and thunderstorm chances) will favor the northern half of the state with drier conditions further south.

Colder air arriving with this system will also result in a chance of high-elevation snow, so that will be something to keep an eye on as we get closer. 

June 13-16:

Heading into the weekend of June 13-14, and into the start of the week of June 15th, a strong ridge of high pressure is projected to build over the West Coast and eventually push inland.

This will likely result in the first heatwave of the season across the western states from CA to the PNW. The Rockies may see some lingering chilly temperatures initially next weekend, but the warmth will eventually spread inland as well.

Confidence is low in terms of how long this hot/dry spell will prevail. Some models are hinting that the ridge could weaken by the end of next week (~June 18-20), but we'll have a better idea of this as we get closer.

Thanks so much for reading, and have a great weekend! Next update on Monday.

Alan Smith