My Favorite Summer Weather Map Layers:

• StormNet Lightning Risk
• Current Lightning Strikes and 1-Hour Risk
• Current Radar
• Forecast Radar
• Forecast Total Precipitation
• Current Air Quality
• Smoke Surface Forecast (ground level)
• Smoke Sky Forecast (average smoke ground level to upper atmosphere)
• Forecast Air Quality (low-res 3-5 day smoke outlook)

5-Day Big Picture Overview:

A trough-dominant pattern will remain over the West this week, leading to below-average temperatures west of the Divide, while frequent Pacific disturbances will bring showers and thunderstorms from the PNW to the Northern Rockies.

Further south, dry conditions will prevail across the Southwest and Southern Rockies along with breezy winds and high fire danger, though fire conditions will not be as extreme compared to last weekend at least.

5-Day Regional Forecast Breakdown below as follows...

• Colorado
• Utah
• Southwest
• California/Sierra
• Pacific Northwest
• Northern Rockies
• BC Interior & Canadian Rockies

COLORADO

Mon – It was a bummer of a weekend as numerous large wildfires ignited west of the Divide and spread quickly in a dry/windy environment. Smoke from fires in Utah and Colorado has resulted in poor air quality at times. 

More of the same can be expected on Monday with dry conditions, and while it won't be as windy or as hot as recent days, fire activity will still flare back up with daytime heating, with smoke transport also increasing from SW to NE across much of the state.

Tue – The weather pattern will turn slightly more active for areas near and east of the Divide, but significant moisture is not expected to arrive.

A trough will move across the Four Corners region and will help to draw in marginal amounts of moisture in from the south and southeast, leading to a chance of isolated to scattered afternoon thunderstorms across the eastern mountains (Front Range, Sangre, Pikes Peak).

Storms will only produce light/spotty rain and strong outflow winds. Thunderstorm chances will be lower west of the Divide.

Winds aloft will shift slightly from SW to SSW, and as a result, smoke transport is expected to take more of a SSW to NNE trajectory, which will lead to slight geographic variations in which areas experience heavier smoke.

Also note that smoke will tend to settle in valleys during the mornings (see the Smoke Surface Map Layer) before dispersing but eventually increasing downwind of the fires as fire activity increases with daytime heating.

Wed – Weak upslope flow (east winds) east of the Divide will lead to a chance of thunderstorms mainly across the northeast plains of Colorado, with lower probabilities across Denver Metro and over the Front Range foothills. Little to no thunderstorm activity is expected west of the Divide or south of Colorado Springs.

Thu-Fri – More of the same is expected with thunderstorm chances largely confined to the northeast plains, with just a slight chance of storms along the Front Range (east of the Divide) and no thunderstorms expected west of the Divide.

Wildfire smoke is likely to be an issue throughout the week as fires continue to burn. Fire danger will not be as extreme this week compared to last weekend, but breezy afternoon winds and seasonally hot temperatures will still keep fire danger and spread potential high. 

UTAH

Mon – Quite the contrast across Utah recently. Large fires burning over central and southern portions of the state (granted with less extreme weather conditions now), while cooler and wetter weather has brought some relief to Northern Utah. The Wasatch has even been dusted with snow over the past 24-36 hours.

Light showers are tapering off across Northern Utah on Monday AM, but temperatures will remain well below average, which will aid in firefighting and suppression efforts.

Across Southern Utah, the Cottonwood Fire east of Beaver and the Babylon Fire south of Moab will be the biggest smoke producers on Monday, with smoke transport expected to the NE of these fires (due to SW winds aloft).

Tue – A moisture-starved trough will move across Utah, resulting in just a slight chance of thunderstorms across the Tushars (near the Cottonwood Fire), Wasatch, and far Northern Utah. This is a dry thunderstorm setup, so any storms will produce only brief/light rain and strong outflow wind gusts.

Smoke will continue to impact central and eastern portions of Utah the most, and we'll keep our fingers crossed that there aren't any new fire starts due to "dry" lightning.

Wed-Fri – Another trough will deepen along the West Coast before gradually moving inland, with enough moisture and energy tracking across Northern Utah for a chance of afternoon thunderstorms each day. Mainly across the Wasatch, SLC Metro, Uintas, and Bear Rivers.

Significant rainfall is not expected in this pattern, though localized downpours couldn't be ruled out if any stronger storms develop.

Dry conditions will continue across Southern Utah, and while fire danger will not be as extreme as last weekend, warm and moderately breezy conditions will still favor active fire behavior. 

SOUTHWEST

Mon – There was a big uptick in fire activity over the weekend, with active fires burning near the Grand Canyon South Rim, Flagstaff, Taos, and Silver City. Smoke from these fires will impact areas to the northeast (downwind) on Monday, while conditions will remain dry across the area.

Tue – A trough will move across the Four Corners and will pull in just enough moisture from the south to result in afternoon thunderstorms across New Mexico, while Arizona will stay dry. 

Moisture levels will be marginal, so this looks like a dry thunderstorm setup across the higher terrain of NM with storms producing light/spotty rain and strong outflow winds. East of the mountains, moisture levels will be a bit higher, so storms could produce locally heavy rain.

Wed-Fri – Most areas will stay dry, though weak moisture return over southern/eastern New Mexico will result in daily thunderstorm chances around Ruidoso and the San Francisco/Sierra Blanca Mountains. 

Winds will not be as strong as last weekend, but still enough to fuel active fire behavior and high fire danger each day.

CALIFORNIA/SIERRA

Mon – Below-average temperatures will prevail while an upper-level low-pressure area will track from north to south through California. This will pull in enough moisture from the north to result in isolated to scattered afternoon and evening showers and thunderstorms across the Sierra.

Hourly lightning odds are relatively low, but the best chance of lightning will be over the northern and eastern Sierra from mid-afternoon to early evening.

With a chilly airmass in place, any showers will likely produce snow over the higher peaks of the Sierra, with snow levels ranging from 10,000 to 11,000 feet. While any snowfall is probably going to be light and spotty, some of the higher peaks could get dusted. 

Tue-Fri – The rest of the week will be dry and slightly warmer than recent days, but still cooler than average for the end of June and beginning of July. Breezy winds can be expected each afternoon on the lakes and on the peaks, but not as windy as last Friday/Saturday.

PACIFIC NORTHWEST

Mon – Cool and damp conditions with light rain and drizzle will prevail along and west of the Cascade Crest and in the BC Coast Range.

East of the Cascade Crest in Washington, scattered showers and thunderstorms will develop in the afternoon in response to an upper low over Montana, with locally heavy rain expected across the mountains of Northeast Washington.

A moderate threat of lightning can also be expected across NE Washington during the afternoon and evening hours.

Tue-Wed – Another low pressure trough will arrive with continued cool temperatures and rain showers favoring the Washington Cascades, Olympics, BC Coast Range, NE Washington Mountains, and Blue/Wallow Mountains in Oregon. The highest rain totals are expected across NE Washington with lighter rain for the Cascades.

Also, the thunderstorm threat is lower across the Inland NW compared to Monday, but isolated lightning can't be ruled out on either day.

Thu-Fri – Yet another trough will arrive, bringing more showers, cloudy skies, and cool temps to Washington and the BC Coast Range, while Oregon looks to see drier conditions with more sunshine.

Our PEAKS Model 5-day precipitation forecast map indicates light rainfall (but persistently cloudy/wet) across the Cascades and western portions of the PNW this week, while NE Washington is favored for heavier rain amounts.

NORTHERN ROCKIES

Mon – A low pressure system will continue to impact the region, bringing significant rain to Western Montana, Northern/Central Idaho, and Northwest Wyoming, while the higher elevations will receive snow as temperatures will be well below average for this time of year.

Snow levels are starting out below 8,000 feet in many areas, but will generally rise to 9,000-10,000 feet in the afternoon.

Tue – Temperatures will start to warm up from Monday's unseasonably cool levels, but another trough will move into the Great Basin with moisture/energy arriving from the southwest. This feature will lead to scattered showers and isolated thunderstorms, favoring Central/Northern Idaho and Western Montana for the highest rain amounts.

Wed – Another shortwave trough will approach from the west with a warmer and more unstable airmass in place. The result will be scattered thunderstorms across Idaho, Western Montana, and Western Wyoming with a higher threat of lightning across the board compared to prior days.

Thu-Fri – More of the same can be expected with daily rounds of afternoon thunderstorms. Friday looks like the more active of the two days as a more robust shortwave trough moves through.

Total rain amounts over the next 5 days will favor Western Montana and North/Central Idaho.

BC INTERIOR & CANADIAN ROCKIES

Mon – It has been a wet stretch across this region lately, especially on the Alberta side with significant rainfall and some flooding concerns.

Rain will continue on Monday, mainly south of Calgary across the Southern Canadian Rockies and Lizard Range/Fernie in Southeast BC. Scattered afternoon thunderstorms will also develop across the Southern BC Interior.

One unfortunate element of Monday's pattern is the arrival of wildfire smoke and poor air quality across Alberta, due to strong northeast winds transporting smoke from wildfires in the Northern Canadian Prairies. Fortunately, this smoke event looks to be short-lived before winds turn westerly on Tuesday.

Tue – A break will occur over the Canadian Rockies in the morning, while the next disturbance will bring rain to the Okanagan region during the morning, before filling in across Eastern BC and Alberta, including the Rockies, in the afternoon. Scattered thunderstorms can also be expected.

Wed-Fri – A wet and active pattern will continue with daily rounds of scattered showers and isolated thunderstorms. Locally heavy downpours can be expected each day.

Significant rain amounts are expected across this region over the next 5 days.

Saturday (July 4) to Wednesday (July 8):

Most of the West will see a warmer and drier pattern this weekend into early next week as a ridge of high pressure builds over the Interior West.

Western Canada, Washington, and the Northern Rockies may see occasional weak disturbances slide in with shower/thunderstorm chances, but it does not look as wet compared to what we've seen lately.

We may see some weak monsoonal moisture pushes into New Mexico and Southern Colorado at times with a chance of thunderstorms, but no major monsoon moisture upticks are expected for now. 

Thanks so much for reading! Next update on Thursday (July 2).

Alan Smith