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:

Most of the West will see a warming trend over the next 5 days, but cooler air (relative to average) will linger across California and Western Canada. Weaker Pacific disturbances will keep some shower and thunderstorm chances going across the PNW and Northern Rockies, with lighter rain compared to the past week. 

Across the Southern Rockies, drier conditions will prevail west of the Divide with thunderstorm chances entering the picture east of the Divide, while no significant relief from fires and smoke is expected. 

COLORADO

Thu – Seasonally hot and dry conditions with smoky skies will prevail across most of the state, with continued high fire danger as winds pick up in the afternoon (a daily theme for the next several days at least). Southwest winds aloft will favor the heaviest smoke transport across Central and Northern Colorado.

There is only a slight chance of some isolated thunderstorms along the eastern slopes of the Front Range and northern plains, mainly north of the Palmer Divide. Moisture is limited, so any storms will produce light/spotty rain and strong outflow winds.

Fri – A subtle wind shift to west/southwest will keep the heaviest smoke confined to central portions of Colorado, with lighter smoke across far northern Colorado compared to prior days.

Isolated thunderstorm chances will be confined to northern areas close to the Wyoming border (Steamboat to Ft. Collins) in response to a shortwave trough moving across the Northern Rockies. Any storms will produce light rain and gusty winds.

Sat – Low-level moisture will reach the Front Range from the east on Saturday behind a weak backdoor cold front moving through the plains. This will result in a better chance of thunderstorms across the Front Range and eastern mountains, with even higher chances further east out on the plains.

Moisture levels will still be somewhat marginal, so most storms will produce brief and light rain, but stronger storms will be capable of producing locally heavy downpours. 

Across the high country, thunderstorm chances will be greatest right along the Continental Divide and along the eastern side of the Sangres, while minimal thunderstorm chances are expected west of the Divide.

Not much change is expected in the smoke and wildfire situation. Fire danger will remain high, and smoky conditions will prevail across much of the state (heaviest to the east of active wildfires).

Sun – Moisture will decrease with only some low-end isolated thunderstorm chances along and just east of the Continental Divide, with drier conditions expected west of the Divide and across the eastern plains. 

Mon – A weak push of monsoonal moisture will arrive from the south, resulting in a better chance of scattered thunderstorms throughout the state (west and east of the Divide). This does not look like a heavy rain setup. Most storms are expected to produce light rain and gusty winds, but stronger storms could produce locally heavy downpours. 

UTAH

Thu – A shortwave trough will move across Northern Utah, resulting in scattered thunderstorms, favoring Logan and areas north of SLC toward the Idaho border, with more isolated activity around SLC and the Wasatch. Moisture will be limited, so this looks like a dry thunderstorm setup with most storms producing brief/light rain and gusty outflow winds.

A couple of large fires are still burning in Central/Southern Utah, but smoke impacts have not been as widespread as they were last week. 

The heaviest smoke issues will be downwind of the Cottonwood Fire near Beaver and the Babylon Fire south of Moab.

Fri-Sun – Thunderstorm chances will mainly be confined to the Bear River Range/Logan area and the Uinta Range, with drier conditions around SLC and the Wasatch. Most storms will produce only light rain and gusty winds, though some localized downpours are possible over the Uintas on Friday.

Temperatures will also heat up substantially over the holiday weekend as high pressure builds over the Central Rockies.

Mon – A weak push of monsoonal moisture from the south will result in isolated to scattered thunderstorms across most of the state. Low-level moisture will be limited, so this looks like more of a dry thunderstorm setup with most storms producing only light rain and gusty winds.

SOUTHWEST

Thu-Fri – Dry conditions will prevail across most of the area except for some isolated afternoon thunderstorm chances around Ruidoso (Sierra Blanca/Sacramento Mtns) both days.

The Pocket Fire near Sedona will continue to produce heavy smoke across the Flagstaff area. Also, the Sacaton Fire in Southwest New Mexico will send waves of smoke into Central and Northern New Mexico at times. Prevailing winds (and smoke transport) will be from SW to NE.

Sat-Sun – A little bit of moisture will sneak into eastern and southern New Mexico from the east, resulting in isolated to scattered thunderstorms across most mountain ranges. Most storms will produce light rain and gusty winds, but stronger storms could produce locally heavy downpours. Of the two days, Sunday looks a bit more active than Saturday. Conditions will remain hot and dry across Arizona.

Mon – A weak push of monsoonal moisture from the south will result in a chance of afternoon thunderstorms across all mountain ranges of New Mexico and across eastern portions of Arizona. Locally heavy downpours will be possible with any stronger storm cells.

CALIFORNIA/SIERRA

Thu-Fri – Dry conditions will prevail with below-average temperatures on Thursday, giving way to a warming trend on Friday.

Sat-Mon – A slow-moving shortwave trough will move across California, leading to some isolated and spotty shower and thunderstorm chances from Saturday night through Monday across the Sierra and across NorCal.

No major precipitation is expected in this pattern and moisture levels will be limited, so any storms will generally produce brief rain and gusty outflow winds. Daily lightning chances will be in the 5-20% range across this region each day, indicative of the isolated nature.

Temperatures will be warmest on Saturday, then a little bit cooler on Sunday and Monday with no major heatwaves anticipated in the near-term.

PACIFIC NORTHWEST

Thu-Fri – A low pressure system moving through will bring rain to the Olympic Peninsula, Washington Cascades, and BC Coast Range on Thursday afternoon and evening, followed by lighter and more intermittent showers on Friday. Conditions will be drier further south into Oregon and even across Southern Washington.

Rain amounts will range from 0.1 to 0.5 inches across Northern Washington and 0.25 to 0.75 inches across Southwest BC, with higher totals north of Whistler.

Sat – Conditions will dry out across Washington on the 4th of July, with lingering low clouds in the morning giving way to clearing skies and brisk winds in the afternoon. Oregon will also be dry and sunny.

Another trough will move across BC but will be centered further north, with rain chances staying north of the Canadian border. Only scattered light rain showers are expected around Vancouver and Whistler with heavier rain showers north of Whistler.

Sun-Mon – Dry and sunny conditions will prevail across most of the area along with a significant warm-up as temperatures rise to above-average levels. A little bit of moisture will sneak into Southeast Oregon, resulting in a chance of thunderstorms both days, mainly south and east of Bend. 

NORTHERN ROCKIES

Thu-Fri – A shortwave trough moving through from the southwest will result in scattered afternoon thunderstorms both days across Eastern Idaho, Western Wyoming, and Southern Montana.

Most storms will produce light rain and gusty winds, but stronger storms could produce locally heavy downpours. Glacier National Park will see a welcome break from the rain after flooding issues developed earlier this week.

Sat – A break in the pattern is expected with warmer and drier conditions as high pressure builds over the Central Rockies.

Sun-Mon – Temperatures will continue to warm up, but another series of shortwaves will arrive from the southwest, resulting in a chance of afternoon thunderstorms both days across Central/Eastern Idaho, Western Wyoming, and Southern Montana.

Similar to recent days, most storms will produce light rain and gusty winds but stronger storms will be capable of producing locally heavy downpours.

BC INTERIOR & CANADIAN ROCKIES

Thu-Fri – Scattered showers can be expected both days (and overnight) as another trough moves across the area, though rainfall will not be as heavy compared to what we've seen lately. Lightning chances will be highest in Alberta and across Southeast BC around Fernie, and locally heavy rain will be possible with any thunderstorms.

Sat-Sun – Yet another trough will move through, but this one will produce more isolated showers and lighter rain overall. On Sunday afternoon, the foothills and adjacent prairies of Alberta will see a higher threat of thunderstorms, with locally heavy downpours possible.

Mon – Dry and sunny conditions will prevail as high pressure builds over the area. A significant warm-up is also expected along and west of the Divide, with below-average temperatures prevailing east of the Rockies in Alberta.

Tuesday (July 7) to Saturday (July 11):

Next week, a ridge of high pressure will build over the Interior West, with above-average temperatures expected, while near-average temperatures will linger near the West Coast of the U.S., and below-average temperatures will prevail across Western BC.

A monsoonal flow will gradually emerge across the Four Corners states as moisture rotating around the building subtropical high lifts northward out of Mexico. Look for afternoon thunderstorm activity to be on the rise across New Mexico, Arizona, Colorado, and Southern Utah. 

Further north, Pacific disturbances will continue to track across the Northern U.S. Rockies and Western Canada, which will also lead to shower and thunderstorm chances. 

Looking further out, long-range models are in decent agreement with more significant monsoon moisture pushing into the Southwest and the Central Rockies after July 11th, which gives these fire-stricken areas some hope of receiving more beneficial rain.

We're still 10+ days away, so no guarantees yet, just something to keep an eye on.

Thanks so much for reading, and Happy Fourth of July!

Alan Smith