There will only be subtle changes to the weather pattern over the next 5 days with well-above-average warmth and little rainfall continuing to be the theme as a ridge of high pressure remains in place over the Western U.S. The previously wet Pacific Northwest will start to dry out as well.

Check out these OpenSummit maps for the latest conditions regarding wildfire smoke and lingering snow conditions across the higher terrain:

Near Surface Forecast Smoke Map

Upper Atmosphere Forecast Smoke Map

Snow Depth Map

These are just a few of the useful tools available on OpenSummit with an All-Access subscription to help you plan your outdoor adventures.

Forecast for Wednesday, June 16

The ridge of high pressure in place over the Western U.S. will "flatten" somewhat on Wednesday with the core of the hot temperature anomalies shifting south into the Southern Rockies/Desert and west into California. The Pacific Northwest will also start to warm up following a stretch of cool and wet weather. 

Wednesday is looking very dry across most of the West. This will be a welcome change for the previously sun-starved Pacific Northwest, but not so much for the rest of the West where drought conditions persist.

Isolated thunderstorms are expected to develop across Colorado and to a lesser extent the remainder of the southwest, but these will be "dry" thunderstorms with minimal rainfall. Still be prepared and watch the skies closely as cloud-to-ground lightning is a threat with any thunderstorm, no matter how "weak". 

Forecast for Thursday, June 17

Hotter than average temperatures are expected across the board throughout the West, with brutal heat at near record levels for the desert and valley regions especially. Higher elevation areas and also the Pacific Northwest coastal regions will offer the most pleasant conditions.

The pattern will remain dry overall, though isolated thunderstorms with minimal rainfall can be expected across the higher peaks in Colorado and New Mexico and also in the Sierras in California. 

Forecast for Friday, June 18

Most of the West will stay hot, though a backdoor cold front will cool things off slightly east of the Divide in Montana.

A subtle uptick in subtropical moisture from the south will result in greater coverage of thunderstorms on Friday afternoon across the Four Corners states though most storms will only produce light rain.

Forecast for Saturday, June 19

Little change to the temperature pattern is expected on Saturday with above-average warmth continuing for most areas. Another backdoor cold front will slide into Montana east of the Divide. 

Moisture via easterly upslope flow will increase behind the cold front in Montana on Saturday, and as a result showers and thunderstorms are expected to develop along and east of the Continental Divide from Glacier National Park south to the Bighorns in Wyoming.

Thunderstorm coverage will continue to increase across Colorado and New Mexico as well with storms producing a bit more rainfall compared to prior days. Thunderstorm activity will remain more isolated and with less rainfall farther west in Utah and Arizona.

Forecast for Sunday, June 20

For Father's Day on Sunday, well-above-average warmth will expand northward into Oregon and Washington. Meanwhile, a cold front east of the Divide will dip south into Wyoming and Colorado, offering a nice reprieve from the heat.

The best chance of thunderstorms on Sunday can be expected along and east of the Divide from Montana to Northern New Mexico. Moisture will decrease west of the Divide during this time with fewer thunderstorms expected as a result. 

Outlook for Mon, June 21 – Fri, June 25

The heat should gradually begin to relax west of the Continental Divide next week, though temperatures will remain above average. East of the Divide, a northwest flow pattern will persist with additional backdoor cold fronts expected periodically.

Areas along and east of the Divide will see the greatest thunderstorm potential and best chances of measurable rains next week in response to moisture arriving from the Great Plains. This is especially true for northerly areas such as Montana and Wyoming.

A trough of low pressure is also projected to set up near the West Coast later next week, with increasing moisture and energy downstream of the trough expected to trigger some thunderstorm activity from time to time in the Rockies west of the Divide. 

Thanks so much for reading! I am going to be away for most of the next 2 weeks, so Meteorologist Sam Collentine will be taking over forecasting duties while I'm gone. Check back for our next forecast on Friday, June 18th.

ALAN SMITH