June was a wet and stormy month for much of the West from the Sierra to the Central and Eastern Rockies, while many areas also experienced below-average temperatures. July is shaping up to be a quieter month overall with seasonal summer warmth, while fire danger is expected to increase across the PNW and Western Canada.

June 2023 Review

June picked up right where May left off with an active pattern across the West. A trough of low pressure became the dominant feature across California for much of the month, with southwest flow favoring frequent showers and thunderstorms across the Sierra, Great Basin, and Central/Northern Rockies.

The wettest areas were along the eastern slopes of the Continental Divide in the Northern/Central Rockies where abundant Gulf of Mexico moisture played a role in numerous rounds of strong thunderstorms along with locally heavy rain and flash flooding.

Severe weather was common this month east of the Continental Divide as well, including numerous instances of damaging hail while there were also a couple of tornado outbreaks just east of the Rockies in Colorado and Wyoming. One of the most notable events of the month was a hail storm that injured 80-90 people attending a show at Red Rocks Amphitheater in Colorado.

Rainfall was below average during June across the Pacific Northwest, although a system did bring several days of needed rain as well as a few thunderstorms during the third week of the month. Rainfall was also below average across Arizona and Western New Mexico, though June is considered the pre-monsoon dry season in these areas anyways.

Temperatures were cooler than average across most of California, as well as the Great Basin, Southwest, and Central Rockies during June. The Southwest did not see any true summer heat (by local standards) until late in the month.

Temperatures were warmer than average in June across the Pacific Northwest and Far Northern Rockies. 

July 2023 Outlook:

The first few days of July have started out active across the Northern Rockies as well as areas east of the Divide in Wyoming and Colorado. Most areas are expected to see a trend toward drier mid-summer conditions as the month progresses, however.

Many areas of the West have "equal chances" for above or below-normal rainfall in July per NOAA's Climate Prediction Center.

Areas east of the Divide in Colorado and Wyoming have slightly favored odds of above-normal rainfall.

Arizona and the core monsoon region is expected to have below-normal rainfall in July, and this is due in part to a late arrival of the North American Monsoon.

However, there are now some signs emerging that the monsoon will slowly get going around mid-July. This will likely result in a gradual uptick in thunderstorms across the Southwest, Canyon Country, and Colorado Rockies at a minimum during the second half of the month.

Temperatures are expected to be hotter than average across the Southwest during July, which may largely be a result of the delayed start of the monsoon, which can help to temper summer's heat at times due to increased moisture and cloud cover. 

Temperatures are expected to be cooler than average along the east side of the Divide in the Central Rockies, while the Pacific Northwest is slightly favored for above-average warmth. California as well as the Great Basin and Utah have equal chances for above or below-average temperatures.

It is July, so heat waves will certainly be possible at times, but this outlook from NOAA does not look too severe as far as summer heat goes. In other words, the odds of long-term periods of sustained above-average heat appear to be lower this July compared to some of our more recent Julys. 

Fire and Smoke Outlook:

Significant wildland fire activity is expected to be below average across the Sierra and much of California this July, thanks to a record-setting snow season followed by a cooler and wetter-than-average spring and early summer. 

The Pacific Northwest has a greater chance of experiencing significant wildfires this month, as snowfall was less impressive in this region last winter and the spring/early summer has also been warmer and drier than average.

The Central Rockies are unlikely to see widespread/severe fire activity this month following a wet spring and early summer. Fire danger does look higher across Arizona and Southern Utah, due in part to the delayed start to monsoon season expected this month. 

North of the border, it's no secret that Canada has had a rough start to fire season – both eastern and western Canada.

While rainfall in June along with the seasonal green-up of fuels have helped to reduce fire behavior across Western Canada recently, Environment Canada is projecting above to well-above-average potential for fire severity across all of Western Canada (and most of Canada as a whole) during July.

As far as smoke goes, the PNW and Western Canada will be most vulnerable this month as this is where fire danger is expected to be highest. But of course, this is all speculative depending on if and when old fires flare back up and/or if new large fires ignite. 

If we get periods of north or northwest winds aloft across Western North America, then areas further south in the U.S. could see occasional smoke arriving from Canada (and maybe the PNW), but for many areas, this month is not expected to be too smoky as a slow start to fire season is anticipated across the Sierra and Central Rockies.

Alan Smith