Big Picture Weather Pattern:

A trough of low pressure over the Great Basin will interact with moisture from the remnants of Tropical Storm Alberto to produce another day of widespread rain and strong thunderstorms across the Southwest on Friday.

Also, a shortwave moving across the Northern Rockies will interact with abundant moisture on the east side of the Continental Divide to result in strong to severe thunderstorms. 

Thunderstorm activity began to pick up across the Southern Rockies on Wednesday and Thursday as moisture initially arrived.

Check out this capture from our Lightning Risk Map as thunderstorms started to pop over the Colorado Rockies on early Thursday afternoon. The shaded colors indicate lightning risk within the next hour (using satellite data to detect thunderstorm development), while the dots indicate recent cloud-to-ground lightning strikes.

Thunderstorm Tracking Tools:

→ Lightning Risk Map

→ Hail Size Map

→ Current Radar

→ Forecast Radar

Heading into the weekend, subtropical moisture will continue to rotate around a high pressure center that will set up near the AZ/NM/Mexico border. This will be the start of the North American Monsoon and will keep daily thunderstorm chances going across the Southwest and Southern Rockies through next week.

5-Day Precipitation Forecast:

Rainfall from Friday through Tuesday will favor the Four Corners region, with lighter rain for the Northern Rockies and North Cascades. 

Wildfire Updates

The town of Ruidoso, New Mexico, and surrounding communities have been impacted by the South Fork Fire and Salt Fire this week. The South Fork Fire began on Monday and spread rapidly, exhibiting extreme fire behavior and forcing a town-wide evacuation of Ruidoso.

Our Active Fires Map shows the perimeter of these fires surrounding Ruidoso as of Thursday afternoon.

On Wednesday afternoon, we saw a good news/bad news scenario around Ruidoso. A severe thunderstorm developed on top of part of the South Fork Fire, producing large hail and heavy rain, with some estimates of 3-5 inches of rainfall.

The downside of this heavy rain is that it caused flash flooding and mudslides over and below the burn scar, since recently burned soil is unable to absorb much water. The National Weather Service issued a Flash Flood Emergency during this event, and several water rescues were reported in the area.

Elsewhere, a couple of large fires continue to burn in California where it has been hot and dry – the Post Fire (15,690 acres) is burning just north of Los Angeles and the Sites Fire (19,123 acres) is burning northwest of Sacramento. 

Wildfire Tracking Tools:

→ Active Fires Map

→ Real-Time Air Quality Map

→ Smoke High-Res (Surface) Map

Forecast for Fri (Jun 21) to Sat (Jun 22):

Widespread showers and thunderstorms with heavy rain can be expected across the Southwest on Friday. Flash flooding will be possible in burn scars, slot canyons, and dry washes. Also, severe thunderstorms are possible which could produce quarter-size hail and wind gusts of over 60 mph, and there is even a minor risk of tornadoes. 

A shortwave will also move across the Northern Rockies on Friday, with scattered thunderstorms developing along and east of the Continental Divide in Montana and Northern Wyoming. Storms have the potential to reach severe levels in this area as well, with the potential for large hail (quarter to golf ball size or larger) and wind gusts of over 60 mph, along with some tornado risk. 

On Saturday, the pattern will quiet down somewhat with scattered afternoon thunderstorms favoring the higher terrain across the Southwest, and to a lesser extent across Southern Montana. Locally heavy rain and isolated flash flooding will remain possible in vulnerable terrain. 

Colorado:

Thunderstorms can be expected throughout the higher terrain in this pattern, but the Southern San Juans and Western Slope will see the most widespread activity and heaviest rainfall. 

We are forecasting 1.51 inches of rain in Durango on Friday with widespread rain in the morning followed by a good chance of thunderstorms in the late afternoon and evening hours. 

New Mexico:

Significant rainfall can be expected across much of Central, Northern, and Western New Mexico, and the Ruidoso area could also see some additional heavy downpours.

Utah and Northern Arizona:

Friday-Saturday rainfall will be heaviest across Eastern Utah, including the Moab region where flash flooding is a significant threat in slot canyons and dry washes. Zion will be on the western fringe of this moisture with more isolated activity, but heavy downpours couldn't be ruled out.

Isolated to scattered thunderstorms can also be expected in the northern ranges, including the Wasatch and Uintas, 

Forecast for Sun (Jun 23) to Mon (Jun 24):

Colorado, Utah, and Northern/Central New Mexico will see a decrease in thunderstorms, with activity becoming more isolated and favoring higher terrain. However, an uptick in activity is expected across Arizona, including the Grand Canyon, Flagstaff area, and Mogollon Rim, as well as the Black Mountains in Western New Mexico. 

The Cascades and Olympics in Washington will also see some light showers as a weak system moves across the Pacific Northwest.

Forecast for Tue (Jun 25) to Wed (Jun 26):

Daily rounds of isolated to scattered thunderstorms can be expected across the Four Corners states, and some of this activity will also expand westward into the Sierra Nevada Range. Most storms will produce brief/light rainfall, but localized downpours are possible under stronger storms, and of course, cloud-to-ground lightning is a threat with any thunderstorm.

Outlook for Thu (Jun 27) to Mon (Jul 1):

We will not see much change in the weather pattern during the final days of June. Above-average temperatures will continue across most of the West, while a low-grade monsoon will persist across the Southwest with near-daily rounds of thunderstorms.

A trough of low pressure over the Pacific Northwest will result in cooler temperatures with occasional showers for the Cascades and possibly the Northern Rockies.

Thanks so much for reading and have a great weekend! Next update on Monday (June 24).

Alan Smith