textproduct: NWS Flagstaff

SYNOPSIS

High pressure continues to dominate the Southwest. This synoptic pattern will make way for increased monsoon activity today, and even more so for next week. Outside of increased chances for showers/storms, extreme heat will continue through at least Friday.

DISCUSSION

Monsoon activity looks to ramp up this afternoon/evening, especially for locations across the Mogollon Rim. The recent U of A WRF run shows activity initiating over the Peaks and White Mountains around noon today and gradually pushing westward through the rest of the afternoon/evening hours. Forecast soundings show plenty of instability and decent shear, so we could see a handful of severe storms similar to yesterday. Not only that, but localized flooding could also be a concern from training storms.

A more favorable monsoon pattern will set-up later this weekend/into next week, as the area of high pressure is projected to settle over the Four Corners. Prior to the incoming active monsoon days, we could see a brief downward trend in convective activity Friday and Saturday. The NBM still has chances for showers/storms across the higher elevation locations, but we are not anticipating more widespread activity until Sunday onward.

Outside of precipitation, heat will continue to be a concern for a handful of locations. The Extreme Heat Warning remains in place for the lower elevations of the Grand Canyon and Marble/Glen Canyons through Friday evening, but there is potential for this to be extended through the weekend. Regardless, temperatures will be above normal for this time of year, so minimize outdoor activity during the middle of the afternoon and stay hydrated!

AVIATION...Thursday 06/06Z through Friday 07/06Z

Mainly VFR conditions. Isolated -SHRA/-TSRA through 18Z then becoming scattered mainly along and south of a KGCN-KFLG-KSOW line. Gusty and erratic winds and MVFR/IFR conditions possible with storms. Otherwise, winds southwest to west 5-15 kts daytime, light and variable overnight.

OUTLOOK...Friday 07/06Z through Sunday 09/06Z...Mainly VFR conditions. Look for SHRA/TSRA each day, most numerous between 18Z-03Z. Gusty and erratic winds and MVFR/IFR conditions possible with storms. Otherwise, winds southwest to west at 5-15 kts daytime, light and variable overnight.

FIRE WEATHER...Thursday and Friday

Above normal temperatures forecast to continue, along with daily chances for showers/thunderstorms. Greatest coverage will be across the higher terrain each afternoon/evening. Main concerns with stronger storms will be heavy rain, small hail, frequent lightning, and gusty/erratic winds. Outside of storm driven winds, look for variable winds around 5-15 mph.

Saturday through Monday...Daytime highs will gradually cool through the weekend/into next week, but still remain a few degrees above normal. Isolated showers/thunderstorms forecast for Saturday, before ramping up in coverage Sunday onward. Gusty/erratic winds possible from showers/storms, otherwise expect variable winds 5-15 mph.

FGZ WATCHES/WARNINGS/ADVISORIES

Extreme Heat Warning until 8 PM MST /9 PM MDT/ Friday for AZZ005- 006.