textproduct: NWS Flagstaff

SYNOPSIS

High pressure will build into the area through the weekend leading to hotter temperatures. Isolated to scattered showers and thunderstorms are expected today, with increasing coverage spreading westward starting Saturday and continuing through the middle of next week.

DISCUSSION

Strong high pressure will be centered just to our east into the middle of next week. This will lead to generally above normal temperatures, with the hottest days forecast today and Saturday. Monsoon moisture remains over the region, though PW values are a bit lower than we saw earlier in the week. There is still plenty of moisture for scattered high country storms and isolated activity at lower elevations today. Starting Saturday and continuing into early next week, additional moisture will arrive from southeast to northwest with increasing storm coverage, first along the rim and White Mtns Saturday and then spreading farther north and west each day. Again the main threat with storms will be elevated risk for locally heavy rainfall and flash flooding, especially since many areas have wet ground conditions. The Extreme Heat Warning continues for the lower elevations of Grand Canyon as well as Marble/Glen Canyons through Sunday. Lower elevation areas of Yavapai County will also see elevated HeatRisk, but the uncertainty of afternoon storms and associated rain- cooled air kept us from issuing a warning there. Temperatures next week should be a bit cooler, but areas that don't see as much storm activity will still be quite hot as the ridge will continue to be stronger than usual for late July.

AVIATION...Friday 24/12Z through Saturday 25/12Z

Mainly VFR expected. ISO-SCT SHRA/TSRA between 18Z-03Z. Brief MVFR/IFR conditions, gusty/erratic winds, and hail possible in stronger storms. Outside of storms, expect light and variable or terrain driven winds.

OUTLOOK...Saturday 25/12Z through Monday 27/12Z...Mainly VFR expected. ISO-SCT SHRA/TSRA, mainly between 18Z-03Z each day. Brief MVFR/IFR conditions, gusty/erratic winds, and hail possible in stronger storms. Outside of storms, expect light and variable or terrain driven winds.

FIRE WEATHER...Today through Saturday

Scattered afternoon and evening showers and thunderstorms are expected over the higher terrain, with only isolated activity at lower elevations. High temperatures warm to 5-10 degrees above average. Winds are generally light through the period outside of outflow and thunderstorm activity. Minimum RH's 15-30%.

Sunday through Tuesday...Monsoon moisture trends upward with scattered showers and thunderstorms. Temperatures 5-10 degrees above average Sunday trend back towards average Monday and Tuesday. Generally light winds outside of outflow and thunderstorm activity. Minimum RH 15-25% lower deserts to 30-45% higher terrain.

FGZ WATCHES/WARNINGS/ADVISORIES

Extreme Heat Warning from 10 AM MST /11 AM MDT/ this morning to 8 PM MST /9 PM MDT/ Sunday for AZZ005-006.