textproduct: NWS Flagstaff

SYNOPSIS

Warm temperatures continue with isolated to scattered showers and thunderstorms through the weekend, Cooler temperatures and more widespread showers and thunderstorms are expected next week.

DISCUSSION

High pressure will remain the main feature of the forecast as it weakens and pushes to the north over the weekend. By early next week, the high will slide over the Four Corners region.

For today, expect similar conditions to the past few days with isolated to scattered showers and thunderstorms. Storms will initiate across the higher terrain by early afternoon, moving off towards the south and west through this evening. Instability remains marginal so can't rule out a few strong to severe storms, mainly over Yavapai and Gila counties. Heavy rain with the potential for flash flooding will remain the main hazard.

Today should be the end of the very hot temperatures we have seen up in the Grand Canyon and Glen/Marble Canyons for the past week or so. With increasing moisture, storm coverage, and cloud cover, the heat will finally break, allowing for the Extreme Heat Warning to finally expire this evening.

The active monsoon pattern will hold through next week as the high remains near or over the Four Corners region. Temperatures will cool across the region and will see scattered to numerous showers and thunderstorms each day. Overall, expect the monsoon to become the main story for the next week.

AVIATION...Saturday 08/12Z through Sunday 09/12Z

Expect mainly VFR conditions outside of thunderstorms. ISO-SCT SHRA/TSRA between 19Z-03Z, mainly along and west of a KGCN-KFLG-KSJN line. Some storms will produce brief MVFR/IFR and wind gusts to 40 kts. Outside of storms, expect SW-W winds 5-15 kts.

OUTLOOK...Sunday 09/12Z through Tuesday 11/12Z...Expect mainly VFR conditions outside of thunderstorms. SCT-NMRS SHRA/TSRA from 18Z-03Z each day, especially along and near the Mogollon Rim and White Mtns. Some storms will produce brief MVFR/IFR and wind gusts to 40 kts. Outside of storms, expect SW-W winds 5-15 kts.

FIRE WEATHER...Today and Sunday

Above normal temperatures with isolated to scattered showers and thunderstorms each day, greatest coverage across the higher terrain and areas to the south and west each afternoon/evening. Stronger storms may contain heavy rain, small hail, frequent lightning, and gusty/erratic winds. Outside of storms, expect variable winds around 5-15 mph. Minimum RH values 5- 15% across NE Arizona, 20-40% elsewhere.

Monday through Wednesday...Near to slightly below normal temperatures with scattered to widespread showers and thunderstorms each day. Stronger storms may contain heavy rain, small hail, frequent lightning, and gusty/erratic winds. Outside of storms, expect variable winds around 5-15 mph. Minimum RH values 15-30% across NE Arizona, 30-60% elsewhere.

FGZ WATCHES/WARNINGS/ADVISORIES

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