textproduct: NWS Flagstaff

SYNOPSIS

Warmer temperatures, mostly dry conditions, and breezy afternoon winds are expected through the rest of the week. Isolated chances for showers or thunderstorms continue across the higher terrain through Thursday.

DISCUSSION

High pressure across the region has allowed for some drying to occur but moisture remains trapped under the high. This will continue to bring chances for diurnally driven showers and thunderstorms, generally along and south of the higher terrain. As the high sinks to the south, the moisture will eventually follow with drier air taking its place. Expect Thursday to remain similar to today before the dry air wins out.

With the drier conditions across northern areas and increasing daytime temperatures, areas below 4000 feet in the Grand Canyon will again reach between 103-112 degrees today and Thursday. An Extreme Heat Warning remains in effect through Thursday. If you have plans to be in the canyon, then make sure you are prepared for very hot conditions and try to avoid hiking during the day.

Interaction between the long wave trough across much of the United States and the ridging that is building across the Desert Southwest will result in breezy southwest winds across our area through the end of the week. While most areas will decouple and see lighter winds at night, winds will continue to remain elevated through the overnight hours for areas downwind of terrain features.

Drier conditions along with the expected stronger winds across the region, will bring near-critical fire weather conditions through the rest of the week, mainly to far northern and eastern Arizona.

Heading into the weekend, a trough will approach the area, which will bring drier air and should help to cool temperatures slightly. Gradients don't look overly tight with this trough but expect afternoon breezes to continue through the region.

AVIATION...Wednesday 17/12Z through Thursday 18/12Z

Mainly VFR conditions with brief MVFR in ISO-SCT -SHRA/-TSRA after 18Z, mainly along/south of a KFLG-KINW-KSJN line. Erratic gusts 30-40 kts INVOF TSRA. Outside of storms, W-SW winds 15-20 kts with gusts 25-30 kts after 18Z, becoming light 5-15 kts overnight. Overnight winds remain elevated downwind of the terrain features.

OUTLOOK...Thursday 18/12Z through Saturday 20/12Z...Mainly VFR conditions. ISO-SCT -SHRA/-TSRA between 18Z-00Z Thursday, mainly along/south of a KFLG-KSJN line. SW-W winds 10-20 kts with gusts 25-30 kts each day. Overnight winds remain elevated downwind of the terrain features.

FIRE WEATHER...Today and Thursday

Warm temperatures and mostly dry conditions expected. Isolated showers and thunderstorms in the afternoons, mainly along the Mogollon Rim and over the White Mountains. Localized downpours and wind gusts to 40 mph possible with any thunderstorms. Outside of storms, expect west to northwest winds at 15-25 mph with gusts to 25-35 mph today, then shifting to west to southwest at 10-20 mph with gusts 20-30 mph on Thursday. Winds remain elevated each night downwind of terrain features. Minimum RH around 10-20% each day. Near-critical fire weather conditions possible across far northern and eastern Arizona each day.

Friday through Sunday...Dry, breezy, and slightly cooler weather expected. Southwesterly winds at 10-20 mph with gusts to 25-30 mph Friday and Saturday, decreasing on Sunday to around 10-15 mph. Minimum RH drops to 5-15% each afternoon. Near-critical fire weather conditions possible across northeast Arizona each day.

FGZ WATCHES/WARNINGS/ADVISORIES

Extreme Heat Warning until 8 PM MST Thursday for AZZ006.