textproduct: NWS Flagstaff

SYNOPSIS

Warm 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 today with drier air arriving on Friday.

DISCUSSION

High pressure across the region continues to bring some drier air into the region but moisture is slow to leave and this has resulted in daily diurnally driven showers and thunderstorms. PWATs will gradually drop but there looks to be a a little bit of a moisture surge today, which will be the catalyst for some showers and storms to develop. Main areas will be along the Mogollon Rim through the White Mountains, but hi-res models continue to have some showers/storms developing to along the I-40 corridor and in Yavapai County. One limiting factor today may be the debris clouds that are across the region early this morning, which will keep the surface from heating up and allowing for destabilization to occur. Should the clouds dissipate in time, we may see some stronger storms develop through this afternoon and into early this evening. Gusty winds, heavy rainfall, and small hail will be possible in stronger storms.

With the drier conditions across northern areas and increasing daytime temperatures, areas below 4000 feet in the Grand Canyon will once again reach between 103-112 degrees today. An Extreme Heat Warning remains in effect through this evening. 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 across the Desert Southwest will continue to result in breezy southwest winds across our area through the end of the week. While most areas will 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. A few isolated showers may occur on Friday over the White Mountains, but the rest of the region look so dry out enough that any chance for showers will end. Gradients don't look overly tight with this trough but expect afternoon breezes to continue through the region. A building ridge into early next week may allow for some moisture to briefly nudge back into the region towards Tue/Wed but confidence in chances for showers or thunderstorms is pretty low at this time.

AVIATION...Thursday 18/18Z through Friday 19/18Z

Mainly VFR conditions. Isolated SHRA/TSRA along and south of a KGCN-KFLG-KSOW line through 02Z. Erratic, gusty winds of 30-40 kts in and near TSRA. Winds S to SW 10-20 kts gusting 25-30 kts through 03Z. Generally light winds overnight except remain gusty just northeast of terrain features.

OUTLOOK...Friday 19/18Z through Sunday 21/18Z...VFR conditions. Winds S to SW 10-20 kts with gusts 25-30 kts each day. Overnight winds genrally light except remaining elevated just northeast of terrain features.

FIRE WEATHER...Today and Friday

Warm temperatures and mostly dry conditions expected. Isolated showers and thunderstorms through early evening, mainly along the Mogollon Rim through the White Mountains. Localized downpours and wind gusts to 40 mph are possible with any thunderstorms. Isolated showers and thunderstorms near the White Mountains on Friday. Away from storms, west to southwest winds at 10-20 mph with gusts 20-30 mph, becoming southwest on Friday. 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.

Saturday through Monday...Dry, breezy, and warm weather continues into next week. Southwesterly winds at 10-20 mph with gusts to 25-30 mph Saturday, decreasing to 10-15 mph with gusts to 20-25 mph on Sunday and Monday. 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 this evening for AZZ006.