textproduct: NWS Flagstaff

SYNOPSIS

Seasonable temperatures will persist through the end of the week, before slightly cooler conditions return this weekend into next week. Isolated to scattered showers and thunderstorms today, with much drier conditions returning Friday onward. Critical fire weather conditions expected for Friday and the weekend and a Red Flag Warning is in effect.

DISCUSSION

Strong high pressure over northern Mexico today will gradually shift eastward as an unseasonably strong low pressure system moves into Pac NW and eventually the Great Basin/northern Rockies by Saturday and Sunday. Much above normal moisture levels will persist today, and scattered light showers have persisted overnight in east central Arizona with a stray shower as far west as Flagstaff. Storm redevelopment is expected after around 11 AM, mainly from the Mogollon Rim and White Mountains northward. While the main threat from storms will continue to be gusty outflow winds to 40-50 mph, MUCAPE values of 600-1100 J/kg may result in a few stronger storms with small hail and brief heavy downpours. Overall rainfall amounts will be light in most areas as storms will be moving off to the northeast at 20-25 mph. Most of the activity will decrease this evening though showers and storms could persist through late evening in northeast Arizona.

Friday through the weekend - the trough will slowly approach our region from the northwest, pushing moisture eastward and bringing a drying trend. Southwest winds will increase, with gusts 35-45 mph Friday then 40-55 mph Saturday. The gusty winds will persist overnight Saturday at the higher elevations and then increase again Sunday area wide. With the drier air moving in, a Red Flag Warning is in effect for all of northern Arizona from Friday through Sunday. The trough weakens but persists early next week just to our west, with lighter but still breezy winds and continued dry conditions. Daytime temperatures will be 5-10 degrees below normal Saturday through at least Tuesday.

AVIATION...Thursday 25/12Z through Friday 26/12Z

VFR conditions with isolated showers and thunderstorms this morning from the Mogollon Rim northward. Areas of haze or smoke are possible along the Arizona Utah border this morning, as well as around KSEZ from local fires. After 18Z, winds SW-W 10-20 kts with gusts 25-30 kts continuing through around 02Z. Brief MVFR visibilities associated with scattered thunderstorms after 18Z, mainly along/north of a KGCN-KFLG-KSOW line.

OUTLOOK...Friday 26/12Z through Sunday 28/12Z...Mainly VFR conditions. Drying out across most of the state Friday, but showers and thunderstorms are possible along the Arizona/New Mexico border. In addition, areas of haze/smoke are possible from local wildfires. Winds SW 15-25 kts with gusts 30-40 kts Friday, remaining elevated Friday night. On Saturday, widespread winds of SW 20-30 kts with gusts 35-45 kts. Gusty winds continue Saturday night, but strongest downwind of high terrain.

FIRE WEATHER...Today and Friday

Chance for showers and thunderstorms this afternoon and evening, mainly from the Mogollon Rim northward. Isolated showers or thunderstorms possible along the Arizona/New Mexico border Friday, drying out elsewhere. A Red Flag Warning is in effect for all of northern Arizona Friday due to increasing winds and decreasing humidity. Winds SW 10-20 mph gusting to 25-30 mph today, then SW 20-30 mph gusting to 35-45 mph Friday. Minimum afternoon RH 20-30% today, 8-20% Friday. Saturday through Monday...The Red Flag Warning continues Saturday and Sunday for strong winds and low humidity. Winds SW 20-30 mph with gusts 40-55 mph on Saturday, continuing through the night at the higher elevations. Winds Sunday SW 20-30 mph with gusts 35-45 mph, dropping to SW 10-20 mph with gusts around 30 mph on Monday. Minimum afternoon RH values each day as low as 7-10% lower elevations to 12-20% Mogollon Rim and White Mountains.

FGZ WATCHES/WARNINGS/ADVISORIES

Red Flag Warning from 11 AM MST /noon MDT/ Friday to 8 PM MST /9 PM MDT/ Sunday for AZZ104>118-137>140.