textproduct: NWS Flagstaff

SYNOPSIS

Windy and cooler weather will move in over the weekend. Southwest winds peak on Sunday with areas of critical fire weather conditions likely. The pattern remains unsettled heading into next week.

DISCUSSION

A series of shortwave troughs will brush Arizona into next week delivering breezy to windy conditions at times along with cooler daytime temperatures. Critical fire weather conditions are expected for portions of northern Arizona over the weekend.

Over the weekend...The strongest in the series of shortwave troughs will move across northern Arizona. The first will be well timed for daytime Saturday with the second shortwave Sunday afternoon and night. The main impact of these systems will be a wide area of southwest winds at 15-25 mph gusting to 30-40 mph on Saturday then increasing to 15-30 mph gusting to 40-50 mph on Sunday. The higher wind/gust values in the ranges shown will primarily be located from the Mogollon Rim northward. In addition, afternoon relative humidity values will range from 10-20% across the area. The combination of wind and dry conditions will result in near-critical to critical fire weather conditions across northern Arizona. As a result, a Red Flag Warning is in effect for potions of the area both Saturday and Sunday. The system will be mainly dry but a few stray light showers near the Arizona/Utah border can't be ruled out on Sunday.

For Monday and Tuesday...A weaker pair of shortwave troughs will brush the area, one by late Monday and another late Tuesday. The main impact of these two systems will be to keep daytime temperatures a bit below normal. Daytime west to southwest breezes will continue but much reduced compared to the weekend.

From Wednesday onward...It appears the last in the series of shortwave troughs will head eastward to be replaced by a weak high pressure system. At this time the end of next week is set to see warming daytime temperatures and a continuation of the usual afternoon breezes.

AVIATION...Saturday 16/00Z through Sunday 17/00Z

VFR conditions. Winds S 5-10 kts overnight, becoming S/SW 15-20 kts with gusts 25-35 kts after 16Z.

OUTLOOK...Sunday 17/00Z through Tuesday 19/00Z...VFR conditions, outside of brief periods of MVFR in ISO -SHRA/-SHSN near the AZ/UT border 00Z-12Z Monday. Winds S/SW 20-25 kts with gusts 35-40 kts on Sunday, becoming SW-NW 10-20 kts with gusts 25-35 kts on Monday.

FIRE WEATHER...Saturday and Sunday

Dry with temperatures 5-10 degrees above average Saturday, but cooling down close to average on Sunday. A slight chance of showers is possible Sunday night into early Monday morning along the Arizona/Utah border. Winds SW 15-25 mph, gusts 35-40 mph on Saturday, increasing to SW 20-30 mph, gusts 40-45 mph on Sunday. Minimum RH values 10-20% Saturday, 10-25% Sunday. Areas of critical fire weather conditions are forecast for both Saturday and Sunday afternoons and Red Flag Warnings have been issued for those locations.

Monday through Wednesday.... Temperatures remain cool on Monday and Tuesday at 5 to 10 degrees below average before recovering closer to average on Wednesday. Winds W-NE 10-20 mph, gusts 30-35 mph on Monday, SW-W 10-20 mph on Tuesday and Wednesday. Minimum RH values 10-20% Monday, 8-15% Tuesday and Wednesday.

FGZ WATCHES/WARNINGS/ADVISORIES

Red Flag Warning from 11 AM MST /noon MDT/ to 8 PM MST /9 PM MDT/ Sunday for AZZ104>106-109>114-116-117-139-140.

Red Flag Warning from 11 AM MST /noon MDT/ to 8 PM MST /9 PM MDT/ Saturday for AZZ107>109-112>116-139-140.