textproduct: NWS Flagstaff

SYNOPSIS

Windy and dry weather will result in critical fire weather conditions across portions of northern Arizona this weekend. Then, chances for showers increase along and north of Interstate 40 from Sunday night into Monday. Cool, dry and breezy conditions are forecast on Monday and Tuesday, before quiet weather and near normal daytime temperatures overtake the area from Wednesday through the remainder of the work week.

DISCUSSION

The first in a series of shortwave troughs was producing a wide area of southwest winds at 15-25 mph gusting to 30-40 mph across northern Arizona Saturday afternoon. This in combination with relative humidity values ranging from 10-20% was producing a widespread area of elevated fire danger. As a result, a Red Flag Warning remains in effect across much of northern Arizona into this evening. The current shortwave will exit the state overnight.

On Sunday...A stronger shortwave trough will move across the area. Look for southwest winds at 15-30 mph gusting to 40-50 mph. The higher wind/gust values in the ranges shown will primarily be located from the Mogollon Rim northward and across the higher elevations of Yavapai County with a Wind Advisory in effect for those areas. Gusty winds will likely then linger through Sunday night. In addition, afternoon relative humidity values will once again range from 10-20% across the area. The combination of strong winds and dry conditions will result in another round of near- critical to critical fire weather conditions. As a result, a Red Flag Warning is in effect for portions of northern Arizona again on Sunday but with such strong winds, fire danger will be elevated across the area. The trough will be mainly dry but Sunday night a few light showers (snow showers over the highest elevations of the Kaibab Plateau) toward the Arizona/Utah border can't be ruled out as the cold core of the trough moves through.

For Monday and Tuesday...Shower chances exit the state early Monday. Otherwise, weak troughing will linger over Arizona. The main impact will be to keep daytime temperatures a bit below normal. Look for southwest to west breezes on Monday at 10-20 mph with gusts to over 30 mph from Flagstaff eastward. Tuesday will see lighter winds generally from the west to northwest at 10-20 mph.

From Wednesday onward...The trough weakens further, potentially being replace by a weak high pressure system by next weekend. Look for daytime highs to climb to a bit above average with typical afternoon breezes of 10-20 mph each day.

AVIATION...Sunday 17/00Z through Monday 18/00Z

VFR conditions. S-SW winds 15-25 kts with gusts to 35 kts through 03Z, then becoming SW 5-15 kts overnight. Winds increase to 15-25 kts with gusts to 30-40 kts after 15Z.

OUTLOOK...Monday 18/00Z through Wednesday 20/00Z...Mainly VFR conditions. ISO -SHRA/-SHSN mainly north of KGCN-KRQE line 00Z-18Z Monday. SW-NW winds 10-20 kts with gusts 25-35 kts on Monday, becoming NW-N 10-20 kts on Tuesday.

FIRE WEATHER...Sunday and Monday

A Red Flag Warning is in effect Sunday for most of northeastern Arizona, mainly areas northeast of the Mogollon Rim. A trough moving into the area will drop temperatures close to seasonal averages on Sunday and about 5 to 10 degrees below average on Monday. A few rain and high elevation snow showers are possible north of the Interstate 40 corridor Sunday night into Monday morning, but wetting rains are not expected. Winds S-SW 20-30 mph, gusts 45-50 mph Sunday, W-NW 10-20 mph, gusts 25-35 mph Monday. Minimum RH values 10-25% Sunday, 15-30% Monday.

Tuesday through Thursday....Temperatures remain cool on Tuesday at 5 to 10 degrees below average before recovering closer to average on Wednesday and Thursday. Winds SW-W 10-20 mph each day. Minimum RH values 8-15% each day.

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.

Wind Advisory from 11 AM MST /noon MDT/ to 8 PM MST /9 PM MDT/ Sunday for AZZ004-006>009-011>017-038>040.

Red Flag Warning until 8 PM MST /9 PM MDT/ this evening for AZZ107>109-112>116-139-140.