textproduct: NWS Flagstaff

SYNOPSIS

Warm temperatures and mainly dry weather will continue through the weekend. Isolated to scattered high-based showers and thunderstorms are forecast over the higher terrain on Monday. Expect typical southwest breezes each afternoon, with increasing winds and cooler temperatures arriving around midweek.

DISCUSSION

For the remainder of today, expect partly to mostly cloudy skies associated with a passing, dry frontal boundary. Otherwise, near normal temperatures with light west to southwest wind gusts are forecast for this afternoon.

For the weekend, high pressure strengthens over the area bringing slightly warmer temperatures and a continuation of light daytime winds. Surface moisture does increase, which will aid cumulus development in mountainous areas, but a stout mid-level inversion should cap growth resulting in fairly shallow clouds and rain that evaporates before hitting the ground. The inversion does weaken a bit on Sunday, bringing a low (5% to 15%) chance of light rain showers over the mountains.

On Monday, better chances for showers are forecast due to a passing low-pressure system. The current forecast is calling for a 40-70% chance for precipitation from the Mogollon Rim northward. In general, precipitation amounts are expected to be on the lighter side, with model totals ranging from a trace to as high as 0.3 inches. Winds are too light and humidity is too high for critical fire weather concerns, but isolated thunderstorms may result in new starts and gusty outflow winds in the periphery of the storms.

On Tuesday, a few lingering showers and thunderstorms are possible in Apache County as the low exits the area. Otherwise, look for partly cloudy skies and near normal temperatures. After Wednesday, model spread increases significantly regarding the broad-scale weather pattern. In general, model solutions show another low impacting the western United States, but the location, track, and intensity vary significantly. Few model solutions show meaningful precipitation middle to late next week, but there is better model agreement regarding increasing wind speeds. Current model data shows about a 1 in 2 chance (50% probability) that parts of northern Arizona will experience critical fire weather conditions on Tuesday and/or Wednesday.

AVIATION...Friday 22/18Z through Saturday 23/18Z

VFR conditions are expected. Winds SW to W at 5-15 kts gusting to 20-25 kts, then diminishing to light and variable after 02Z.

OUTLOOK...Saturday 23/18Z through Monday 25/18Z...VFR conditions are forecast. Isolated virga showers and associated gusty/erratic winds possible south of a KSOW-KSJN line Sunday afternoon. Otherwise, winds SW to W at 5-15 kts gusting to 20-25 kts each day.

FIRE WEATHER...Saturday and Sunday

Dry and warmer. Look for west to southwest winds at 10-20 mph. Minimum afternoon RH between 5-15% on Saturday increasing to 10-20% on Sunday.

Monday through Wednesday....Expect a further increase in moisture Monday with a passing weather disturbance. As a result, isolated to scattered showers and thunderstorms are forecast across much of northern Arizona. Dry lightning and erratic outflow gusts will be possible. Outside of storms, expect southwest winds at 10-20 mph on Monday. A drier air mass is expected to move in for Tuesday and Wednesday. In addition, look for southwest winds at 10-20 mph gusting to 30 mph on Tuesday, then increasing to 15-25 mph gusting to 35 mph Wednesday.

FGZ WATCHES/WARNINGS/ADVISORIES

None.