textproduct: NWS Flagstaff

SYNOPSIS

Look for isolated showers and thunderstorms from the White Mountains and Mogollon Rim southward again Thursday. Widespread shower and thunderstorm activity could develop by Friday and Friday night with a passing weather disturbance. Temperatures will remain above normal through Thursday, then cooling off over the weekend. Chances for showers and thunderstorms will continue into next week.

DISCUSSION

High pressure was centered over the California/Arizona border early morning Thursday. In this position flow around the high will deliver drier air from the west to northwest. Limited monsoon moisture will continue to linger along and south of the Mogollon Rim and White Mountains with just slight chances for a stray shower or thunderstorm. Further north, the drier air will win out resulting in fair and breezy conditions. Under high pressure temperatures will remain on the hot side with mountain highs ranging from the upper 70s to mid 80s and 95 to 105 at lower elevations.

For Friday and the weekend..A trough will dive across the Pacific Northwest pushing the California/Arizona high center eastward. As the shifting trough brushes Arizona the models continue to show decent coverage of showers and thunderstorms Friday and Friday night. Vertical wind shear will strengthen some with the passing trough which usually means a few storms will become organized with isolated severe thunderstorms and localized flash flooding possible. The trough moves eastward on Saturday and Sunday but monsoon moisture will linger with at least slight chances for showers and thunderstorms continuing. Under the influence of the trough it will become breezy with general west to southwest winds at 10-20 mph gusting to 25-30 mph starting Friday and lasting through the weekend. Cooler with temperature dropping to slightly above seasonal average by Sunday.

Looking into next week...Troughing will continue over the Pacific Northwest early next week with a series of weak shortwave troughs brushing Arizona and interacting with monsoon moisture. While it is difficult to predict exactly how things will pan out it appears that unsettled conditions will continue with at least slight chances for daily showers and thunderstorms. Models still showing a stronger low diving southward off the west coast later next week turning the flow more southerly over Arizona resulting in perhaps better chances for showers and storms.

AVIATION...Thursday 10/18Z through Friday 11/18Z

Expect VFR conditions. ISOLD -SHRA/-TSRA possible through 02Z Friday, primarily south of the I-40 corridor. Daytime sfc winds W-NW5-15kts.

OUTLOOK...Friday 11/18Z through Sunday 13/18Z...Expect mainly VFR conditions. ISOLD-SCT -SHRA/-TSRA each afternoon/early evening. Daytime sfc winds W-10-20kts.

FIRE WEATHER...Today and Friday

Isolated showers and storms will be possible along and south of the Mogollon Rim today, becoming scattered on Friday across much of northern Arizona. Winds ranging from west to northwest 5-15 mph today, becoming west to southwest 10- 20 mph on Friday.

Saturday through Monday...Chances for isolated to scattered showers and thunderstorms remain through the weekend into Monday, mainly over the higher terrain. Winds southwest 10-20 mph on Saturday, increasing to 15-25 mph gusting 30-35 mph on Sunday, then subsiding to 10-20 mph for Monday.

FGZ WATCHES/WARNINGS/ADVISORIES

None.