textproduct: NWS Flagstaff

SYNOPSIS

Expect mainly dry and seasonably warm conditions to continue through much of the coming week. Slight chances for showers and thunderstorms develop for Tuesday through Thursday, mainly over the higher terrain.

DISCUSSION

Through Friday, High pressure aloft will dominate the weather across northern Arizona. Surface pressure gradients will favor northeast to southeast flow at 5 to 15 mph through Thursday, mainly during the daytime hours. Nighttime winds will be mainly light and variable. Winds shifting to light from the south on Friday. We're not anticipating much change in high and low temperatures as the high center meanders over the southwest United States. A very weak shortwave trough will brush the northeast corner of the state from Tuesday into Thursday which will introduce a bit cooler air aloft. The main impact will be that the combination of lingering monsoon moisture and daytime heating will act to produce some weak instability. The result will be isolated afternoon and early evening showers and thunderstorms over the higher terrain from the Mogollon Rim and White Mountains northward.

On Saturday...A low pressure system from over the Pacific will approach the western United States. The initial influence of the trough will be cooler daytime temperatures and strengthening southwest winds. There will be just enough moisture for a slight chance of showers or a stray thunderstorm over the mountains.

From Sunday into Tuesday or Wednesday...The operational GFS and ECMWF forecast models and associated ensemble members have locked on to a low of decent strength moving across the western states. By Sunday and heading into early next week this low could tap into tropical moisture, portions of which will be the dissipating remnants of once hurricane Rachael. The main difference in the current model package is that some solutions take the low center across the Pacific Northwest and northern Nevada. Other solutions drive the low center much further south with the center of the low moving across southern Nevada and northwest Arizona. As might be guessed the further southward the low center moves the higher the precipitation amounts across Arizona are likely to be. In either case, much cooler temperatures and gusty southwest winds are nearly certain. It is a bit early to get too excited about precipitation and much could change (this is the desert after all) but definitely something worth keeping an eye on.

AVIATION...Tuesday 06/06Z through Wednesday 07/06Z

Expect VFR conditions. Very isolated showers possible along the higher terrain by Tuesday afternoon. Winds generally light and VRB through the period.

OUTLOOK...Wednesday 07/06Z through Friday 09/06Z...Expect VFR conditions. ISOLD -SHRA/-TSRA possible each afternoon/evening over the higher terrain. Winds are light through the period, generally trending NE-E during the daytime.

FIRE WEATHER...Tuesday and Wednesday

Expect mainly dry conditions with seasonably warm temperatures. A slight chance of high-based showers or thunderstorms is possible over the White and Chuska Mountains Tuesday afternoon, but chances for wetting rains are near zero. Daytime winds light and variable at 5-15 mph on Tuesday, NE-E 5-15 mph Wednesday.

Thursday through Saturday... Slight chance of high-based showers or thunderstorms are possible Thursday over the White Mountains, dry on Friday area wide, then a slight chance of showers and thunderstorm over the higher terrain on Saturday. Chances for wetting rains are very low. Daytime winds Thursday NE-SE 5-15 mph, SE-S 5-15 mph on Friday, S-SW 5-15 mph on Saturday.

FGZ WATCHES/WARNINGS/ADVISORIES

None.