textproduct: NWS Flagstaff

SYNOPSIS

A chance of showers and thunderstorms moves in across the area Tuesday with a few showers lingering over the northeastern corner of the state into Wednesday. Fair and warmer weather returns for Thursday and the weekend.

DISCUSSION

An upper level low over California is drawing in a plume of moisture in the form of mid and high level clouds over the state at this time. A few light showers will move into southeastern Arizona this afternoon with this plume, before being drawn further northward into the White Mountains tonight and to most of northern Arizona Tuesday as the low makes its way through. As the cold core of the low moves through, there'll be enough instability for a few thunderstorms. High temperatures with the cloud cover and colder air will be about 10 degrees below average Tuesday before recovering to near average as the system begins to move east Wednesday. Snow levels will be high with this system, but a few snowflakes may mix in tomorrow morning above 7000ft with no accumulation expected outside of the highest part of the peaks. Rainfall amounts will be below a tenth of an inch in the high deserts to between a tenth and quarter inch along the Mogollon Rim, White Mountains and Chuskas. Winds will be a little lighter tomorrow versus today as the pressure gradient decreases as the system passes through.

A few lingering showers are possible in the northeast corner of Arizona as the system pulls away. By Thursday high pressure begins rebuilding into the region and high temperatures go up considerably to about 10 degrees above average by the weekend. Minimum relative humidity values will be quite low in the 7-15% range which will quickly dry out any gains we got from Tuesday's system. The saving grace will be the winds at this time look to be in the 5-15 mph range so that should keep us out of critical fire weather for now.

AVIATION...Monday 04/18Z through Tuesday 05/18Z

VFR conditions, with MVFR moving in overnight over the higher terrain, and brief IFR possible in higher terrain between 12Z-18Z Tuesday. Chance of showers moves in after 00Z into the White Mountains, spreading westward as the night and morning progresses. Snow may mix in at times between 12-18Z at KFLG. Winds S-SW 15-25kts, gusts 30-35kts daytime, diminishing a little overnight but still SW 10-20kts, gusts 25-30kts.

OUTLOOK...Tuesday 05/18Z through Thursday 07/18Z...VFR-MVFR through 06Z Wed. Scattered showers and thunderstorms across most of northern Arizona through 06Z Wed. Then shower and thunderstorm chances focus over the northeastern corner of Arizona 06Z Wed through 00Z Thursday. Winds SW 10-20kts, gusts to 30kts Tuesday. Then NW 10-20kts Wednesday.

FIRE WEATHER...Tuesday and Wednesday

Expect scattered showers and isolated thunderstorms on Tuesday over most of northern Arizona. Shower and thunderstorm chances become confined to the northeastern corner of the state Wednesday. Rainfall amounts will generally be light although some areas over the Mogollon Rim and White Mountains could see a wetting rain. Winds SW 10-20 mph gusting to 30 mph on Tuesday, becoming NW 5-15 mph on Wednesday. Minimum RH values 25-50% on Tuesday, dropping to 15-30% Wednesday.

Thursday through Saturday...Dry conditions with temperatures warming to 10 degrees above average by the weekend. Winds NW-N 5-10 mph Thursday, NW 5-15 mph Friday, W-NW 10-20 mph on Saturday. Minimum RH values 8-15% each day.

FGZ WATCHES/WARNINGS/ADVISORIES

None.