textproduct: NWS Flagstaff

SYNOPSIS

Dry conditions are expected, with seasonable temperatures and occasionally breezy conditions, mainly along the Mogollon Rim and other higher terrain features.

DISCUSSION

The weak, 500 mb cut-off low is currently located over west-central AZ and will continue to shift southward through the evening, and exiting AZ by Saturday morning. This is supporting scattered showers and a few embedded thunderstorms, mainly across Navajo and Apache counties, where southeast to southwest 850-500 mb winds have allowed for transport of moisture in the region. A a couple isolated showers and thunderstorms are also starting to develop to the west of Flagstaff, near and south of Williams and Ash Fork, where instability is starting to increase due colder air aloft, positive vorticity advection and upper-level divergence just south of the 500 mb low starting to increase the instability in the area. As the 500 mb low continues to shift southward, the development of showers and thunderstorms will also shift southward. Rainfall amounts are expected to remain light and generally around 0.10" to 0.20", with a few locally higher amounts between 0.25" to 0.70" in heavier showers and thunderstorms. As the low shifts south, colder air will be drawn down to the surface and some snow may begin to mix in. Snow levels look to be mostly near or above 8000', including areas like Buffalo Pass in the Chuskas, with little to no accumulation expected.

For Saturday and Sunday, as the 500 mb low continues to move south of AZ through the weekend, the pressure gradient will strengthen, creating breezy conditions, especially across the higher terrain. Winds will be out of the north to northeast around 5-15 mph in most areas with gusts to 20-35 mph along and south/southwest of the higher terrain.

Monday through Thursday, a mostly dry and mild weather pattern is expected. A weak short-wave trough is expected to cross through southern Arizona on Tuesday, but moisture will be very limited and is unlikely that more than an isolated shower or two will develop, mainly near the White Mountains. Looking further into the weekend, ensemble models continue to show a deepening west coast trough that becomes a cut-off low as it moves over the United States. Most models continue to favor a souther track, keeping the low sufficiently south to limit moisture returns into the region. However, a shift northward could bring another round of showers to our area.

AVIATION...Saturday 07/06Z through Sunday 08/06Z

Patchy MVFR due to low clouds and fog along the north/northeast side of the Mogollon Rim through 08Z, otherwise VFR. Sfc winds E-NE10-20kts, generally stronger in the daytime and over higher terrain.

OUTLOOK...Sunday 08/06Z through Tuesday 10/06Z...Expect VFR conditions. Sfc winds E-NE5-15g20kts.

FIRE WEATHER...This afternoon through Sunday

Scattered showers with a few embedded thunderstorms will continue into this evening, especially over eastern Arizona, dissipating by late tonight. Some showers will change over to snow above 8000-9000 feet, but little to no accumulations are expected. Dry weather returns for Saturday and Sunday. North to northeast winds 5-15 mph with gusts to 30 mph through this evening, then increasing to 10-20 mph with gusts to 25- 35 mph on Saturday and Sunday.

Monday through Wednesday...Expect dry conditions and seasonable temperatures to continue. Light and variable winds on Monday and Tuesday, becoming north to northeast 5-15 mph on Wednesday. Minimum RH's 30-45% each day.

FGZ WATCHES/WARNINGS/ADVISORIES

None.