textproduct: NWS Flagstaff

SYNOPSIS

Dry weather and seasonably mild temperatures will continue through Thursday, with the potential for precipitation starting Friday and lasting through the weekend. Winds will mainly be north to northeast through Thursday with occasional breezy conditions, mainly along and south of higher terrain. Cooler temperatures and gusty southwest winds arrive on Friday and over the weekend.

DISCUSSION

High pressure aloft over the southwest United States will be the primary influence on northern Arizona weather through Thursday. Look for dry conditions, with mild daytime temperatures running from 5 to 10 degrees above average. Low temperatures will be near average due to the effects of a dry air mass, mainly clear skies and strong radiational cooling. Surface pressure gradients will favor generally light northeast of east winds at 5-15 mph.

For Friday and the weekend...A pair of weak shortwave troughs will produce chances for showers starting Friday, lasting through the weekend. The first shortwave will brush southern and southeast Arizona with chances for showers across the eastern Mogollon Rim, White Mountains and Chuska Mountains from Friday afternoon into Saturday (where the best combination of upward motion and moisture will reside). We're looking at trace to 0.10 inch accumulations with the first shortwave. The second shortwave rapidly follows and brushes the northern half of Arizona. Slight chances for showers will spread across all of northern Arizona with the second shortwave as additional upward motion moves across the state. Precipitation amounts of trace-0.20 inches are forecast with this second shortwave. Snow levels are expected to remain above 8,500 feet with these two relatively mild systems. Otherwise, look for cooler daytime temperatures and partly cloudy to mostly cloudy skies. Winds becoming south to southwest 5-15 mph gusting to 20-25 mph with the approach and arrival of the second shortwave.

Heading into next week...Unsettled weather will continue as the storm track remains in place. There is the potential for stronger and colder systems next week. The current best guess on timing for the first of these stronger systems is next Monday into Tuesday. We'll keep you posted as our confidence builds on the timing and finer details.

AVIATION...Monday 09/18Z through Tuesday 10/18Z

VFR with light and variable winds. Locally terrain driven winds overnight.

OUTLOOK...Tuesday 10/18Z through Thursday 12/18Z...VFR with light and variable winds. Locally terrain driven winds overnight.

FIRE WEATHER...Tuesday and Wednesday

Dry conditions and mild temperatures will continue. Expect light north through east winds 5-15 mph with minimum RH around 25-40% each day.

Thursday through Saturday...Mild temperatures and dry conditions through Thursday. Isolated rain showers on Friday near the White Mountains, then becoming scattered across the entire region on Saturday. Expect light north to northeast winds 5-15 mph on Thursday, becoming east to southeast 5-15 mph on Friday, then south to southwest 10-20 mph on Saturday. Minimum RH around 25-45% on Thursday increasing to 45-70% by Saturday.

FGZ WATCHES/WARNINGS/ADVISORIES

None.