textproduct: NWS Flagstaff

SYNOPSIS

Winter weather expected to return for many locations in northern Arizona Wednesday and Thursday. Cold daytime highs and snow accumulation down to ~6000' feet expected. Cold temperatures look to stick around through the weekend, but gradually seeing improvement each day.

DISCUSSION

If you've been waiting for more snow across the High Country, then looks like you're in luck! There are two low pressure systems forecast to impact the Southwest Wednesday and Thursday, but each one will be bringing their own components to this upcoming winter weather event. The first system is already centered off the southern California Coast and will continue to dive towards southern Arizona between now and early Thursday morning. The trajectory of this disturbance will allow for the main push of moisture to move into the state. This first system will also be warmer, so rain and high elevation snow will kick off the precipitation, as snow levels will initially be around 7000-7500' on Wednesday. Snow levels will continue to fall heading into Thursday due to the second disturbance pushing down from the Great Basin Region. This next low will be the main provider of cooler temperatures, which will allow snow accumulation to reach down to 5500-6000'. This second system will also have additional moisture associated with it, so continuous rain and snow showers will persist through Thursday.

So now that we've discussed the mechanics of these storm systems, let's talk about the good stuff...snow amounts/timing. As previously stated, the start of the precipitation will vastly be rainfall, minus locations generally above 7500'. A wintery mix is certainly possible down to 7000', but we aren't anticipating accumulation down to more populated areas (Flagstaff, Williams, Kachina Village) until late Wednesday/early Thursday. Overall snow totals above 6500' between Wednesday afternoon and Friday morning look to be 2-6 inches. A few locations across the Mogollon Rim could see 5-10" due to more enhanced upsloping, and then areas above 8000' could be seeing a foot or more of new snow. Although this isn't the storm of the century or anything, it will be enough to impact travel throughout Thursday. If you have a morning and/or afternoon commute, I would plan on giving yourself extra time! Roads will become snow covered between Williams and Winona along I-40 and similarly along I-17 between Flagstaff and Munds Park throughout Thursday. It's always encouraged for people to check AZ511.com for updated road conditions, and be sure to have a winter-weather emergency kit in your vehicle.

Once the precipitation moves eastward, we'll be left with bitterly cold temperatures on Friday. Many locations above 6500' probably won't break 32 degrees...so be sure to bundle up! Overnight lows will also be rather frigid, with many areas along the north of the Mogollon Rim reaching single digits. Although we'll see slight improvement of daytime highs each day, overnight lows may take a few days to truly recover due to the northeasterly flow that sticks around behind the parting storm systems.

AVIATION...Wednesday 07/06Z through Thursday 08/06Z

Look for VFR conditions under scattered/broken upper-level clouds through 18Z. After 18Z, -SHRA/SHSN developing with MVFR conditions over the mountain areas along and south of a KSOW-KFLG-KGCN line Wednesday afternoon. Wednesday evening, deteriorating conditions with widespread SHRA/SHSN along with MVFR/IFR conditions. Light and variable winds tonight will be followed by southwest winds at 10-20 kts on Wednesday.

OUTLOOK...Thursday 08/06Z through Saturday 10/06Z...Widespread SHRA/SHSN, heaviest 12Z Thursday-06Z Friday. Snow level near 7000 feet early Wednesday evening lowering to near 4000 feet by Thursday evening. Widespread MVFR with areas of IFR/LIFR (especially the mountains) conditions forecast. Improving conditions by 12Z Friday. Gusty west-southwest winds at 15-30 kts are expected on Thursday, transitioning to north-northwest by Thursday evening. Winds remain elevated on Friday but from the north-northeast due to cold front passage.

FIRE WEATHER...Wednesday and Thursday

Active winter weather will take place Wednesday and Thursday resulting in blustery winds, decreasing temperatures, and chances for rain and accumulating snow. Temperatures remain near average on Wednesday with breezy southwest winds, 10 to 25 mph. Precipitation begins later Wednesday afternoon with snow above 7000 feet and rain elsewhere. Temperatures plunge Wednesday night and into Thursday with snow down to 5000 feet. Plan on daytime highs 10 to 15 degrees below average on Thursday with west to northwest winds, 20 to 35 mph.

Friday through Sunday...Cold temperatures are anticipated on Friday with highs 15 to 20 degrees below average. Winds will shift to the north-northeast, 15 to 25 mph, throughout the day with mainly dry conditions. Temperatures begin to warm-up gradually for the weekend as northeast winds prevail, 10 to 25 mph, each day and night. Conditions remain dry into next week.

FGZ WATCHES/WARNINGS/ADVISORIES

None.