An abnormally strong and cold weather system impacted the Desert Southwest during late January. The storm produced significant snowfall for elevations above 3,500-4,000 feet over the course of the two days, mainly north and east of the Phoenix area. This led to the closures of US-60 between Globe and Show Low and SR-87 between Bush Highway and Payson. Following the passage of a cold front and squall line through south-central AZ, midday on the 25th, snow levels briefly crashed to as low as 1500-2000 feet. This resulted in light snow/graupel accumulations at these lower elevations which included the Wickenburg area and foothill regions just north and east of the Phoenix metro area. Mixed precipitation (rain, some snowflakes, graupel, and small hail) was also reported across the Phoenix metro, with some accumulating small hail or graupel. This created a large media interest across the Phoenix area.

Heavy Snow in MAZATZAL MOUNTAINS, ARIZONA
From 25-JAN-21 16:00:00 to 26-JAN-21 20:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

A cold weather system moved through the region and produced multiple rounds of snowfall along the Mazatzal mountains and portions of SR-87, mostly from midday of the 25th through the morning of the 26th. A Winter Storm Warning was in effect during this time for elevations above 4,000 feet. The heaviest snow likely fell in the afternoon of the 25th when a squall line/cold front moved west to east through the area, producing greater precipitation rates and lowering snow levels briefly as low as 1,500-2,000 feet. No official snowfall measurements were reported, but the Arizona Department of Transportation (ADOT) shared multiple images from SR-87 near Mt. Ord in the afternoon of the 26th showing several inches of snow had accumulated. ADOT had closed SR-87 between Bush Highway and Payson beginning at around 1600 MST on the 25th and eventually reopened the highway around 1900 MST on the 26th.

Heavy Snow in PINAL/SUPERSTITION MOUNTAINS, ARIZONA
From 25-JAN-21 14:00:00 to 26-JAN-21 21:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A cold weather system moved through the region and produced significant snowfall in the Top-Of-The-World area along US-60 near the county border between Maricopa and Gila counties. Several inches of snow fell from the afternoon of the 25th through the morning of the 26th. A Winter Storm Warning was in effect at the time for this area for elevations above 4,000 feet. Per a public report at 1330 MST on the 26th, at roughly 4,700 feet just north of US-60, a storm total snowfall accumulation was measured around 8-10 inches. Additionally, a trained spotter reported a storm total of 5-7 inches fell in the area of milepost 161 along SR-77, south of Globe, at an elevation around 4,800 feet.

Heavy Snow in GLOBE/MIAMI, ARIZONA
From 25-JAN-21 22:30:00 to 26-JAN-21 20:30:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A cold weather system moved through the area and produced a period of snowfall in the Globe area, mostly from the afternoon of the 25th through the morning of the 26th. A Winter Storm Warning was in effect during this time for elevations above 3,500 feet. A trained spotter in Miami, at roughly 3,500 feet, initially reported snow was falling with less than a quarter mile visibility at 1600 MST on the 25th, but that snow had not begun to accumulate yet. An Arizona Department of Transportation (ADOT) webcam on US-60 heading northeast out of Globe showed 1-2 inches of snow had accumulated on the sides of the highway with a dusting on the road at 0300 MST on the 26th. ADOT had previously closed US-60 between Globe and Show Low, Arizona beginning around 1800 MST on the 25th and did not reopen the highway until around 1700 MST on the 26th. A COOP observer in Globe, at 3,600 feet elevation, measured 4.5 inches storm total snow by early afternoon on the 26th, meeting local warning criteria for snowfall within 24 hours.

Winter Weather in AGUILA VALLEY, ARIZONA
From 25-JAN-21 19:30:00 to 25-JAN-21 21:30:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A squall line/cold front associated with a cold weather system moved through south-central AZ in the early afternoon of the 25th. Immediately following the front, snow levels crashed rapidly down to as low as 1,500-2,000 feet. This led to a short period of light snow or graupel with light accumulations. A trained spotter in Wickenburg reported light snow accumulations at around 2,100 feet elevation. This event generated large public and media interest.

Winter Weather in CAVE CREEK/NEW RIVER, ARIZONA
From 25-JAN-21 21:00:00 to 25-JAN-21 23:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A squall line/cold front associated with a cold weather system moved through south-central AZ in the early afternoon of the 25th. Immediately along and following the squall line, snow levels crashed rapidly down to as low as 1,500-2,000 feet. Numerous weather stations measured surface temperatures falling from around 50 degrees to the mid-30s in a matter of 10-20 minutes. This led to a short period of light snow or graupel with accumulations of a dusting and up to an inch in foothill communities like North Scottsdale up to the Cave Creek/Carefree area. Accumulated snow was also observed on the surrounding mountains like the McDowell mountains, visible to a large population of the Phoenix metro area. Snowflakes mixed in with rain and small hail was even observed at lower elevations, below 1,500 feet, within the Phoenix metro area. This event generated large public and media interest.