It was a cold start to 2019 across the state, with temps dropping to the upper 30s and low 40s in the Phoenix area.
Arizona also welcomed the new year with rain and snow throughout the day Monday.
By noon, areas in northern Arizona had already seen upwards of 8 inches of snow. Weather conditions slowed traffic and caused several crashes or slide-offs.
Snow showers continued overnight for eastern Arizona while rain showers continued overnight south and east of Phoenix, NWS said.
PHOTOS: Snow falls in Arizona on New Year's Eve
9:54 p.m.
NWS in Flagstaff says snow will slowly decrease from west to east overnight, persisting across far eastern Arizona through New Year's Day before ending. For the remainder of the night, the heaviest snow will be from Heber to the Four Corners area, according to NWS.
8:46 p.m.
SR 87 reopened south of Payson, but weather continues to slow traffic in the area. ADOT is urging drivers to delay travel until the weather improves.
7:57 p.m.
A crash closed southbound SR 87 south of Payson after an earlier crash had already caused delays, according to ADOT. There is no estimated time to reopen the highway.
5:26 p.m.
Flagstaff has received up to 4.5 inches of snow, NWS says. The Pine-Strawberry area racked up 7 inches of snow, Winslow received 4 inches of snow and Prescott up to 7 inches.
4:54 p.m.
In the Valley, spotty, light to moderate showers will continue through this evening with temperatures falling through the 40s.
Team 12's Lindsay Riley says there will be a chance for an isolated shower even at midnight as we ring in 2019. The temperature is still looking to be in the low 40s as the ball drops.
4:46 p.m.
Snow is dwindling down in the Flagstaff area, meteorologist Lindsay Riley says. Only 1 to 2 more inches of snow is expected through the rest of the night but it's a different story for the Rim and the White Mountains.
The rim is looking at an additional 6 to 12 inches of snow and winter storm warnings will continue through Tuesday afternoon.
4:04 p.m.
Down south, NWS Tucson says snow has reached Mt. Lemmon and more than 1 foot of snow is expected to fall.
3:42 p.m.
ADOT says these closures are currently in effect due to weather and crashes”
SR 260 has closed in Star Valley.
SR 87 southbound is closed at milepost 251, south of Payson.
SR 87 Northbound is closed at milepost 254, north of Payson.
State Route 89A has been closed in both directions north of Jerome from mileposts 343-347.
State Route 89 northbound is closed at milepost 297 due to a crash.
3:18 p.m.
The focus of the heaviest snowfall is currently shifting toward the Eastern Mogollon Rim and northern Gila County.
2:51 p.m.
Snow in the Valley? Maybe! NWS says the potential for flurries or light snow will continue across northern parts of the Phoenix area this afternoon and evening.
2:32 p.m.
No snow in Phoenix but lots of rain! Be careful driving on slick roads.
1:36 p.m.
ADOT says SR 89A is "at a standstill" in Sedona, between mileposts 374 and 375, due to weather conditions
The department says both directions of I-17, between New River and Flagstaff, is "extremely slow" due to the weather.
12:45 p.m.
Arizona Snowbowl received 8 inches of snow by noon while Flagstaff and Prescott Valley both saw 2.5 inches and Cordes Junction received 1 inch.
ADOT is warning drivers to delay travel until winter storm passes.
"If you decide to travel during a snowstorm," ADOT tweeted, "be prepared for delays and the possibility that you will spend extended time in winter conditions due to slowing and closures caused by the weather."
11:49 a.m.
ADOT says there have been multiple crashes or slide-offs reported in the area of I-17, McGuireville and Cordes Junction.
11:35 a.m.
In the High Country, snow was already falling early Monday morning in places like Flagstaff, Cordes Lake and Prescott.
According to the National Weather Service in Flagstaff, as of 11 a.m. the heaviest snow showers were falling along I-17 near Camp Verde.
Snow was also falling in Wickenburg. And for those driving north on I-17,reports of snow started around Black Canyon City, according to NWS Phoenix.