Frosty: Hard freeze warning for Tucson through 9 am Sunday
Temperatures could fall below freezing in Southern Arizona overnight Saturday, with a hard freeze warning in effect for the Tucson metro area, Green Valley, Marana and Oro Valley and the Tohono O'odham Nation through Sunday morning.
A winter weather advisory is in effect for the rest of Southeastern Arizona, including Sierra Vista, Bisbee and Douglas, and a freeze warning covers the western desert areas around Ajo and north to the Phoenix metro area.
Thermometers could read as low as 28 degrees in the Tucson area, with some washes and drainage areas dropping into the middle 20s, National Weather Service officials said. The warning will be in effect from midnight Saturday to 9 a.m. Sunday, with "widespread freezing low temperatures likely Sunday and Monday morning."
Another winter weather system is forecast for around New Year's Day, officials said.
Besides Tucson, the hard freeze warning covers Green Valley, much of Oro Valley and Marana, Catalina, Picacho Peak and Eloy, and large stretches of the Tohono O'odham Nation west of Tucson.
Highs Saturday are running "quite chilly," NWS said: about 15 degrees below normal. A cold, dry mass of air is moving in behind the passing winter storm system Saturday.
With clearing skies, temperatures are expected to fall rapidly Saturday evening, officials said.
New Year's Eve could see mountain snow and valley rains around Tucson and to the south, forecasters said.
Wrap your pipes, cover your plants, bring your pets inside and be kind to people who are outdoors at night. NWS is forecasting temperatures may drop as low as the upper 20s in some parts of Southern Arizona. The coldest temperatures are expected around daybreak on Tuesday.
"Thanks to the wind, any one place in Tucson should only freeze for a couple hours" overnight, officials said.
Lows Tuesday morning are forecast to be 33 degrees in Tucson (hovering just above freezing). South and east of the metro area, cold temperatures are already the nightly norm, with the Weather Service not issuing a caution for temperatures that will drop to 26-28 degrees in Nogales and Sierra Vista, 20 degrees in Douglas and a chilly 19 in Willcox.
Frost and freezing conditions can kill crops, damage other sensitive plants and potentially damage outdoor plumbing that isn't protected.
Slightly warmer temperatures will return Wednesday, with a warming trend continuing into the weekend, officials said.