Brrrr: Freeze warning for Tucson, Southern Az on Monday night
Operation Deep Freeze activated for homeless shelter
Temperatures could fall below freezing in parts of Southern Arizona overnight Monday, with a freeze watch in effect for the Tucson area, Green Valley, the Tohono O'odham Nation and the desert northwest of the metro area.
Thermometers could read as low as 30-32 degrees in the Tucson metro area, with some washes and drainage areas dropping into the 20s NWS officials said. The warning will be in effect from 1 a.m. to 9 a.m. Tuesday, with a cold and dry mass of air causing temperatures to drop. A warmer easterly wind may mix with the cold front, causing temperatures to stall just above freezing, NWS officials said, with gusty winds persisting through Wednesday afternoon.
Besides Tucson, the watch will cover 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.
An updated forecast Monday morning upgraded the NWS advisory from a watch to a warning, and temperatures are expected to be several degrees colder than indicated in the forecast notice released Sunday.
With very dry and clear conditions and light winds, temperatures are expected to fall rapidly Monday evening, officials said.
Due to the cold forecast, Tucson's "Operation Deep Freeze" has been activated. The emergency shelter for homeless people will be open at the Salvation Army Hospitality House, 1002 N. Main Ave., from 2-5 for intake. A dinner will be served 5-6 p.m. Monday.
Tucson's winter severe-weather emergency shelter for homeless people goes into effect when weather predictions are for overnight temperatures of 40 degrees or lower with rain, 35 or lower without rain, or when wind chill factors indicate a health hazard from exposure.
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.