Warm Friday, then a windy and rainy weekend

Tucson residents should prepare for a sharp change in conditions between Friday’s summerlike warmth and a much more unsettled weekend. High temperatures are expected to reach the mid to upper 90s Friday, while showers and thunderstorms could develop across southern Arizona. The weekend brings additional rain chances, potentially heavy storms, gusty winds and a noticeable drop in temperatures. A Wind Advisory is scheduled for central and western Pima County and southwestern Pinal County from 2 a.m. through 11 p.m. Sunday.

Friday will begin warm and mostly sunny, with Tucson’s high near 97 degrees and a 20 percent chance of showers and thunderstorms after 11 a.m. Winds are expected to come from the southeast at 5 to 14 mph before shifting southwest during the afternoon. A few showers or storms may form in the higher terrain and move onto the desert floor, although most locations are expected to receive little rainfall.

Storms that do develop Friday could still produce brief downpours and wind gusts between 35 and 40 mph. The greatest chance for activity extends from southern Pinal County south to the international border. Friday night should be partly cloudy, with only a 10 percent chance of showers or thunderstorms before 8 p.m. and a low near 74 degrees. For people commuting, working outdoors or making evening plans, the main concern will be quickly changing conditions rather than widespread rain.

Saturday is expected to bring more clouds, scattered showers and thunderstorms. The chance of precipitation rises to 60 percent, with showers possible late in the morning and more likely after 2 p.m. Tucson’s high should reach about 92 degrees, with breezy conditions as winds shift from the southeast to the west southwest. Saturday night could be stormier, with showers and possibly a thunderstorm likely before 11 p.m., followed by additional chances for showers and thunderstorms overnight.

Forecasters warn that some Saturday storms may produce locally heavy rain, small hail and damaging wind gusts. Rainfall will not necessarily be uniform across the region, so one neighborhood may see a downpour while another receives little. The potential for sudden heavy rain could affect roads, washes and low lying areas, while hail and strong winds could create hazards for drivers and outdoor activities. Residents should be ready for conditions to change through the day and into Saturday night.

Sunday is expected to be the windiest day of the weekend. The advisory covers central and western Pima County, including the Tucson area, as well as southwestern Pinal County. South southwest winds are forecast to increase from about 13 to 18 mph to 19 to 24 mph during the afternoon, with gusts reaching 41 mph in the Tucson forecast. Another forecast describes possible gusts of 45 to 55 mph, with even stronger winds possible in thunderstorms.

Sunday also carries a 40 percent chance of showers and thunderstorms, along with the possibility of blowing dust after noon. The combination of strong winds, dust and rain may reduce visibility and make travel more difficult, especially for high profile vehicles. Sunday night brings a continued chance of showers, with temperatures falling to about 67 degrees. Anyone driving between Tucson and communities in Pinal County should monitor conditions before leaving and be prepared for sudden wind or rain.

The unsettled pattern will continue into early next week, even as temperatures fall. Monday’s high is expected to be near 80, with a 30 percent chance of morning showers and a 20 percent chance of showers or thunderstorms Monday night. Tuesday should reach only about 77 degrees, with a 30 percent chance of showers or thunderstorms, mainly before 11 a.m. Overnight lows are expected to drop into the upper 50s by Tuesday night and remain near 56 degrees Wednesday night.

The broader weather pattern is part of a series of storm systems moving across Arizona. A separate report described rain, snow and strong winds affecting northern and eastern parts of the state, including more than four inches of snow near Flagstaff and wind gusts as high as 74 mph in Springerville. A winter storm watch was issued for parts of northern Arizona, where several inches of additional snow and winds up to 50 mph were possible. While those high country impacts are not expected in Tucson, they underscore the strength of the weather pattern moving through the state. Conditions should begin clearing by midweek, with highs gradually returning to the 80s by the end of the week.