A line of rain and thunder is headed for Cortez Monday night, likely bringing 0.15 inches of rain to low elevations and 4-8 inches of snow to the San Juan Mountains through Tuesday night.

Tom Renwick, forecaster for the National Weather Service in Grand Junction, said lighting struck 150 miles west of Cortez early Monday as a low-pressure system over southwest Utah brings moisture and warmer temperatures to the Four Corners.

“There’s some (lightning) out there already and it’s only 10 o’clock in the morning in the middle of October, end of October, so it’s kind of cool,” Renwick said on Monday.

In Cortez, he said the southwest sky should be getting dark by 6 p.m., there should be some precipitation by 8 p.m., and by midnight, it will shift to the northeast. The models predict approximately 0.15 inches of rain in the city, which he said is a “really small amount.”

“However, if you get a storm and thunderstorm, it could get quite a bit more than that,” Renwick said. “But for that to go right over Cortez is kind of like a needle in a haystack kind of thing.”

The forecast shows a 50 percent chance of precipitation on Monday afternoon, a 70 percent chance on Monday night and a 60 percent chance on Tuesday. A few of the thunderstorms may produce hail, heavy rain and gusty outflows, according to the National Weather Service.

The system should clear up by Wednesday, at which point Renwick said the Four Corners will revert to a high-pressure system for about a week. He said that means warmer temperatures. Thermostats could reach 61 degrees in Cortez on Wednesday and 64 on Friday.

sdolan@the-journal.com