Calm, warm weather gives way to weekend rain, mountain snow

IDAHO FALLS, Idaho (KIFI)- Calm weather will linger across Idaho through Thursday night before gusty winds arrive on Friday ahead of a major weekend weather shift.

Thursday night will bring mostly clear skies with a low temperature around 44 degrees and light south-southwest winds between three and six mph. Friday will be sunny with a high near 81 degrees, but winds will shift to the southwest and pick up in the afternoon, reaching 12 to 17 mph with gusts up to 30 mph.

Friday marks the final day of dry, warm weather before a low-pressure system moves into the region over the weekend. Winds across central and eastern Idaho are expected to reach 25 to 35 mph on Friday, with gusts in the central mountains reaching up to 40 mph. Weather forecasters noted that these strong winds combined with dry conditions could lead to critical or near-critical fire weather conditions in some areas. Friday night will turn partly cloudy with a low around 53 degrees and south winds gusting up to 25 mph.

The weather changes are linked to a low-pressure system moving across the West through early next week. Remnants of tropical moisture from Rachel are expected to pull north into portions of central and eastern Idaho, bringing rain and mountain snow.

Precipitation totals across the region will vary. The South Hills and Albion Mountains are expected to receive between one and two inches of precipitation. Higher ridgelines east of I-15 are forecast to see 2.25 to 2.5 inches, while the Snake Plain from Pocatello up through Rexburg is forecast to receive 1.0 to 1.Five inches. Drier valley areas in the central mountains are expected to see between 0.10 and 0.30 inches of precipitation.

Cold air moving in with the system will lower snow levels. Accumulating snow is expected above 7,000 feet in the central mountains and near Island Park, where higher peaks could see several inches. Snowflakes could fall at lower elevations on Sunday and Monday as temperatures drop, though whether snow will stick at lower levels remains uncertain.

Another low-pressure system is expected to drop into the western states by the middle of next week, which will keep cooler air and precipitation chances in the forecast.