Red flag warning issued for gusty winds and low humidity through Sunday

IDAHO FALLS, Idaho (KIFI)- A Heat Advisory remains in effect until midnight tonight as temperatures across much of Idaho reach up to 103 degrees. Near-record heat is expected to persist through the evening before a cooling trend arrives early next week.

The National Weather Service also issued a Red Flag Warning for gusty winds and low humidity until 9 p.m. Sunday. Forecasters warned that the combination of high winds and very low humidity will create dangerous fire weather conditions across several Idaho fire weather zones.

High temperatures in lower elevations will reach approximately 100 degrees today. The National Weather Service has issued the Heat Advisory for the Lower and Upper Snake River Plains, Magic Valley, Teton Valley and the Shoshone and Lava Beds regions. Other affected areas include the Challis, Pahsimeroi and Lost River valleys, as well as the Southern Hills and Albion Mountains.

The Red Flag Warning for fire conditions covers the Upper Snake River Valley, the Sawtooth Range, the Middle Snake River Valley and the Salmon River Mountains. Winds in these zones are expected to blow from the west at 15 to 25 mph, with gusts reaching up to 40 mph. These winds will be paired with relative humidity levels dropping to 8%.

Conditions on Sunday will include patchy smoke between 10 a.m. and 4 p.m. The high temperature is expected to be near 90 degrees. Southwest winds are forecast to increase in the afternoon to speeds between 18 and 23 mph, with gusts as high as 37 mph.

A dry upper-level trough moving through Idaho will shift the airflow to the northwest, allowing cooler Canadian air to enter the region. Temperatures on Monday are forecast to drop into the 80s in lower elevations and the 70s in the mountains. This cooling trend is expected to remain below normal levels through Wednesday. Forecasters expect the cooldown to be short lived as an upper ridge begins to rebuild on Wednesday.

High temperatures in lower elevations are projected to return to the mid-90s by Thursday. Current forecast models indicate a dry eight-day period across the region.

No precipitation is expected in the forecast through next Saturday. The upper ridge is scheduled to continue rebuilding through next weekend.