A Red Flag Warning is in effect for parts of south-central Idaho Wednesday afternoon as hot, dry, and windy conditions create elevated fire weather, while isolated thunderstorms will bring gusty outflow winds and lightning to parts of the region.
Warm and dry conditions will continue today with generally light winds across the forecast area. A weak shortwave trough will move through the region Wednesday evening, bringing a slight chance of showers and thunderstorms primarily north of a Mountain Home to Burns, Oregon line. The main hazards with these storms will be gusty outflow winds up to 35 mph and lightning. Rainfall amounts will be low, generally less than a quarter inch under the heaviest showers and thunderstorms.
Gusty wind and dry conditions raise the fire danger in Scott Dorval's video forecast
The more significant concern Wednesday will be the fire weather conditions. A cold frontal passage will bring wind gusts up to 40 mph and single-digit relative humidity values in the Lower Snake River Valley during the late afternoon and evening. These hot, dry, and windy conditions have prompted the issuance of Red Flag Warnings for fire zones in south-central Idaho. Temperatures will moderate briefly on Thursday with breezy northwest winds keeping temperatures about 10 degrees cooler than Wednesday.
An intense upper-level low-pressure system will move into the Pacific Northwest on Friday, spreading southwesterly flow over the region and providing a warming and drying trend. Temperatures will hover around 10 degrees above normal on Friday, with highs reaching 90 degrees. As this strong low moves east through the weekend, a cold front will sweep through the area. The primary threat with this system will be widespread wind gusts of 20 to 35 mph, with higher terrain and southeast Oregon seeing gusts of 30 to 40 mph. Gusts of 30 to 45 mph are possible through the Snake River Plain late Saturday afternoon into evening.
High temperatures behind the cold front Saturday and Sunday will drop 10 to 15 degrees from Friday, dipping to slightly below normal by Sunday. The trough is expected to weaken as it moves inland, keeping the area mostly dry with only a 10 to 15 percent chance of showers and thunderstorms over the west-central Idaho mountains. Temperatures will warm back to 5 to 10 degrees above normal by Monday.
Tonight
Mostly clear, with a low around 55. Light wind.
Wednesday
Increasing clouds with an isolated shower possible in the early evening and a high near 89. Light morning wind becoming breezy late in the day with gusty evening wind.
Wednesday Night
A 20 percent chance of showers and thunderstorms before midnight. Mostly cloudy, then gradually becoming clear, with a low around 53. Gusty wind diminishing.
Thursday
Sunny & pleasant, with a high near 80. WNW wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday Night
Clear, with a low around 52.Diminishing wind after sunset.
Friday
Sunny and hot, with a high near 90.
Friday Night
Clear, with a low around 55.
Saturday
Sunny & becoming very breezy, with a high near 81.
Saturday Night
Mostly clear, with a low around 48.
Sunday
Sunny & breezy, with a high near 77.
Sunday Night
Mostly clear, with a low around 49.
Monday
Mostly sunny, with a high near 88.
Monday Night
Partly cloudy, with a low around 56.
Tuesday
Mostly sunny and hot, with a high near 90.
