A building ridge of high pressure will drive a steady warming trend through the work week, pushing Treasure Valley temperatures to near or slightly above 100 degrees Thursday and Friday before a pattern change brings cooler temperatures and increasing storm chances for the weekend especially in the mountains.
Sizzling heat is on the way again in Scott Dorval's video forecast
Heat Builds to 100 Degrees Thursday and Friday
Temperatures will climb steadily through the week, reaching 96 degrees Wednesday before the heat intensifies to near 100 degrees Thursday and Friday. Temperatures will run 8 to 12 degrees above normal during this stretch, making for sizzling heat conditions. Residents should take precautions to stay cool and hydrated, limit strenuous outdoor activities during the hottest parts of the afternoon, and check on vulnerable neighbors and family members.
A push of monsoon moisture will primarily stay to the south Thursday afternoon, though there is a low 10 to 20 percent chance of showers and thunderstorms over the Magic Valley late Thursday. Rainfall accumulations will be minimal with any storms that form, so gusty outflow winds and lightning will be the primary concerns.
Pattern Change Brings Relief Saturday and Sunday
The upper-level trough will move inland late Friday into Saturday, bringing a welcome cooldown to the region. Temperatures will drop to near normal Saturday and Sunday, with highs falling to 94 degrees Saturday and 90 degrees Sunday. Increased moisture and cooling aloft will support a 20 to 30 percent chance of showers and thunderstorms across higher terrain of southwest Idaho Friday through Sunday, shifting to mostly southwest Idaho for Saturday and Sunday.
Central Idaho Mountains
The central Idaho mountains will see the best chances for showers and thunderstorms this weekend as the upper-level trough moves through. The 20 to 30 percent chance of storms Friday through Sunday will bring gusty outflow winds and lightning as the primary hazards, with some localized heavy rain possible. Anyone planning to be in the mountains this weekend should monitor conditions closely.
Looking Ahead to Next Week
Long-range models hint at the Four Corners ridge rebuilding over the area early next week, with temperatures warming again to the low to mid-90s. Moisture early next week remains uncertain, with some models showing a strong surge with higher precipitation chances while others show a more limited scenario. The current forecast shows a 10 to 30 percent chance of showers and thunderstorms over southwest Idaho early next week.
Tonight
Mostly clear, with a low around 62. Northwest wind 5 to 8 mph becoming calm in the evening.
Wednesday
Sunny and hot, with a high near 96. Calm wind becoming northwest around 5 mph in the afternoon.
Wednesday Night
Mostly clear, with a low around 65. North northwest wind around 5 mph becoming calm in the evening.
Thursday
Sunny and hot, with a high near 100. Calm wind becoming west around 5 mph in the afternoon.
Thursday Night
Partly cloudy, with a low around 68. Northwest wind 5 to 7 mph becoming calm after midnight.
Friday
Mostly sunny and hot, with a high near 100.
Friday Night
Mostly cloudy, with a low around 68.
Saturday
Partly sunny and hot, with a high near 94.
Saturday Night
Mostly clear, with a low around 62.
Sunday
Sunny and hot, with a high near 90.
Sunday Night
Mostly clear, with a low around 62.
Monday
Mostly sunny and hot, with a high near 94.
Monday Night
Partly cloudy, with a low around 64.
Tuesday
Mostly sunny and hot, with a high near 93.
