Southwest Idaho is in for another stretch of hot weather before temperatures cool and storm chances increase heading into the weekend.
A Heat Advisory is in effect Thursday afternoon through Friday for the Treasure Valley, western Magic Valley and Upper Weiser River Valley. Highs across the lower elevations will generally reach the upper 90s to low 100s, with much of the Treasure Valley expected to climb between 100 and 103 degrees. Increasing clouds could knock a couple of degrees off Friday's temperatures, but it will still be very hot.
Changes begin Friday as more moisture moves into the region. Afternoon showers and thunderstorms will first develop over the higher terrain near the Idaho-Nevada border before spreading farther north through the evening. A few storms could continue into Friday night. Gusty outflow winds will be the main concern with any storms that develop.
By Saturday, a weather system moving through the Pacific Northwest will help bring temperatures down about 5 to 10 degrees compared to Friday. Shower and thunderstorm chances will also become more widespread. With additional moisture in place, some storms could produce heavy rainfall and gusty winds, especially across southwest Idaho. Southeast Oregon could also see wind gusts between 25 and 35 mph Saturday afternoon.
A cold front will move through Saturday night, bringing another noticeable cooldown for Sunday. Highs across the lower elevations will fall to around 90 degrees, which is closer to normal for this time of year. Most areas will dry out, although a few thunderstorms will remain possible near the Idaho-Nevada border and eastern Boise Mountains.
Temperatures will begin climbing again next week as warmer-than-normal weather returns. Some afternoon thunderstorms will remain possible over the mountains of southwest Idaho early in the week before drier conditions take over for most areas by Wednesday.
