Lingering moisture and isolated thunderstorms will continue through Tuesday before a warming and drying trend delivers near-normal temperatures and dry conditions for the Fourth of July holiday weekend.
Temps heating up into the long holiday weekend in Scott Dorval's video forecast
Light showers will continue through this evening under lingering moisture and weak dynamics on the back side of the departing low-pressure system. As the upper-level support departs, skies are expected to clear overnight, allowing temperatures to reach about 5 degrees below normal.
A shortwave passage is on track for Tuesday afternoon and will combine with residual low-level moisture and weak instability to support isolated thunderstorm development. A few storms will initially develop across Malheur and Baker County Tuesday afternoon before tracking eastward into southwest Idaho during the late afternoon and early evening hours. The main threats with these storms will be gusty outflow winds and lightning.
By Wednesday, the shortwave exits to the east, bringing mostly clear skies back to the region. Temperatures will gradually warm through the period, reaching the low 80s in the Western Snake River Basin by Wednesday. Isolated thunderstorms remain possible (20 percent chance) along the Idaho-Nevada border and across the central Idaho mountains where moisture and instability remain sufficient.
Continued troughing will remain over the region Thursday and Friday, with the last of the embedded shortwaves bringing isolated showers and thunderstorms across the higher terrain of southwest Idaho and cooler than normal conditions through the end of the week.
Fourth of July Outlook
The timing of the warming trend could not be better for the holiday weekend. The Four Corners ridge will intensify over the weekend, bringing higher atmospheric heights and rising temperatures back to near normal. The combination of warm but not excessively hot temperatures and dry conditions should make for a very pleasant Fourth of July. There is an outside chance of 10 to 20 percent probability of temperatures exceeding 95 degrees on July 4th through the lower Snake River Plain.
Mountain Recreation Outlook for the Holiday Weekend
For those heading into the mountains of Idaho for the holiday weekend, conditions will be generally favorable. The warming trend will bring comfortable temperatures to mountain valleys and higher terrain. While isolated thunderstorms are possible Thursday and Friday over higher terrain, the weekend itself looks dry and pleasant. Hikers, campers, and outdoor enthusiasts should be aware of the lingering thunderstorm potential Thursday and Friday before conditions improve for the holiday.
Tonight
Partly cloudy, with a low around 52. NW wind 5 to 8 mph becoming calm in the evening.
Tuesday
Mostly sunny, with a high near 80. Light NW breeze.
Tuesday Night
A 20 percent chance of showers and thunderstorms before 9pm. Mostly clear, with a low around 54. Light wind.
Wednesday
Sunny, with a high near 82. Light NW wind
Wednesday Night
Mostly clear, with a low around 53. Light wind.
Thursday
Mostly sunny & warmer, with a high near 85.
Thursday Night
Partly cloudy, with a low around 56.
Friday
Sunny & warm, with a high near 86.
Friday Night
Clear, with a low around 55.
Independence Day
Sunny and hotter, with a high near 90.
Saturday Night
Clear, with a low around 58.
Sunday
Sunny and hot, with a high near 95.
Sunday Night
Partly cloudy, with a low around 62.
Monday
Sunny and hot, with a high near 96.
