Good Morning Idaho! ☀️🌫️
Yesterday was mostly cloudy, and while some fog slowly lifted, areas stuck under it struggled to warm up at all. Boise only topped out at 32°!
Today starts off with dense fog again for the morning commute, but there’s a bit of a change in the setup. With the ridge axis now offshore, northerly flow is pulling in another push of cold air, and a surface high will increase easterly winds across the region today. That breeze will be most noticeable along the Snake Plain, and it could help break up some of the fog and low clouds this afternoon. Either way, the Dense Fog advisory is now in effect through 1 pm this afternoon.
That said, the big question mark is along the Snake River corridor from Bruneau to Ontario, where fog may hang on longer. If the fog sticks around, temperatures will struggle to climb above freezing again. Highs today will generally land in the mid-30s to upper-30s, with colder readings where fog lingers.
Outside of the fog and stratus, skies will look mostly clear, and mountain temperatures cool back closer to seasonal levels today, then warm a bit this weekend as the ridge builds back overhead.
As we head into the weekend, that easterly wind push is brief — so fog is expected to redevelop overnight and remain a morning issue again Saturday and Sunday. The best clearing window this weekend looks to be Saturday afternoon into Sunday, especially for areas that can break into sunshine. There are also signs fog coverage could expand into Malheur and Baker counties.
Next week: the quiet, dry stretch keeps going. The ridge begins to flatten a bit as the Polar Vortex expands westward, but it still looks strong enough to keep the coldest air east of us. Dry and stable conditions continue through at least Wednesday, and while there’s a 20–30% chance of mountain showers Thursday into Friday, most of the deeper moisture still tracks around us.
One thing to watch late next week: if the inversion finally breaks, temperatures may flip — warming up in the valleys while cooling down in the mountains.
