Outdoor plans for the long weekend? You might need your slicker. Here’s the forecast
If you were looking to get outside or go adventuring over the three-day weekend, you could be out of luck — unless you enjoy the rain.
Forecasters said periods of showers were likely to sweep over the Treasure Valley starting Friday night, likely providing a gloomy and wet Martin Luther King Jr. Day weekend.
The total rainfall won’t amount to much — only about a tenth of an inch is expected in Boise, National Weather Service meteorologist Stefanie Henry told the Idaho Statesman on Thursday — but storms will provide a steady drizzle throughout the weekend.
There is a slight chance of snowflakes mixing in with the rain Sunday night into Monday morning, according to the National Weather Service, but warm temperatures will prevent any accumulation.
“It’s going to be warm enough for rain beginning Saturday morning, and then another wave will come in on Saturday night,” Henry said. “So there might be some breaks in between, but we’re fairly active through the weekend, and then on Sunday, we have another wave of moisture that comes in.”
Boise’s high temperatures were forecast to drop slowly throughout the weekend as a cold front arrived, starting with a high of 53 degrees on Friday and falling to a high of 44 on Monday. The low temperature was forecast to bottom out at 31 degrees on Monday night.
What’s with the active weather pattern?
As of Thursday, Boise had received measurable rainfall four times in January, and trace rainfall on another two occasions. With precipitation expected every day this weekend, the City of Trees will have received at least a trace amount of rain on 10 of January’s 16 days through Monday.
The increased precipitation and warmer temperatures result from an active Pacific jet stream drawing subtropical moisture from points to the south. Subtropical moisture is typically warmer, more humid and carries more water.
“We’ve gotten a lot of southerly-southwest flow,” Henry said. “And yeah, it’s just been kind of the storm door has just stayed open this whole time.”
Henry said Idaho received colder weather and more snowstorms in November and December because much of the region’s moisture was coming from Canada.
She expects that trend to return in a couple of weeks, but until then, the state will enjoy above-average temperatures. The normal high temperature for Boise in mid-January is 38 to 39 degrees.
“Sometime late next week or next weekend, we might start to see a little bit colder weather coming in from Canada,” Henry said. “There’s actually some colder weather that might come in as early as Monday; our temperatures are going to start trending down starting Sunday.”
This story was originally published January 13, 2023 at 4:00 AM.
