Alaskan air will bring a ‘dramatic cool-down’ to Boise this weekend. How chilly will it get?
If you thought Boise’s temperatures were set for the summer, think again and start looking for those hoodies you stored at the back of your closet.
Two low-pressure systems from the Gulf of Alaska are primed to push through Idaho in the coming days, with high temperatures forecast to drop by nearly 30 degrees over the weekend. The second system, which arrives in Idaho on Monday, also brings a chance of rain for Boise.
Here’s what you need to know about this weekend’s weather and when it will warm back up.
Cold air from Alaska
The two low-pressure systems affecting Idaho this week are both coming from the Gulf of Alaska, bringing cold air with them.
The first will arrive Saturday, but the changes won’t be immediately apparent. The high temperature is expected to drop from 93 degrees on Thursday to 86 on Friday and then 74 on Saturday.
The main concern with the first pressure system is wind. The National Weather Service in Boise forecasts wind gusts up to 29 mph on Saturday, which is considered a strong breeze in which large tree branches will be in continuous motion.
“It’s nothing to be overly concerned about at this time,” Weather Service meteorologist Bill Wojcik told the Idaho Statesman on Thursday. “But it’s just one of those other things to be aware of, and it can get kind of windy as these systems come in.”
The dramatic drop in temperatures — and a chance for rain — will arrive with the second low-pressure system on Monday.
The second system will follow in the wake of the first but with a slightly more southerly track, bringing it closer to Boise. The high temperature on Monday is forecast at 67 degrees, while the nighttime temperature drops to a chilly 46.
From Thursday’s high temperature of 93 to Monday’s low of 46, Boise will experience a 47-degree drop.
“It’s a really dramatic cool-down because of those two systems coming in from the northwest,” Wojcik said.
Potential for rain in Idaho
The Weather Service forecasts a 20% chance of rain on Monday and Tuesday for Boise, but Wojcik said that percentage will likely shift as we get closer.
Forecasts as of Thursday morning showed the system tracking north of Boise and bringing heavier rain around the McCall area. Light snow is also possible at elevations above 7,000 feet, Weather Service meteorologist Josh Smith told the Statesman.
“If it comes farther south over Boise, those probability of precipitation where we have 20%, those numbers would go up,” Wojcik said. “So as we get closer to that event, early next week, we could see the probabilities increasing depending on the storm track.”
The system will bring rain toward Idaho because it pulls moisture from the Pacific Ocean, a component that the first low-pressure system this weekend will lack.
When will it warm back up in Boise?
If you’re worried that the cool weather will stick around, don’t fret.
Temperatures will quickly rebound as soon as the second low-pressure system continues eastward and out of Idaho.
“On Wednesday, our forecast high is 74 for Boise, and Thursday back up to 80,” Wojcik said. “Our normal high next week is 83, so we’re getting close to normal again.”
This story was originally published June 13, 2024 at 1:11 PM.
