Sudden temperature drop, rain, possibly the first fall frost. Weather change is coming
The Treasure Valley this week is expected to get its last feel of really warm temperatures for the year, as a low-pressure system from the Gulf of Alaska moves through Idaho on Wednesday and ushers in fall weather.
High temperatures are forecast to drop 20 degrees from Tuesday to Wednesday. The low-pressure system is also likely to bring rain and possibly the first frost of the season, according to the National Weather Service in Boise.
Here is what the Weather Service forecast for Boise and Treasure Valley residents this week.
Alaska cold drifts into Idaho
The low-pressure system affecting Idaho this week is coming from the Gulf of Alaska, bringing cold air with it and likely blowing away warmer temperatures for the rest of the year.
The system is expected to arrive Wednesday, and the changes will be felt immediately. The high temperature was expected to drop from 82 degrees Tuesday to 62 degrees Wednesday. For the rest of the work week, the high temperatures are forecast to be just 54 degrees Thursday and 55 degrees Friday.
Moderate rain is likely to tag along with the pressure system at around noon Wednesday, with light wind gusts up to 8 mph from the west.
“By Thursday, we have a high forecast in the mid-50s, which is about 10 degrees below normal. So, it’s quite the transition,” said Dave Groenert, a meteorologist with the National Weather Service in Boise. “It’s typical during these shoulder seasons, where you start changing seasons. We will get these fronts coming through here, and we’ll go from kind of one extreme to another.”
There is a chance for the showers to continue into Thursday.
First frost of the season?
Groenert also warns that residents can expect a frost Friday morning, and to prepare accordingly with plants that are susceptible.
The low temperatures are forecast to be in the 30s Thursday, Friday and Saturday, and could hit freezing overnight one of those days.
“It’s right around that time of year where we get our first frost freeze and so would be our first one of the fall,” Groenert said.
He said high temperatures are unlikely to reach the mid-70s during the remainder of the year.
This story was originally published October 15, 2024 at 4:00 AM.
