Don’t be spooked by the weather on Halloween, Boise, but beware of snow later in the week
Monday night may be filled with fear and fright, but if there’s one thing Boise residents don’t need to be scared of on Halloween night, it’s the weather.
Forecasts for the Treasure Valley, which show a slight chance of rain, may send a shiver down your spine, but there’s no need to run for cover. According to Jaret Rogers, a meteorologist with the National Weather Service in Boise, Monday evening into the night is forecast to be calm and above-average temperatures for trick-or-treaters.
“Monday is going to be the warmest day, definitely in the next seven days,” Rogers told the Idaho Statesman on Friday. “For trick or treating, that should be enough for 50s, and we’re probably going to top out in the lower 60s that day.”
The Weather Service forecasts 57 degrees for Boise at 7 p.m. on Halloween. Any chance of rain will come later in the night once everyone is back home, Rogers said, as the weather pattern gears up for a rainy week.
Early-season snow?
But almost like flicking a switch, as soon as the clock ticks over from October to November, rainy weather with the potential for snow will move into Boise.
After a blocking pattern that had been sitting over the Northwest for the summer broke down last week and allowed cold air and moisture to flow into the region, the Treasure Valley has enjoyed a few calmer days.
But with so much cold air bottled up over Canada now rushing southward, the high-pressure system keeping Boise dry will quickly be overrun, allowing rain and snow back into the Gem State.
“That cold air is finally starting to move southward and progress more eastward. So really, the whole jet stream itself is shifting southward into the northwest United States,” Rogers said. “And with that, we’re starting to see a more active storm pattern, so we get more chances for rainfall.”
Starting late Monday night, Rogers expects about half an inch of rain to fall in the Treasure Valley. But rain isn’t the only thing that’ll be dropping from above.
The Weather Service forecasts a chance of snow on Wednesday and Thursday as colder air sweeps over the region. Rogers said that if it does snow, Boise can expect less than an inch.
“I’d say less than an inch is probably a pretty safe bet at this point,” Rogers said. “It’s always hard in these situations, because it’s very localized sometimes, so sometimes you can get a surprise-type event. But the signal right now is for very light amounts, if any accumulations at all.”
Boise averages its first measurable snowfall of the year on Nov. 22. If Boise records measurable snowfall on Wednesday (Nov. 2), it’ll be the earliest snowfall since Oct. 29, 2019, and before that, on Oct. 27, 1971.
