Mother Nature likes April Fools’ Day. Sun and 70s to be followed by thunderstorms, snow
It wouldn’t be spring in Boise if the weather weren’t capable of turning on a dime.
And wacky weather is precisely what will happen this week in the Treasure Valley.
The National Weather Service in Boise forecasts a beautiful start to the week, with temperatures soaring to 71 degrees Tuesday and 72 degrees Wednesday. Those temperatures will equal the warmest weather Boise has seen in 2024, matching the brief “false spring” that Idahoans enjoyed in mid-March.
Unfortunately, the warm start to April will be another instance of what Weather Service meteorologist Josh Smith described as a “typical spring.” Rain and thunderstorms will move into the area by Wednesday afternoon, and temperatures will drop back into the 50s by the weekend.
Here’s what to know:
A hint of spring in Boise
Residents woke up Monday morning to clear skies. A high-pressure ridge, typically accompanied by calmer weather, brought temperatures between 6 and 10 degrees warmer than average for early April, with highs in the mid-60s. The area of high pressure won’t keep Boise from plummeting back to the upper 30s and low 40s overnight, but that sort of fluctuation is common.
Boise experiences such fluctuations because of the low amount of moisture in the air, partly due to the mountain ranges to the west and the city’s altitude (2,730 feet).
By Wednesday afternoon, a new system will move in and throw off Boise’s serene weather.
“This is a pretty typical springtime pattern for us,” Smith told the Idaho Statesman. “So we’re getting these lows and troughs followed by a couple of days of drier, warmer temperatures, and then we get another cold trough.”
Thunderstorms and snow
If there’s one thing weather enthusiasts can look forward to during spring, it’s a chance of thunderstorms finally returning to the Treasure Valley. A cold front moving into the area Wednesday afternoon, Smith said, will be accompanied by wetter and stormier weather.
“I really do think we could see some thunderstorms on Wednesday,” Smith said. “Right now, we’re predicting about a 15% to 20% chance. It’ll be more like Wednesday afternoon and evening. And that’s going to be just ahead of a cold front that’s going to be moving in.”
The Weather Service predicts that between two-tenths and a half-inch of rain could fall between Wednesday afternoon and Thursday evening. There is a 70% chance of rain Thursday and Friday before precipitation chances drop to 20% for the weekend.
Temperatures also will be dropping. A high of 51 is expected on Saturday, with the low temperature at 33 degrees.
With those lows around freezing, there is a slight chance that rain could turn into snow, even in the valley. But more than likely, the snow will be contained to the mountains.
“We don’t really have any chance of snow here … until maybe Saturday morning. That’s when the coldest air tries to come in,” Smith said. “Looks like the majority of it is going to be above 5,500 feet. We haven’t really worked out how much (will fall) yet.”
A mostly warm and dry April
It’s generally forecast to be a rainy and cold start to April, but Smith doesn’t expect the rest of the month to follow suit.
“With this trough, it looks like it’s going to be over us through next weekend,” Smith said. “I’d say the first part (of the month) is going to be probably below-normal temperatures, but we’re going to be trending to be above normal here for the mid-period to later part of the month, then it looks like we’ll transition to maybe a less active pattern.”
The Climate Prediction Center, an arm of the National Oceanic and Atmospheric Administration, forecasts that in April, Boise will have a 55%-60% chance of above-average temperatures.
What does that mean in layman’s terms?
Boise typically enjoys an average high temperature of 62.3 degrees in April and an average precipitation of 1.23 inches. Based on the CPC’s forecast, Boise residents can expect to enjoy average temperatures of at least in the mid-60s and rainfall to be hard to come by after this week.
