Wintry weather to follow warm weekend

According to the National Weather Service’s Missoula Forecast Office, “A few places will be getting close to record high temperatures by Thursday and Friday,” but “Confidence is steadily increasing with a big pattern change occurring next week.” 

A cold air mass moving into the Northern Rockies is expected to result in “widespread snow” down to most valley floors around the middle of next week, according to the agency. While temperatures are forecast to be 15–20 degrees Fahrenheit warmer than normal late this week and into the weekend, next week’s temps could drop to 10 degrees below normal for late October. 

On average, Missoula sees its first measurable snow accumulation — measured by NWS at Missoula International Airport — around Oct. 30. The earliest snow accumulation on record in Missoula, according to agency records dating to the late 1800s, was Sept. 15, in 1965. The latest was Dec. 24, in 1904. Last year, the Missoula Valley floor first recorded measurable accumulation on Nov. 5, although the surrounding mountains were coated white by late October. 

As of Wednesday, NWS predicted snowfall amid temps in the upper 30s to low 40s around Oct. 24–26, or Tuesday to Thursday next week. But before that, things will feel almost summer-like. 

The agency predicted a high of 74 degrees with sunny conditions in Missoula on Thursday and Friday. The historical average high temperature for Oct. 19 is 54 degrees, and for Oct. 20 is 53 degrees. The record high in Missoula for Oct. 19 is 74 degrees, set in 2017. For Oct. 20 it’s 72 degrees, set in 1897. 

Those possibly record-matching or -breaking days were forecast to be followed by 72 degrees and some clouds on Saturday. The norm that day is also 53 degrees; the record high is 80 degrees, in 2003. Then it’s a predicted 65 degrees with a chance of rain on Sunday, 55 degrees and rain Monday and 50 degrees and rainy on Tuesday. Overnight lows were forecast in the mid-40s before dropping to the upper 30s by Monday night. 

Temperatures could be even warmer in Hamilton, with forecast highs of 76 degrees Thursday and Friday, followed by 73 degrees Saturday and 67 degrees Sunday. But Hamilton too will turn colder and rainy by early next week, with a high of 54 degrees Monday and 50 degrees Tuesday, with rain expected both days. Lows in Hamilton were forecast in the mid-40s this week before dropping to the mid-30s by early next week. 

Kalispell was expected to be slightly cooler, but on a similar trajectory of warm and sunny to cool and rainy. NWS predicted a high of 69 degrees Thursday, 68 degrees Friday and 65 degrees Saturday, all with sunny conditions. Then it’s an expected 61 degrees with a chance of rain Sunday, 53 degrees and rain Monday and 46 degrees and rain Tuesday. Lows in Kalispell were forecast to drop from the low 40s late this week to the mid-30s by early next week.

Libby was forecast to see a similar weather shift in coming days, but not as cold as some of its northwestern Montana neighbors. NWS predicted highs of 75 degrees Thursday, 74 degrees Friday and 72 degrees Saturday, with some clouds Saturday after multiple sunny days before. After that, the agency predicted a high of 66 degrees and possible rain Sunday, 59 degrees and possible rain Monday and 50 degrees and likely rain Tuesday. Lows there will shift from around 40 degrees late this week to the mid-30s early next week.