Fluctuating air quality in valleys today, expect deterioration through Saturday

Strong inversions forming over valleys
Posted at 3:37 PM, Feb 20, 2020
and last updated 2020-02-20 17:37:02-05

MISSOULA — Air quality will fluctuate between good and moderate today.

We have already seen areas like the Bitterroot Valley and Butte hit the ‘moderate’ mark before returning to ‘good’.

High pressure continues to strengthen the inversion layer that will continue to strengthen over Western Montana valleys through Saturday.

Otherwise, expect plenty of sunshine and bluebird skies to also remain in the forecast through the beginning of the weekend.

As we head into the weekend, our next system will already be on its way here.

Another system from the northwest moves in bringing slightly cooler temperatures- but mainly a lot more precipitation.

Rain and snow move in on Sunday afternoon. Rain will make it to valleys as snow stays in the upper elevations (mountains and mountain passes).

Rain will turn to snow in valleys overnight Sunday into Monday.

This system will be short-lived, but we can expect some periods of heavy rain and snow.

Temperatures take a drop from the 40s Sunday afternoon to the mid to upper 30s on Monday, so it isn’t a huge drop, but it still kicks us to below-average.

Isolated chances of rain and snow remain in the forecast through midweek next week, but we most likely will see more clouds than anything.

So, high pressure keeps us warm and dry until Saturday, and then we track those changes moving in for the end of the weekend/beginning of next week.