WEATHER DISCUSSION: A sustained breeze down the hillside moderates temperatures during Thanksgiving week. For now, wind gusts should stay below damaging levels. However, the strongest gusts will be Wednesday through Thanksgiving Day, where gusts of up to 50 MPH are possible for the Rocky Mountain front. Cold pools remain in valleys, including the Helena Valley, where temperatures are 15 to 25 degrees cooler than the rest of the state. A weak weather system is moving into Wednesday night from Tuesday night, which should help erode some of that cold air.
Travel weather looks mostly comfortable during Thanksgiving week. Light snowfall is possible Tuesday night into Wednesday over mountain passes including Marias Pass and Kings Hill Pass. Otherwise, the disturbance brings hit-or-miss showers to the central Montana plains. The larger area of concern for locations east of the watershed is gusty winds, which create areas of blowing snow and snowdrifts. Warmer temperatures will help reduce snowpack by the end of this week, however localized visibility is possible.
On Thanksgiving Day, which lasts into the weekend, a reinforced high-pressure ridge builds up in the region. Temperatures are warming above climatological averages for the first time in a few weeks, with highs in the 40s and 50s through Friday. A colder, snowier weather pattern looks set to return to the northern Rocky Mountains next week.
SUNDAY NIGHT: Partly cloudy. Overnight lows are in the low to mid 20s for central Montana, low to mid 10s for the Helena area and northeast Montana.
MONDAY: Mostly sunny and a bit windy. A sustained SW breeze of 10-15 MPH, at times gusting to 30 MPH. Highs in the upper 30’s for central Montana, with low 30’s for the Helena Valley and northeast Montana. Overnight lows in the mid-20s for central Montana, upper 10s for the Helena Valley, and 0s and 10s for northeast Montana.
TUESDAY: Mostly sunny, with increasing cloudiness west of I-15 in the afternoon. Breezy with a sustained SW breeze at 15-20 MPH, gusting at times to 35 MPH. Highs in the upper 30s and lower 40s. Mostly cloudy overnight with scattered rain and/or snow showers over the plains. Light snowfall over mountain passes with 1-4″ possible over Marias Pass. Overnight lows in the upper 20s and low 30s.
WEDNESDAY: Slight chance of scattered rain or snow showers in the morning, followed by partly cloudy skies and windy conditions. A sustained WSW breeze of 15-20 MPH, blowing up to 40 MPH at times. Highs in the low 40s. Partly cloudy overnight with temperatures falling into the high 10s and low 20s.
THANKSGIVING: Slightly cloudy, windy and dry. A sustained SW breeze of 15-25 MPH, at times gusting to 40 MPH. Highs in the low to mid 40s. Persistent partly cloudy skies overnight with temperatures falling in the low to mid 30s for central Montana, mid to high 20s for the Helena Valley and northeast Montana.
FRIDAY: Mostly sunny and windy. Highs in the mid to high 40s. Increasing clouds overnight with temperatures falling into the high 20’s and low 30’s.
SATURDAY: Slightly cloudy and windy. Highs in the low to mid 40s. Scattered rain and snow showers along the continental divide. Temperatures drop into the high 20s and low 30s overnight.
SUNDAY: Chance of rain and snow showers. Otherwise partly cloudy sky. Highs in the low 40s.