Hi-Line can expect colder, wetter winter
While fall activities are still set for the weekend, north-central Montanan's may want to remember their booties, because the forecast calls for a preview of the upcoming winter.
While the National Weather Service is calling for a warmer spell Wednesday and Thursday — with highs in the low 50s — a taste of the colder forecast for the weekend even seen today, with some flakes falling in Havre this morning.
The forecast cold weather and likely snow is expected to shift back to more normal weather for the region early next week, but it just is a preview for what is expected later in the season, with cold temperatures and above-normal snow expected from December through February.
The weather service reports that a winter-like system will move into the region over the weekend, with highs forecast in the 30s for Friday, Saturday and Sunday, with a likelihood of snow in the region Friday and Friday night. That could amount to 1-inch to 4-inch accumulations in low lying areas and 4 to 8 inches in the mountains.
Lows are forecast in the low to mid-teens.
The highs are expected to be back in the 40s by Monday, but with colder temperatures and wet weather expected next month.
Graphics based on data taken from National Weather Service
The graphics above show the forecast weather trends for December through February, with cooler, wetter weather than average through the northern part of the United States and warmer, drier weather in the south-central portion.
A strong La Niña system in the equatorial Pacific, with cooler-than-normal ocean temperatures, is expected to bring cooler, wetter weather to the Pacific Northwest and along the northern part of the United States. While the exact weather cannot be predicted, cold and snow is expected through Washington and Montana through the Great Lakes region from December through February.
The system is expected to continue the hotter, drier-than average weather in the south-central part of the country, likely to continue the drought conditions in Texas, Oklahoma, New Mexico and some surrounding states.
The weather service reports that weather conditions could lead to another spring with flooding in the Northern Plains.
"The evolving La Niña will shape this winter, " said Mike Halpert, deputy director of the National Oceanographic and Atmospheric Administration's Climate Prediction Center. "There is a wild card, though. "
Halpert said it is impossible to predict exactly what will happen due to other variables, particularly activity in the Arctic Ocean. That activity could overwhelm the La Niña pattern, he said, adding that in its negative phase the Arctic activity pushes cold air into the United States from Canada. That oscillation led to severely cold and snowy conditions in 2009 and 2010.