Temperatures remain warm across the region, reaching the 40s and 50s over the past few afternoons. This continued pattern and incoming rain have us concerned about flooding in areas recently hit hard by winter weather.
Tropical Pacific moisture is currently streaming into Canada, but will take a southerly turn and end up moving over Montana Monday afternoon though Wednesday. Areas from Lolo Pass to the Canada border along the Idaho state line could see a couple of inches of rainfall during this time period as the rain/snow line will rise above 6000 feet. Heavy rainfall amounts are also possible in the Glacier, Mission, Swan, and Whitefish ranges over the next three days. Combine that with between a quarter-inch to one inch of rain in valleys north of I-90 and you have quite a bit of water in a short time period for this area.
The rain will be falling on melting snow, which may speed up the melting that will be going on in the area this week after last weeks' winter storms. With up to 11 inches of snow on the ground around the Flathead Valley, that melting could produce as much as an inch of standing water. When you combine all of these factors together, it's a setup that cold lead to some flooding.
Thus, over the next few days people in northwest Montana should expect standing water on roads, an enhanced risk of avalanches and rock slides, and possible flooding of basements and low-lying areas as well as swollen creeks and streams. Other parts of our area will also see melting snow, some standing water, and larger stream flows, but the flood risk is not as high.
To help protect your home from flooding, make sure to clear drain pipes and downspouts and shovel snow away from the home's foundation.
Overnight lows will stay near or a bit above freezing to start the week with highs in the 40s and 50s. Bozeman has a chance at 60 on Wednesday. Rain will mainly stay around the Kalispell and Missoula areas but Butte and Bozeman will have better chances of rain Tuesday and Wednesday.
Change comes Wednesday night into Thursday with a cold front that should provide us a chance for a few snowflakes, even in the valleys. We will warm right back up again Thursday and Friday before anther front cools us back down again Friday night.