Area streams and rivers are expected to surge this week as record high spring temperatures bake the Northern Rockies for a few more days.

The National Weather Service in Missoula warned Tuesday that Montana mountain ranges are quickly shedding snow at mid and upper elevations under the relenting warmth.

“Steady rises on area streams and rivers will continue, with all waterways running colder and faster than in previous days,” the Weather Service stated in its hydrologic outlook.

The Flathead River at Columbia Falls was projected to crest at 11.9 feet by Saturday morning. The river was at 6.5 feet on April 29 prior to the arrival of the heat wave. Flood stage at Columbia Falls is 13 feet.

The Swan River at Bigfork will crest at about 5 feet on Sunday, below the 6.5-foot flood stage, while the Stillwater River at Lawrence Park in Kalispell will top off at 4.76 feet, well short of the 7.5-foot flood mark.

Kalispell set record high temperatures Sunday and Monday, with the weather station at Glacier Park International Airport hitting 82 and 86 degrees, respectively. Yet another daily record was predicted for Tuesday.

Normal high temperatures in Kalispell for this time of year are in the low 60s, with lows in the 30s.

The warmth is expected to continue through Thursday before a cold front ushers in widespread rain showers. Some areas in Northwest Montana could get an inch of precipitation.

Meanwhile, mountain snow levels could drop as low as 6,000 feet Friday night, bringing raw and chilly conditions in the backcountry.

Valley temperatures will be much cooler by the weekend, with highs only reaching the 50s and lows in the 30s.

The extended forecast remains unsettled.

“Back to spring conditions in the valleys with temperatures below average and winter in the mountains at times,” the Weather Service stated in its Tuesday outlook.