Steamboat Springs — Improbably, after a winter of sub-par snowpack, the rain-swollen Yampa River set a new record Wednesday for May 6 streamflow at the Fifth Street Bridge in Steamboat Springs.

The river was flowing at 2,970 cubic feet per second at 4:15 p.m. Wednesday, according to gauges managed by the U.S. Geological Survey. That’s well above the previous record of 2,790 cfs, which was recorded in 1920. Records have been kept at the Fifth Street Bridge for 105 years.

Just eight blocks downstream, below Soda Creek, the river was flowing at 3,370 cfs late Wednesday afternoon to the delight of kayakers romping in Charlie’s Hole. That, too, was a record, but based only upon six years of record keeping.

While there remains significant snowpack, albeit below average, on Rabbit Ears Pass, it is apparent that it was rain, not heat, that brought the river up.

National Weather Service meteorologist Joe Ramey pointed out that snowpack in Northwest Colorado was at 55 percent of average to begin the month of May and ranged upward to 65 percent in the upper Colorado River Basin.

Ramey said the long-range precipitation outlook for the the Grand Junction forecast area, which includes Routt and Moffat counties, was for increased chances of wetter than normal conditions this month. And that forecast came true overnight Tuesday into Wednesday in Routt County.

Rain gauges on the fringes of Steamboat showed anywhere from .49 to .84 inches Wednesday morning, but the greatest precipitation amounts were in South Routt, where as much as 1.07 inches of rain fell in Stagecoach and .96 inch fell five miles south of Yampa in the river’s headwaters.

Moffat County did not receive the benefits of the drenching rain overnight. A weather station almost five miles west, northwest of Craig recorded a trace of moisture, and another station 1.2 miles east and south of the city recorded .04 inch. There was more rain in far western Moffat, with .23 inch falling in the vicinity of Dinosaur.

North Routt didn’t receive nearly as much rain — a weather observer in Clark recorded .7 inch — and those numbers were reflected in streamflow in the Elk River near its confluence with the Yampa. The Elk was flowing at 1,790 cfs Wednesday afternoon, well above the median of 1,610 cfs, but less than half the record for the date.

Lower Elk River Valley rancher Mary Kay Monger said Tuesday her ranch had received about a quarter of an inch of rain as of Wednesday morning.

“We watched the storms, and we could see it was pouring in town,” Monger said. “We drove into town, and it was raining, but on the way back, as soon as we passed Sleepy Bear, the roads were dry.”

She confirmed the grass hay on the ranch has begun to grow, and this month and next are the season for optimal growth. However, there’s always a chance the new grass will get knocked back by a cold spell.

“If it gets down in the 20s and freezes, it stunts the grass,” she said.

The Weather Service doesn’t expect the Mongers’ hay to be nipped by frost Wednesday night, but the forecast for the lower Elk River Valley indicates it will be colder Sunday night, when the thermometer could read in the upper twenties.

The summit of Mount Werner, above 10,000 feet, is another story. It could see a half-inch of snow by morning, according to the Weather Service, and snow remains in the forecast for the higher reaches of the Steamboat Ski Area through the weekend.

There remains a chance of rain in Steamboat’s forecast Thursday and Friday with highs in the upper 50s both days.

To reach Tom Ross, call 970-871-4205, email tross@SteamboatToday.com or follow him on Twitter @ThomasSRoss1