The snow season saved its best for last this year, boosting snowpack in the reservoir-rich Colorado River basin from a woeful 72 percent of average on Feb. 2 to a promising 93 percent Tuesday.

From Saturday to Tuesday alone, the percentage against the 30-year average jumped by 7 percentage points.

“It’s not done yet,” state climatologist Nolan Doesken said Tuesday afternoon. “What we got yesterday and last night was just sort of a precusor to a big system that should arrive in the mountains Wednesday.”

Areas that saw more than 2 feet of very wet snow Sunday and Monday could pick up as much as 18 more inches Wednesday, he said.

“It’s made a super strong comeback in the last four days,” Doesken said of the state’s snow supply, which provides most of the water Colorado needs for household use, irrigation and recreation all year long.

Denver could see up to 5 more inches of snow Wednesday, and a 40 percent chance of snow is in the forecast for Thursday, according to the National Weather Service.

The temperature in the city Wednesday is expected to peak at 30 degrees, followed by a forecast high of 34 Thursday, before temperatures rebound to 48 degrees Friday and into the mid-50s for the weekend and Monday.

Mage Hultstrand, assistant snow survey supervisor for the Natural Resources Conservation Service in Lakewood, said the high percentage of normal is a bit misleading but in a good way.

Colorado’s snowpack typically begins to melt on April 10, but a week later this year, the snowpack is still mounting, so the percent of average looks higher measured against past numbers that typically are shrinking this time of year.

The longer the snow stays, the better. A slow melt would allow the thawing ground in the mountains and foothills to absorb more of the moisture to green up the landscape more nicely, which helps deter spring fires. After one of the driest and warmest Marches on record last year, Colorado was pummeled by huge wildfires, and all but two counties were deemed crop-disaster areas.

The snowpack accumulating now could come down the mountains in a gush as the weather warms later this spring.

“If this holds out, it’s going to be really good for the rafting industry,” Hultstrand said.

Denver Water is keeping a close watch on the improving conditions. The state’s largest water utility already announced restrictions on lawn watering this summer, but it will be flexible if conditions allow it, spokeswoman Stacy Chesney said.

“It’s too early to make that call.”

Denver Water’s 10 reservoirs haven’t been full since July 2011, so there is a lot of ground to make up for last year, said Bob Steger, the utility’s manager of raw water supply.

The 3 to 4 feet of snow this week is welcome news, he said, but it’s not the final word on the filling reservoirs and summer watering.

“We don’t know how much of that snow is going to be water in our reservoir,” Steger said.

“Maybe May and June will be very dry. We just have to continue to monitor our water supply very closely.”

Joey Bunch: 303-954-1174, jbunch@denverpost.com or twitter.com/joeybunch