Temperatures are expected to soar into the low 90s this week, further reducing mountain snowpack and increasing the likelihood of water restrictions as summer approaches, Douglas County Watermaster Dave Williams said today.
“The snowpack is not in very good shape, even before this forecasted heat bubble gets here,” he said. “What little there is left will probably suffer as a result of the heat wave.”
Douglas County already has had one bout with record heat this month. A second heat wave is forecast for Tuesday, Wednesday and Thursday, according to the National Weather Service.
There is no snow left at Diamond Lake, and the 42 inches at Crater Lake is fewer than half of the average for this time of year, Williams said.
Natural Resources Conservation Service hydrologist Melissa Webb said the snowpack is melting three to four weeks earlier than usual this year.
The early melt won’t affect the summer water supply as much as the lack of snowfall over the winter, she said.
“The Rogue and Umpqua basins didn’t get up to half of what they normally have, and that’s what is driving those volume forecasts to be so low for this summer,” she said.
The heat wave further reduced snowpack levels, Williams said.
“It has just compounded an already existing minimal situation,” he said.
The heat wave is forecast to begin Tuesday, peak Wednesday and begin to cool down Thursday.
A strong ridge of high pressure has settled in the area, clearing the skies and bringing dry air, weather service meteorologist Jay Stockton said today.
“When you have a very dry air mass with a lot of sunshine, it tends to lead to a lot of heating,” he said.
Roseburg set a heat record on April 30, reaching 92 degrees. The city tied the record of 92 degrees on May 1 before sharply cooling later that week.
Record highs for Roseburg are 89 degrees for today, 96 for Tuesday and 92 for Wednesday. The weather service is predicting to tie that record Wednesday, Stockton said.
The weather is supposed to cool after Wednesday, dropping to a high of 88 degrees Thursday and 77 degrees Friday.
Clouds should arrive Friday afternoon, and showers are expected this weekend with a high around 70, Stockton said.
Douglas Forest Protective Association is warning residents to use caution when burning debris with the warming temperatures.
Recent rains have brought flows above median levels for the past couple of days in the Umpqua River and the North and South Umpqua rivers, Williams said.
Roseburg has received .97 inches in May, a one-tenth of an inch above normal. Rainfall from the water year, which began Sept. 1, is 22.52 inches, 10.32 inches below normal.
Williams said he is hoping for a cool and wet summer.
“If we don’t get some summer rainfall and cooler temperatures this summer, then we’re likely to see considerably more and earlier regulation on the South Umpqua system in general,” he said.
He said it is likely water restrictions will be implemented on the main stem and tributaries of the South Umpqua River, on Calapooya Creek, the Deer Creek system and Elk Creek.
Most of Douglas County is currently in a severe drought, with a part of South County in a moderate drought, according to the U.S. Drought Monitor.
The water supply is starting to look like the summer of 2001, when a drought was declared, Williams said.
“I hope we don’t repeat that experience,” he said. “But we will see.”
• You can reach reporter Betsy Swanback at 541-957-4208 or firstname.lastname@example.org.