OREGON STATE UNIVERSITY

2013 Weather Roundup: Wettest September doesn’t offset dry year

12/27/2013

CORVALLIS, Ore. – The weather couldn’t seem to make up its mind what it had in store for Oregon in 2013. The state saw drought and the wettest September on record, as well as withering heat and sub-zero temperatures in the Willamette Valley.

An early December storm dropped several inches of snow on Corvallis, yet snowpack levels in the nearby Cascades are well below normal.

The United States drought monitor listed 100 percent of the state as at least abnormally dry in 2013, according to Kathie Dello, deputy director of the Oregon Climate Service at Oregon State University.

“All of Oregon is listed as dry, but southern Oregon has been historically dry in 2013,” said Dello, “and Medford and the southern coast have a chance to have their driest year on record.” As of mid-December, the Medford Airport had received just 8.97 inches of precipitation; the record dry year was set 1959 with 10.42 inches. The North Bend Airport was nearly five inches short of its driest year on record.

Despite abnormally dry conditions throughout Oregon for most of the year, it was soggy September. The month began with an enormous thunder and lightning storm that covered much of the state, triggering hundreds of fires and contributing to what Dello called a “bad wildfire year in Oregon.” The storm also dumped nearly three inches of rain on the southern Willamette Valley.

Near the end of the month, the remnants of a typhoon named Pabuk swept into the state and hammered western Oregon. Some precipitation monitors near Coos Bay recorded as much as 5.77 inches of rain on Sept. 29.

“Unfortunately, the September precipitation was not enough to offset dry conditions the rest of the year,” Dello said. “When it’s dry, that’s not how you want to receive you rainfall – in two major events. Rivers get only temporary relief and the torrential downpours can cause damage to agricultural crops.

“It’s better to have smaller, sustained rainfall events than a couple of major outbursts,” she added.

Oregon experienced a comparatively warm summer with more days than usual when temperatures exceeded 90 degrees, including the end of June and in September between the two rain events. On the other end of the spectrum, temperatures in early December plummeted to near-record lows as an Arctic front moved in.

Eugene, for example, recorded its second coldest day on record when the mercury hit minus-10 degrees on Dec. 8. Interestingly, it was not the coldest Dec. 8 on record as the all-time record low for Eugene of minus-12 degrees also occurred on Dec. 8 in 1972.

The December Arctic front hit the Corvallis area the hardest, though the weather station north of town at Hyslop Farm officially recorded just 4.5 inches of snow. Much of the area received 9-10 inches of powdery snow, forcing weeklong shutdowns of many schools and activities.

Dello said the lack of official weather recording stations in Oregon is one reason volunteers are needed for a statewide network that uses Oregon citizens to collect local data on rain, snow and even hail. The program is part of the national Community Collaborative Rain, Hail & Snow Network, or CoCoRaHS.

The Oregon Climate Service, which is part of OSU’s College of Earth, Ocean, and Atmospheric Sciences, coordinates the Oregon network. Persons interested in volunteering should go to the CoCoRaHS website at http://www.cocorahs.org/ to sign up.

“Data collected by volunteers throughout the state help provide us with much more accurate data, which leads to better precipitation maps and over the long haul, more accurate forecasting,” Dello said.

Among other highlights of Oregon’s 2013 weather year:

  • As of mid-December, the Eugene Airport had recorded 21.04 inches of precipitation; the record low was set in 1944 with 23.26 inches. Records there date back to 1911.
  • The Salem Airport had logged 23.41 inches through mid-December. The driest on record, dating back to 1940, is 23.77 inches.
  • The North Bend Airport is well ahead of the record dry year, set in 1976 with 33.52 inches. Through mid-December, the station had only recorded 28.67 inches. Records date to 1928.

Dello frequently provides weather facts and historical data via Twitter at: www.twitter.com/orclimatesvc.

College of Earth, Ocean, and Atmospheric Sciences

About the OSU College of Earth, Ocean, and Atmospheric Sciences: CEOAS is internationally recognized for its faculty, research and facilities, including state-of-the-art computing infrastructure to support real-time ocean/atmosphere observation and prediction. The college is a leader in the study of the Earth as an integrated system, providing scientific understanding to address complex environmental challenges