Medford is less than two weeks away from ending the driest calendar year on record with no gully-washer forecast for the foreseeable future, thanks largely to weather patterns now favoring arctic blasts.
The last two weeks of December are historically the wettest of the year, but not even the normal rainfall of 1.28 inches between Thursday and New Year's Day would keep 2013 from the dubious distinction as the driest in Medford since records were first kept here in 1911.
As of Thursday, the National Weather Service had measured just 8.97 inches of rain since Jan. 1. The current record of 10.43 inches came in the uber-dry year of 1959, and the second driest was 10.71 inches in 1985, according to the National Weather Service. The average is 18.35 inches in a year at the Medford airport.
Similarly, Keno is set to fall short of its all-time low rainfall record of 9.82, which also was set in 1959, the weather service reports. Yreka, Calif., is just a hair above its past record of 8.04 inches of rain set there in 1949.
"It doesn't look like there's any really significant precipitation heading our way, so the records could be in jeopardy," says weather service meteorologist Marc Spilde in Medford.
"For Medford and Keno, it definitely looks like they're going down," Spilde says.
Most Oregon municipalities are flirting with similar low-rainfall calendar years, in part because a dry fall has been followed by a cold and dry November and December that saw record lows in places such as Eugene and Lakeview.
More typical fall patterns see storms generating around Hawaii and pushing north and east, hitting Southern Oregon with the relatively warm and wet storms that generate valley rain totals and add to mountain snowpacks.
Those occur because of tropical ocean temperatures that usually trigger the El Niño or La Niña phenomenons, says Steve Piece, a Pacific Northwest weather expert and founder of Northwest Weather Consultants in Vancouver, Wash.
El Niéos bring warmer and drier winters to the Pacific Northwest. La Ninas bring cooler and wetter weather, Pierce says.
But this year's tropical water temperatures are right at normal and, therefore, not generating El Niño or La Niña, he says.
"I like to call it 'La Nada,'" Pierce says.
High-pressure systems instead have built along the Eastern Pacific, shutting off the jet stream and forcing arctic air masses that have left the region very cold and relatively dry, Pierce says.
"It puts us into this arctic blast," Pierce says. "This is the most significant arctic outbreak since 1990."
The weather service's rainfall data for Yreka dates back to 1893. The Keno records go back to 1927.
The inland rainfall shortage is not as prevalent along the Southern Oregon coast. Bandon, where rainfall data stretches back to 1897, has recorded 35.37 inches of rain so far this calendar year, ranking third of all time in lows.
Bandon's record low was 32.27 inches in 1976, records show.
Reach Mail Tribune reporter Mark Freeman at 541-776-4470, or email at email@example.com.