'Bomb cyclone' over the Pacific roils Rogue Valley weather

Jan. 5—A storm system sparked by offshore hurricane-force winds began making its way through Southern Oregon at midday Wednesday, leaving in its wake a trail of downed trees, traffic hazards and power outages in the Rogue Valley and causing hazards ranging from snow flurries to avalanche warnings in Northern California.

Rogue Valley International-Medford Airport lost power for approximately 90 minutes Wednesday, and the Jackson County Sheriff's Office and roads crews responded to more than a dozen downed trees and traffic hazards as of midday Wednesday caused by a windstorm expected to last through Thursday afternoon.

The National Weather Service issued a high wind warning for south Jackson County residents in upper elevations and issued a wind advisory for locals on the valley floor through 4 p.m. Thursday, according to meteorologist Brian Nieuwenhuis with the National Weather Service in Medford.

The advisory stems from a low-pressure storm system sparked by bombogenesis or a "bomb cyclone" off of the Northern California and Southern Oregon coast, according to Nieuwenhuis and info from the National Oceanic and Atmospheric Administration. The storm system is responsible for heavy winds and precipitation impacting large portions of central and Northern California, as well as winds above the surface in the Rogue Valley that Nieuwenhuis described as "the strongest we're seeing in 30 years."

"It's an extremely large weather system," Nieuwenhuis said. "It's well offshore, but due to its size, the impacts are being felt pretty far from it."

Shortly after 1 p.m. Wednesday, the weather service recorded wind speeds as high as 99 mph at Acorn Woman Peak near Jacksonville, formerly known as Squaw Peak, but those wind speeds haven't made it down to the valley floor. The strongest wind recorded at the weather station near the Medford airport was 54 mph.

It still was a strong enough wind to take out the Medford airport's power for approximately 90 minutes, according to interim Airport Director Amber Judd.

The airport has a power backup system that worked properly during the outage, which was reported about 11:30 a.m., according to Judd, but it "doesn't cover 100% power."

"It doesn't necessarily cover the baggage handling system — we were moving bags by hand," Judd said.

Although the baggage system outage caused delays, Judd said she was aware of only one flight cancellation, which may have been because of the flight's "destination weather," she added.

Airport power was restored at about 1 p.m. When reached shortly before 2 p.m. Wednesday, Judd said, "we are roughly back."

"Planes are moving," Judd said. "Any other delays are probably just regular weather delays at this point."

At 3 p.m. Wednesday, Pacific Power's outage map showed 2,350 Southern Oregon customers without power. For the latest updates on progress repairing known outages, see pacificpower.net/outages. To report an outage, call 1-877-508-5088 or text "OUT" to 722797.

Pacific Power recommends locals be prepared for outages with an "emergency outage kit" containing: flashlight, battery-operated radio and clock, extra batteries, nonperishable foods, a manual can opener, bottled water and blankets.

Anyone who spots a downed power line or utility line should stay away from it, call Emergency Communications of Southern Oregon dispatchers at the nonemergency line of 541-776-7206, then call Pacific Power at 1-877-508-5088. Never drive over downed power lines.

Jackson County sheriff's deputies responded to multiple hazards and emergencies sparked by the windstorm in Gold Hill, Medford, Trail and along Butte Falls Highway Wednesday afternoon, according to an advisory issued by the sheriff's office, and road crews responded to "more than a dozen trees down all around the county."

A downed power line at No Name Lane near Trail sparked a grass fire at 12:39 p.m. that Jackson County Fire District No. 4 crews swiftly knocked down, according to the sheriff's office. Once the fire was extinguished, Pacific Power crews took over to fix the line.

Other incidents sheriff's deputies responded to Wednesday included a fallen tree on North River Road near Gold Hill that took out a utility pole at 11 a.m., a low-hanging utility line near the intersection of David Lane and Payne Road near Medford at 11:34 a.m., and a fallen tree that downed Hunter Communications fiber optic lines near Butte Falls Highway and Highway 62, according to the sheriff's office.

Sheriff's officials expect more downed trees and power lines during the windstorm. The National Weather Service high wind warning predicted wind speeds between 35 and 45 mph and gusts of up to 65 in the southern portion of Jackson County.

In other parts of the county, including the Medford area, the wind advisory lasting until 4 p.m. Thursday called for winds of 25 to 35 mph and gusts of up to 50.

Medford Public Works crews Wednesday responded to 19 downed trees and tree limbs within city limits and corrected wind-related issues at three intersections Wednesday, according to numbers provided by city of Medford spokeswoman Kristina Wilson. To report down trees in Medford roads and public rights of way, call Public Works at 541-774-2600. (Updated)

The same storm system is causing heavy precipitation in Central and Northern California, but much of that wet weather is shed as the storm travels through mountainous regions into Southern Oregon.

"We get a lot of what we call rain shadowing," Nieuwenhuis said. "That's why they're getting so much rain out of it, but we're just getting the wind out of it."

The storm system brought hazardous travel conditions to Northern California, including snow and strong winds impacting visibility Wednesday.

The Medford weather station tracks conditions in the Mount Shasta, California, area. Nieuwenhuis said snow levels are expected to improve in the area Thursday, but some roads could still be impacted through Thursday afternoon.

An avalanche warning is in effect on Mount Shasta through Sunday — particularly at elevations above 7,000 feet.

In the Rogue Valley, the snow level is trending up from about 4,000 feet Wednesday to between 5,000 and 6,000 feet Thursday.

After the windstorm passes, the forecast calls for rain showers and temperatures in the 40s and 50s along the valley floor, according to Nieuwenhuis. He estimates another half-inch of precipitation will fall in Medford Thursday night through Sunday.

Some extended forecast computer models are predicting rain through the entire month of January, according to Nieuwenhuis. Behind the prediction is a large "upper-level trough" sitting over Russia's Kamchatka Peninsula.

"It's kind of like a cannon that's just firing off (weather) systems across the West Coast," Nieuwenhuis said, describing new systems bringing wet weather every day to two days.

As of levels recorded shortly after 1 a.m. Wednesday, Medford had recorded 6.59 inches for the water year beginning Oct. 1. That's up 1.81 inches from the 4.78 inches recorded Dec. 29 — before wet weather from an "atmospheric river" passed through the valley — but it's still down 14% from the 7.65 inches considered normal for the water year.

Roseburg is 22% below normal at 10.65 inches, and the city of Mount Shasta, California, is 28% below normal at 9.28 inches. KIamath Falls is 12% above normal at 4.55 inches, and Alturas, California is 29% above normal at 4.76 inches.

The extended rain forecast is welcome news but after back-to-back droughts, but local reservoirs are far from full.

Fish Lake is 39% full, Agate Lake is 24% full, Fourmile Lake is 20% full, Howard Prairie and Emigrant lakes each are 11% full and Hyatt Lake is 8% full, according to the U.S. Bureau of Reclamation data recorded Tuesday.

Lost Creek Lake is 42% full, and Applegate Lake is 21% full, according to U.S. Army Corps of Engineers data.

Reach web editor Nick Morgan at 541-776-4471 or nmorgan@rosebudmedia.com. Follow him on Twitter @MTwebeditor.

Update Jan. 5: Added Wednesday Medford Public Works wind-related calls for service numbers provided by the City of Medford.