Date:
Thursday, May 15, 2008
Contact:
Alice Fiman, WSDOT Communications, (360) 705-7080 (Olympia)
Mike Westbay, WSDOT Communications, (509) 728-4712 (Yakima)
Jeff Adamson, WSDOT Communications, (509) 667-2815 (North Cascades)
Sylvia Ross, WSDOT Communications, (360) 905-2058 (Vancouver/Spirit Lake Highway)
Patrick Conrad, WSDOT Communications (206)437-6314 (Seattle)
OLYMPIA – Warm temperatures expected this weekend have WSDOT experts monitoring Washington’s mountain pass highways for avalanche control work. The Northwest Avalanche Center has also issued warnings for back country areas.
WSDOT crews who recently cut through snow pack to open SR 20 (North Cascades Highways) and SR 504 (Sprit Lake Memorial Highway) are now watching those roadways for weakness in snow walls.
Due to avalanche threat and unstable snow walls, crews closed the North Cascades Highways (SR 20) between Diablo and Silver Star (nine miles west of Mazama) at 12:30 p.m. today (Thursday, May 15). Crews will revaluate the North Cascades on Monday morning. If crews find significant slides on Monday, it could take several days to clean up. WSDOT opened North Cascades Highway (SR 20) May 1.
The avalanche chutes between Diablo and Silver Star that are full and becoming more unstable by the hour as the temperature continues to climb.
This North Cascades Highway situation is highly unusual. Traditionally, the chutes aren’t still full by this time of year. This spring has been so cold that, while full, the chutes have remained stable. This 30-plus degree rise in temperature heats up the top layer of snow, making it heavier and creating a slip-plane with the layer below. Avalanches could have the consistency of wet concrete and will likely include rocks and wood debris, so you wouldn't want to be on the highway if that happens.
The Mt. St. Helens’ Spirit Lake Memorial Highway (SR 504) to the Johnston Ridge Observatory is scheduled to open at 7 a.m. Friday. At this time we are actively monitoring SR 504 but there are no planned closures for avalanche control.
Historic snowfall, combined with these warming temperatures also brings the possibility of flooding. Rivers most at risk of spring flooding in eastern Washington include the Naches, Yakima, Methow, Stehekin and Spokane. WSDOT crews are monitoring state highways near these rivers and an area adjacent to SR 970 east of Cle Elum on the Teanaway River.
As threat of rain remains low over the weekend, weather experts anticipate a low risk of flooding in western Washington
Know before you go:
• WSDOT offers several ways to get up-to-date traffic and construction information from our Web site at www.wsdot.wa.gov before you leave your home or office
• At www.wsdot.wa.gov/traffic/passes drivers can look at mountain pass conditions throughout the state
• At www.wsdot.wa.gov/traffic/trafficalerts the color-coded map shows statewide traffic conditions, including construction delays and highway incidents
• WSDOT offers weather information and road temperatures at www.wsdot.wa.gov/traffic/weather
• 511 - This driver information phone line provides real-time traffic, incident and closure information. Have a passenger call 511 for current traffic and weather information. TTY users can call 1-800-833-6388. Out of state callers can use 1-800-695-ROAD (7623).
• Drivers with Web service on their cellular phones and PDAs can access the Seattle area traffic flow map, ferry schedules, mountain pass reports at www.wsdot.wa.gov/small
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