The National Weather Service has issued a Winter Storm Warning, Winter Storm Watch, and Winter Weather Advisory for Oregon. They are in effect t=Tonight through Friday Evening. Heavy snowfall is forecasted to impact the area, especially the mountains and possibly the lowlands.
6-18″ of Snow Tonight – Friday Night.
Snow levels are forecasted to fluctuate between 1,000ft and 1,500ft.Â
Additional Storm Info:
Oregon:Â 6-18″ of Snow Tonight – Friday Night
* Total snow accumulations of 6 to 12 inches, with localized amounts up to 18 inches, are  possible. - NOAA Medford, OR
OR Winter Storm Watch:
URGENT - WINTER WEATHER MESSAGE National Weather Service Medford OR 417 AM PDT Thu Mar 22 2018 ...Heavy mountain snow and possible low land snow Tonight into Friday night... .A strong cold front will move through southern Oregon and northern California today. As cold air pours in behind the front tonight, snow levels will drop rapidly to around 1500 feet. Snow levels will then fluctuate between 1500 and 2500 feet, highest during Friday afternoon. At the same time, a rich plume of Pacific moisture will take aim at the area, and the result will be very heavy snow in the mountains. Particularly hard hit will be the mountains of Curry, Josephine, and western Siskiyou counties where several feet of snow are possible. Heavy snow is also expected over the Cascades, Mt. Shasta area, and portions of the east side, although confidence in snow amounts is lower for these areas. Snow may also impact lower elevations at times, especially at night and especially the more snow-prone areas like the I-5 Passes north of Grants Pass and the Illinois Valley. South Central Oregon Cascades- Including the cities of Crater Lake, Crescent Lake, Diamond Lake, and Union Creek ...WINTER STORM WATCH REMAINS IN EFFECT FROM LATE TONIGHT THROUGH FRIDAY EVENING... * WHAT...Heavy snow possible. Total snow accumulations of 6 to  12 inches, with localized amounts up to 18 inches, are  possible. * WHERE...South Central Oregon Cascades including Crater Lake  and Diamond Lake. * WHEN...From late tonight through Friday evening. * ADDITIONAL DETAILS...Travel could be very difficult to  impossible, including during the evening commute on Friday.  Significant reductions in visibility are possible. In addition,   southwest winds of 20 to 30 mph will create areas of blowing  snow, especially over peaks and exposed areas.