Showers and thunderstorms will be likely this week for most of the area. The best chance for thunderstorms west of the Cascades will be on Tuesday after which the threat will shift east to the Cascades and East Side.
Two storm systems will arrive back to back and bring periods of heavy rain to southern Oregon and northern California over the next several days. Snow levels will quickly rise to about 8000 feet early on Thursday and will linger there through Saturday before falling to around 5000 feet. This heavy rain will create the possibility for land slides and debris flows, rapid river rises and urban and small stream flooding.
A change in the weather pattern will move into the region Thursday. A front will bring rain into the area Thursday. Showers will diminish a little Friday before a round of rain, heavy at times, moves in Friday night. Snow levels will lower to the Cascade passes and to the valley floors east of the Cascades late Saturday into Sunday.
Around round of snow is expected today into tonight. Dashed lines indicate precipitation arrival times (could be rain at lower west side elevations). Snow will create hazardous travel with slippery roads, snow–covered at times, especially after sunset and periods of poor visibility.
Moderate to heavy snow will impact southern Oregon and northern California tonight into Friday. Snow will be wet and heavy and could cause tree limbs/branches to break. Power outages are possible. Heaviest snow will fall in the mountains above 2000 feet, and could fall in the valleys on Friday night. Be prepared for snow-covered and slippery roads and reduced visibility. Roads affected will be I-5, US Highway 97, US Highway 395, Highway 3, Highway 62, Highway 140, and more.
High mountains are going to get feet of snow. Snow levels will lower sharply behind a cold front, starting Thursday morning, and mountain passes may see a period of moderate to heavy snow Thursday morning.
WIND ADVISORY REMAINS IN EFFECT FROM 11PM THIS EVENING TO 5PM PDT TUESDAY
A strong low pressure system will bring moderate to strong winds to the forecast area through Tuesday. Difficult travel is expected in some areas, especially for high-profile vehicles.
Winter Storm Warning / Winter Weather Advisory for Klamath Basin.
Snow and blowing snow. Additional snow accumulations of 4 to 6 inches, with localized amounts up to 12 inches are expected. Small hail and heavier snow are possible with thunderstorms this afternoon in Klamath and lake counties. Winds of 25 to 30 mph with gusts up to 45 mph are expected this afternoon and evening for much of the Klamath Basin.
Snow levels can fluctuate dramatically depending on many factors, including precipitation intensity. But, the bottom line is to be prepared for wintry travel mainly above 4000 feet today with snow possible all the way to west side valley floors again late Thursday into Friday.
The snow level drops to 2500 feet tonight with a period of moderate to heavy snow likely, especially along Interstate 5 near Mount Shasta and also in the mountains.
The next series of systems will bring some rain and snow to the west coast. The first system will arrive on Wednesday will bring 4000 foot snow levels with it, and those snow levels will begin to decrease on Thursday before falling to the valley floors by early Friday morning. The heaviest snowfall will be in the Cascades and the Marble mountains with a heavy dose of snow forecast for Mt. Shasta.
The active winter pattern is set to continue again this morning through tonight as the next system approaches the Pacific Northwest.
This means heavy snow with significant accumulations are likely over the Cascades, especially from around highway 140 north. Moderate to heavy snow is also expected over the Siskiyous, including Siskiyou Summit and highway 97 north of Chiloquin, but storm totals will be less than in the Cascades. Snow is expected to be heaviest from late this morning through this evening, then gradually tapering off tonight.
Another frontal system will move in from the northwest tonight through Saturday as the active wintry weather pattern continues.
Moderate to heavy snowfall is expected in the Oregon Cascades, with lighter amounts possible down to between 1,000 and 2,000 foot elevations. Snow levels are expected to range between 1,000 and 2,000 feet during this weather system with the bulk of the 1+ inch accumulations above 2000 feet.
The majority of the snowfall will occur during the day on Saturday. Roadways from Highway 140 near Lake of the Woods northward will see the greatest accumulations, but other roadways south of there, including portions of I-5, could see some light snowfall, as well.
Be prepared for periods of reduced visibility and slippery and snow covered roads. Be prepared for wintry travel conditions and be sure to check road conditions before venturing out.
Monitor the forecast closely for updates. It’s a good idea to have alternate travel plans if you want to avoid driving in wintry conditions.
Yet another low pressure system will move in from the north tonight into Thursday bringing snow to most of the area. Snow will arrive from northwest to southeast late tonight/early Thursday morning.
See the timelines in the graphic. Once again, the highest accumulations are likely to occur in the mountains, but also the passes along Interstate 5.
A burst of snow during the morning commute could also cause a period of reduced visibility and slippery, snow covered roads over the west side valleys. So, be prepared for wintry travel conditions and be sure to check road conditions before venturing out.
With the potential for poor weather and hazardous road conditions in the next several days the Oregon State Police (OSP) would like to remind motorists of winter travel safety tips.
An arctic front will make it’s way through the area late tonight, bringing widespread precipitation with it. A very cold air mass will follow and showers will also continue through Sunday into Monday afternoon.
Snow levels will fall to west side valley floors [Rogue Valley] late tonight, remaining there through Monday. All area passes will be affected by accumulating snow and even the beaches will likely see some snow accumulations Sunday into Monday.
Heavy snow will impact the mountains tonight through Thursday. Snow levels will gradually rise from 3000 feet this evening to 7000 feet Saturday afternoon as a warm front moves through.
WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST THIS EVENING
Snow occurring. Plan on difficult travel conditions,including during the morning commute. Additional snow accumulations of 3 to 9 inches, with localized amounts up to 12 inches, are expected today.
Another fairly strong frontal system in the recent parade will arrive Tuesday with increasing southerly winds for many areas. Significant rainfall is expected at lower elevations Tuesday through Wednesday, with significant snowfall expected for elevations above 3500 to 4000 feet Wednesday. While model guidance continues to waiver on day to day precipitation amounts and the strength of individual frontal systems, there is increasing confidence that unsettled weather with more frontal systems will generally continue into early next week. Stay tuned for more details and updates through the next week!
Winter storm to bring snow to Cascades and Siskiyous Sunday. A winter storm will move into the region Sunday. The snow levels will remain at 3000 to 3500 feet for most of the storm, bringing the possibility of heavy snow to portions of Siskiyou county. The Cascades and portions of the east side are expected to see lesser, but still significant, accumulations with the storm.
Mountain Snow Expected Thursday through Friday
A wet Pacific storm will bring snow to the mountains Thursday. Snow levels initially will be in the 6000 to 7000 foot range but are expected to lower to 4500 feet by early Thursday afternoon. By Thursday night snow levels are expected to lower to around 3000 feet. This will impact travel over the passes in the Cascade and Siskiyou Mountains Thursday night and Friday. There will be a break on Saturday but another storm is expected to impact the mountains Sunday into early next week.
High pressure over the area will result in light winds and inversion conditions tonight through Tuesday. This will cause moisture and particulates to remain generally trapped in the valleys. This could result in diminished air quality that could affect public health, especially for people with respiratory sensitivities. AIR STAGNATION ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO NOON PST TUESDAY
Southwest winds will increase east of the Cascades Friday afternoon ahead of a strong cold front. The strongest winds are likely to occur late Friday afternoon and are expected to decrease below warning levels by late Friday evening.
Modoc County, Northern and Eastern Klamath County, Western Lake County, Central and Eastern Lake County, Including the city of Valley Falls
WINTER STORM WARNING - Above 2500' in effect from 1:00 PM Tuesday to 7:00 AM Wednesday.
WINTER WEATHER ADVISORY - Above 2000' in effect from 1:00 PM Tuesday to 7:00 AM Wednesday.
Low elevation snow to affect all mountain passes above 2000 feet Tuesday and Wednesday
Snow is expected to impact all mountain passes and potentially some West Side valleys late Tuesday into Wednesday.
If you plan on traveling during this time, be sure to carry an emergency travel kit with you. This travel kit should include: blankets, food, water, fully charged cell phone, chains, and any necessary medications. Be sure to check the latest road conditions before venturing out and stay up to date with the most recent forecasts.
High pressure to bring more stagnation this weekend... AIR STAGNATION ADVISORY REMAINS IN EFFECT FROM 7 PM THIS EVENING TO 8 AM PST TUESDAY
Air stagnation advisory remains in effect from 4:00 AM Tuesday (12/5/17) to 10:00 AM Saturday (12/9/17).
An air stagnation advisory indicates that due to limited movement of an airmass across the advisory area, pollution will increase.
At the Oregon Department of Transportation, we prepare for winter weather year round.
Even before the last of the snow melts our crews are reviewing lessons learned, adjusting plans for the next season, making repairs to heavy equipment and working on improvements to TripCheck.com, our 24/7 road condition and travel information website.
According to the US National Weather Service in Medford, Ore - Gusty south winds are expected to occur across portions of southern Oregon and northern California tonight into Monday Night. These winds will become strong along the coast, north-south oriented valleys west of the Cascades, the Shasta Valley, and the East Side. Travel on Interstate 5 as well as highways, 31, 39, 97, 101, 140, and 395 could become difficult