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Here is my weekly weather quiz question. What is the “Pacific Decadal Oscillation?” Please remember to post your answer as a comment by clicking on “no comments /comments” in the upper right hand portion of this page under the caption, then add your comment. The first person to post the correct answer will win a week of free personalized weather forecasts tailored to your needs. The answer has to be a comment to win. An email answer will not count. Good Luck!
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Another upper level trough of low pressure (shaded “U” shape) has moved in along the coast as cold high pressure (shaded “Arch shape”) moves away from the Pacific Northwest. The next frontal system can be seen moving through with its warm front past first and the cold front followed behind it today. Snow levels will fall to about 1,000 ft. Thursday night, but I don’t expect the snow to stick enough to pile up any significant accumulation on the valley floor. We’ll have to keep an eye on that situation. A frontal system will approach Oregon over the weekend returning the threat of falling snow levels.
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Advisories: A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 10 AM THURSDAY FOR THE COAST RANGE OF NORTHWEST OREGON. A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL MIDNIGHT TONIGHT FOR THE NORTHERN OREGON CASCADES AND THE CASCADES IN LANE COUNTY. A FREEZE WARNING IS IN EFFECT FROM 1 AM UNTIL 8 AM THURSDAY FOR SOUTH CENTRAL AND SOUTH OREGON COAST. A FROST ADVISORY IS IN EFFECT FROM 1 AM UNTIL 8 AM THURSDAY FOR SOUTH CENTRAL AND SOUTH OREGON COAST. A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 7 AM THURSDAY ABOVE 1,000 FT. FOR THE SOUTH CENTRAL AND SOUTH OREGON COAST. A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 10 AM THURSDAY ABOVE 1,000 FT. FOR CENTRAL DOUGLAS COUNTY, EASTERN CURRY COUNTY, AND JOSEPHINE COUNTY. A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 10 AM THURSDAY FOR JACKSON COUNTY, THE EASTERN DOUGLAS COUNTY FOOTHILLS, THE SOUTH CENTRAL OREGON CASCADES, THE SOUTH OREGON CASCADES, AND THE SISKIYOU MOUNTAINS.
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Forecast for the Southern and lower Mid Willamette Valley including Eugene-Springfield and Albany-Corvallis: Cloudy with evening showers likely (60%), rain and snow showers likely (60%) and colder late tonight (0.10 in. of rain possible, under 1 in. of snow possible), mostly cloudy with rain and snow showers likely (60%) Thursday AM, a good (50%) chance of rain and snow showers in the afternoon (under 0.01 in. of rain possible, under 1 in. of snow possible), a (40%) chance of rain and snow showers Thursday night (under 0.10 in. of rain possible), mostly cloudy with a good (50%) chance of rain and snow showers Friday AM, a slight (20%) chance of rain and snow showers in the afternoon, partly cloudy in the evening, mostly cloudy with a slight (20%) chance of rain and snow late Friday night (snow level 1,000 ft.), mostly cloudy with a slight (20%) chance of rain and snow Saturday AM, a good (50%) chance of rain and snow in the afternoon, cloudy with a good (50%) chance of showers Saturday night lows 32-25 highs 42-39. A mix of clouds and sun with a slight (20%) chance of showers Sunday, a slight (20%) chance of showers Sunday night, patchy AM fog and freezing fog Monday, mostly cloudy in the afternoon, partly cloudy Monday night, AM fog, a mix of clouds and sun Tuesday, partly cloudy at night, then AM fog and a mix of clouds and sun Wednesday highs 44-46 lows 30-35. (seasonal averages high 46 low 34)
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Forecast for the Umpqua Basin including Roseburg: Mostly cloudy with rain and snow showers tonight (0.20 in. of rain possible, 1 in. of snow possible lower elevations and 1-2 in. of snow possible above 1,500 ft., snow level 1,500 ft. falling to 400 ft. late at night), rain and snow showers likely (60%) Thursday (0.10 in. of rain possible, 1 in. of snow possible at lower elevations, 1-2 in. of snow possible above 1,500 ft., snow level 400 ft. rising to 900 ft. in the afternoon), rain and snow showers likely (70%) Thursday night (under 0.10 in. of rain possible, 1 in. of snow possible, snow level 1,000 ft.), rain and snow showers likely (60%) Friday AM, a good (50%) chance of rain and snow showers in the afternoon (under .10 in. of rain possible, snow level 900 ft. rising to 1,500 ft. in the afternoon), mostly cloudy with a slight (20%) chance of rain and snow showers Friday night (under 0.10 in. of rain possible), mostly cloudy with a slight (20%) chance of AM rain, a (30%) chance of rain and snow Saturday afternoon, rain and snow showers likely (60%) Saturday night lows 32-30 warming to 34 Saturday night highs 40-44. Mostly cloudy a (40%) chance of rain and snow showers Sunday, a slight (20%) chance of showers Sunday night, partly cloudy with patchy AM fog and freezing fog Monday AM, partly cloudy in the afternoon and Monday night, patchy AM fog, then just partly cloudy Tuesday afternoon highs 46-50 lows 32-38. (seasonal averages high 49 low 36)
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Forecast for the South Oregon Coast including Coos Bay and North Bend: Mostly cloudy with coastal showers and isolated thunderstorms with inland rain and snow showers tonight (0.15 in. of rain possible, 1 in. of snow possible, snow level 1,500 ft. falling to 1,000 ft. late at night), coastal showers likely (60%) with rain and snow showers likely (70%) inland Thursday afternoon (0.10 in. of rain possible, 1 in. of snow possible, snow level 1,000 ft.), coastal showers likely (60%) and rain and snow showers likely (70%) inland Thursday night (0.10 in. of rain possible, 1 in. of snow possible, snow level 1,500 ft. falling to 1,000 ft.), AM showers likely (60%), coastal showers likely (70%) Friday afternoon with inland rain and snow showers (0.10 in. of rain possible) likely (60%), then mostly cloudy with a (40%) chance of showers Friday night, mostly cloudy with a good (50%) chance of showers Saturday, then showers likely (60%) Saturday night lows 35-38 cooling to 32 Friday night warming to 36 Saturday night highs 44-47. Mostly cloudy with a (40%) chance of showers Sunday, a slight (20%) chance of showers Sunday night, patchy AM fog, mostly cloudy Monday afternoon, partly cloudy at night, mostly cloudy with patchy AM fog, mostly sunny Tuesday afternoon, partly cloudy at night, mostly cloudy with areas of patchy AM fog, then mostly sunny Wednesday afternoon highs 46-53 lows near 39. (seasonal averages high 51 low 40)
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Forecast for the Cascades of Lane County: Mostly cloudy with snow showers (1-3 in. of snow possible) and colder tonight, snow showers likely (70%) Thursday (1-4 in. of snow possible) cloudy with evening showers likely (60%), a (70%) chance of snow showers Thursday night (2 in. of snow possible), mostly cloudy with a good (50%) of snow showers Friday, partly cloudy with a slight (20%) chance of evening snow showers, mostly cloudy with a slight (20%) chance of snow late Friday night, a slight (20%) chance of snow Saturday, then mostly cloudy with a good (50%) chance of snow showers Saturday night snow level at the surface tonight through Saturday night lows 19-14 highs 27-23 warming to 28 Saturday. A mix of clouds and sun with a (30%) chance of snow showers Sunday, partly cloudy with a slight (20%) chance of snow showers Sunday night, just partly cloudy Monday and Monday night, then mostly sunny Tuesday and Wednesday with mostly clear skies Tuesday night snow level at the surface Sunday and Sunday night, free air freezing level at the surface Monday, 5,500 ft. Monday night, 7,000 ft. Tuesday, 9,000 ft. Tuesday night, then 10,000 ft. Wednesday highs 29-40 lows 17-24.
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**Because weather forecasting is a combination of science, intuition, and timing there can be no absolute guarantees that individual forecasts will be 100% accurate. Nature is in a constant state of flux and sudden unexpected weather events can happen.
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