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No winner this week. Here is my weekly weather quiz question for the last time. What is the average ratio of melted liquid to actual snowfall? In other words how much melted snow (liquid amount) will equal a specific amount of snow? Here is the correct answer. “Meteorologists developed a rule of thumb years ago that said ten inches (25 cm) of snow would melt down to 1 inch (2.5 cm) of water (or be the equivalent amount of rain if it fell as liquid), and that proportion was often used to determine the amount of equivalent precipitation from a snowfall. But that 10:1 ratio, we now know, is far from exact, and generally wrong across the breadth of conditions under which snow falls, even within an individual storm. When snow falls at air temperatures around freezing (32 oF / 0 oC), the ratio of snow to water equivalent comes close to the 10:1 ratio. However the full range is from around 100:1 to 3:1, depending on other weather factors such as air temperature, snow crystal structure and wind speed. In the United States, the ratio typically falls in the 8:1-20:1 range: the standard value used by the US National Weather Service for converting snowfall into liquid water equivalent when observers cannot melt down the gage-caught snow is 13:1.” I’ll have a new weekly weather quiz question for you starting Monday. 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.
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Another upper level trough of low pressure has moved down from the Gulf of Alaska and will slowly push eastward over us. A frontal system slowly moved through Oregon continuing the showers. Part of that storm moved through Northern California spinning precipitation into the area mainly between Roseburg and Medford. A new frontal system will be approaching the Pacific Northwest Christmas morning (position shown is Wednesday). Sorry, no white Christmas for the valleys only the mountains.
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Advisories: A WINTER STORM WARNING IS IN EFFECT FROM MIDNIGHT TONIGHT THROUGH 10 PM SUNDAY ABOVE 2,000 FT. FOR CENTRAL DOUGLAS COUNTY, THE EASTERN DOUGLAS COUNTY FOOTHILLS, EASTERN CURRY COUNTY COUNTY AND JOSEPHINE COUNTY, AND JACKSON COUNTY. A WINTER STORM WARNING IS IN EFFECT FROM MIDNIGHT TONIGHT UNTIL 10 PM SUNDAY FOR THE SOUTH CENTRAL OREGON CASCADES, THE SOUTH OREGON CASCADES, AND THE SISKIYOUS MOUNTAINS. A WINTER STORM WARNING IS IN EFFECT FROM 4 AM UNTIL 10 PM SUNDAY FOR THE KLAMATH BASIN, NORTHERN AND EASTERN KLAMATH COUNTY, WESTERN, CENTRAL , AND EASTERN LAKE COUNTY. A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL MIDNIGHT TONIGHT ABOVE 2,000 FT. FOR CENTRAL DOUGLAS COUNTY, EASTERN CURRY COUNTY AND JOSEPHINE COUNTY, THE EASTERN DOUGLAS COUNTY FOOTHILLS, AND JACKSON COUNTY. A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL MIDNIGHT TONIGHT FOR THE SOUTH OREGON CASCADES AND THE SISKIYOUS MOUNTAINS.
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Forecast for the Southern and lower Mid Willamette Valley including Eugene-Springfield and Albany-Corvallis: Mostly cloudy with showers tonight (0.10 in. of rain possible), showers Sunday (0.25 in. of rain possible), showers Sunday evening, a good (50%) chance of showers late at night (0.15 in. of rain possible), a mix of clouds and sun with a slight (20%) chance of showers Monday AM, then mostly cloudy with rain likely (60%) Monday night (0.15 in. of rain possible), rain Tuesday (Christmas Day) and Tuesday night lows 36-33 warming to 38 Tuesday night highs near 44. Mostly cloudy with showers likely (70%) Wednesday and Wednesday night, mostly cloudy with a good (50%) chance of showers Thursday and Thursday night, a (30%) chance of showers Friday, then mostly cloudy with a slight (20%) chance of showers Friday night and Saturday highs 44-42 lows 36-34. (seasonal averages high 45 low 33)
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Forecast for the Umpqua Basin including Roseburg: Mostly cloudy with evening rain and snow showers, rain and snow late tonight (0.15 in. of rain possible, 2 in. of snow possible, snow level 2,500 ft. falling to 2,000 ft), rain and snow Sunday (0.35 in. of rain possible, snow level 1,500 ft. rising to 2,000 ft. in the afternoon), rain and snow showers likely (70%) Sunday night (under 0.10 in. of rain possible), a slight (20%) chance of rain and snow showers Monday, then rain and snow likely (60%) Monday night (under 0.10 in. of rain possible) lows 37-34 warming to 38 Tuesday night highs near 42-46. Mostly cloudy with a good (50%) chance of rain and snow showers Monday, a slight (20%) chance of rain and snow Monday night, AM rain and snow likely (60%), AM rain and snow, rain Tuesday afternoon (Christmas Day), rain Tuesday night, rain and snow showers likely (60%) Wednesday and Wednesday night, a (40%) chance of rain and snow showers Thursday and Thursday night, then mostly cloudy with a slight (20%) chance of rain and snow showers Friday highs near 43 lows 35-30. (seasonal averages high 47 low 36)
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Forecast for the South Oregon Coast including Coos Bay and North Bend: Mostly cloudy with showers this evening, rain late tonight (0.35 in. of rain possible, snow level 2,000 ft. late at night), rain Sunday (0.50 in. of rain possible, AM snow level 2,000 ft.), evening showers likely (70%), a good (50%) chance of showers late Sunday night (under 0.10 in. of rain possible, snow level 2,000 ft. late), a slight (20%) chance of showers Monday AM, mostly cloudy in the afternoon, coastal rain late Monday night with rain likely (70%) inland Monday night (0.20 in. of rain Monday night), mostly cloudy with rain Tuesday (Christmas Day) and Tuesday night lows 42-36 warming to near 40 Tuesday night highs 46-50. Mostly cloudy showers likely (70%) Wednesday and Wednesday night, a good (50%) chance of showers Thursday and Thursday night, then mostly cloudy with a slight (20%) chance of showers Friday through Saturday highs near 48 lows 38-34. (seasonal averages high 51 low 40)
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Forecast for the Cascades of Lane County: Mostly cloudy with snow showers this evening, snow showers tonight (1-2 in. of snow possible), snow showers Sunday (3-6 in. of snow possible), snow showers Sunday night (1-3 in. of snow possible), a good (50%) chance of snow showers Monday AM, a slight (20%) chance of snow showers in the afternoon, a good (50%) chance of snow late Monday night, mostly cloudy with rain and snow Tuesday (Christmas Day) and Tuesday night snow level at the surface tonight through Monday night, 2,500 ft. Tuesday, then 4,000 ft. Tuesday night lows 26-23 warming to 28 Monday night cooling to 25 Tuesday night highs 33-30. Mostly cloudy with rain and snow showers likely (60%) Wednesday, snow showers likely (60%) Wednesday night, mostly cloudy with a good (50%) chance snow showers Thursday and Thursday night, a (30%) chance of snow showers Friday, a slight (20%) chance of snow showers Friday night, then just mostly cloudy Saturday snow level 3,000 ft. Wednesday, at the surface Wednesday night and Thursday, 2,500 ft. Thursday night, at the surface Friday, 2,500 ft. Friday night, then at the surface Saturday highs near 30 lows 22-25.
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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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Get your local Eugene-Springfield news on-line at Eugene Daily News.com.
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