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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 and a new frontal system is pushing through California and southern Oregon. There will be a break on Monday as the trough of low pressure passes east of us and and a weak ridge takes over. A new frontal system (position shown is Wednesday) and along with a new trough of low pressure will to bring more wet weather for Christmas. Sorry, no white Christmas for the valleys only the mountains and foothills.
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Advisories: A BLIZZARD WARNING IS IN EFFECT UNTIL 10 PM TONIGHT FOR NORTHERN AND EASTERN KLAMATH COUNTY, WESTERN, CENTRAL , AND EASTERN LAKE COUNTY. A WINTER STORM WATCH IS IN EFFECT FROM LATE MONDAY NIGHT THROUGH LATE TUESDAY NIGHT FOR THE WESTERN COLUMBIA RIVER GORGE, THE NORTH OREGON CASCADE FOOTHILLS, THE NORTH OREGON CASCADES, THE CASCADES IN LANE COUNTY, AND THE UPPER HOOD RIVER VALLEY. A WINTER STORM WARNING IS IN EFFECT THROUGH 10 PM TONIGHT ABOVE 2,500 FT. FOR CENTRAL DOUGLAS COUNTY, THE EASTERN DOUGLAS COUNTY FOOTHILLS, EASTERN CURRY COUNTY COUNTY, JOSEPHINE COUNTY, AND JACKSON COUNTY. A WINTER STORM WATCH IS IN EFFECT FROM LATE MONDAY NIGHT THROUGH LATE TUESDAY NIGHT FOR THE SOUTH CENTRAL OREGON CASCADES, THE SOUTH OREGON CASCADES, AND THE SISKIYOUS MOUNTAINS. A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 10 PM TONIGHT FOR SOUTH OREGON CASCADES AND THE SISKIYOU MOUNTAINS, AND THE KLAMATH BASIN.
A FLOOD WARNING CONTINUES FOR THE COQUILLE RIVER AT COQUILLE. MINOR FLOODING IS OCCURRING AS WAS EXPECTED. FOR MORE DETAILS GO TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE AT PORTLAND FLOOD WARNING PAGE.
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Forecast for the Southern and lower Mid Willamette Valley including Eugene-Springfield and Albany-Corvallis: Cloudy with showers this evening, a good (50%) chance of showers late tonight (0.10 in. of rain possible), a mix of clouds and sun with a slight (20%) chance of showers Monday AM, mostly cloudy with rain late Monday night (0.25 in. of rain possible), rain (0.50 in. of rain possible) Tuesday (Christmas Day) and Tuesday night (0.25 in. of rain possible), then mostly cloudy with showers Wednesday and showers likely (60%) Wednesday night lows 37-40 cooling to 35 Wednesday night highs near 45. A mix of clouds and sun with a (40%) chance of showers Thursday, mostly cloudy with a slight (20%) chance of showers Thursday night through Friday night, then a mix of clouds and sun Saturday and Sunday with mostly cloudy skies Saturday night highs near 43 lows near 34. (seasonal averages high 45 low 33)
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Forecast for the Umpqua Basin including Roseburg: Cloudy with rain and snow showers likely (60%) this evening, a good (50%) chance of rain and snow showers late tonight (under 0.10 in. of rain possible, 1 in. of snow possible, snow level 2,500 ft. falling to 2,000 ft. late), just mostly cloudy Monday, mostly cloudy with a good (50%) chance of rain and snow late Monday night (under 0.10 in. of rain possible, snow level 2,000 ft.), rain (0.30 in. of rain possible, AM snow level 3,500 ft.) Tuesday (Christmas Day), rain (0.20 in. of rain possible) Tuesday night, rain and snow showers Wednesday, then rain and snow showers likely (70%) Wednesday night lows 36-38 cooling to 34 Wednesday night highs near 42-46 cooling to 43 Wednesday. Mostly cloudy with a (40%) chance of rain and snow showers Thursday, a slight (20%) chance of rain and snow showers Thursday night and Friday, just mostly cloudy Friday night and Saturday, mostly cloudy with a slight (20%) chance of rain and snow showers Saturday night, then mostly cloudy with a slight (20%) chance of showers Sunday highs 43-46 lows near 32. (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 coastal showers likely (70%) tonight with showers this evening and a good (50%) chance of showers late tonight inland (0.10 in. of rain possible, snow level 2,000 ft. late), just mostly cloudy Monday, cloudy with a slight (20%) chance of evening rain, coastal rain late with rain likely (70%) late Monday night inland (0.10 in. of rain Monday night), mostly cloudy with rain (0.70 in. of rain possible) Tuesday (Christmas Day) and breezy (wind: S 15-25 mph), rain (0.45 in. of rain possible) Tuesday night, showers Wednesday, then mostly cloudy with showers likely (70%) Wednesday night lows 37-42 cooling to 38 Wednesday night highs 46-50 cooling to near 45 Wednesday night. Mostly cloudy with a (40%) chance of showers Thursday, then a slight (20%) chance of showers Thursday night through Sunday highs near 48 lows 37-34. (seasonal averages high 51 low 40)
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Forecast for the Cascades of Lane County: Mostly cloudy with snow showers tonight (1-4 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, mostly cloudy with rain and snow showers Wednesday, then rain and snow showers likely (60%) Wednesday night snow level 2,500 ft. tonight, at the surface Monday, free air freezing level at the surface in the evening, back to snow level at the surface Monday night, 2,500 ft. rising to 3,500 ft. Tuesday, 4,500 ft. Tuesday night, 3,000 ft. Wednesday, then 2,500 ft. Wednesday night lows 24-27 cooling to 22 Wednesday night highs 30-34 cooling to near 30 Wednesday night. Mostly cloudy with a good (50%) chance snow showers Thursday, a slight (20%) chance of snow showers Thursday night through Friday night, a mix of clouds and sun Saturday, mostly cloudy with a slight (20%) chance of snow showers Saturday night, then a mix of clouds and sun Sunday snow level at the surface Thursday through Friday night, free air freezing level at the surface Saturday, then back to snow level at the surface Saturday night and Sunday highs near 32 lows 20-25.
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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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