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No winner this week. Here is my weekly weather quiz question for the last time. What is ANOMALOUS PROPAGATION or (AP) for short? (And no, it’s not a rare disease) This is the correct answer. “Anomalous Propagation” occurs when non-standard atmospheric temperature or moisture gradients will cause all or part of the radar beam to propagate along a non-normal path. When non-standard index-of-refraction distributions prevail, “abnormal” or “anomalous” propagation occurs. When abnormal downward bending occurs, it is called “superrefraction.” If the beam is refracted downward sufficiently, it will illuminate the ground and return signals to the radar from distances further than is normally associated with ground targets. The term “subrefraction” is applied when there is abnormal upward bending of the radar beam. To simplify that definition, “AP’” is also nicknamed “radar junk” which would be radar images that are not real precipitation. I’ll have another weekly weather quiz question for you starting Monday. Pease 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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A high pressure ridge (shaded “arch” shape) dried us out and cooled us down, but now it is getting squeezed out by an upper level low pressure trough (shaded “U” shape) that is pushing a frontal system through Oregon t0 increase the chance of precipitation. Another frontal system will move in by mid week to continue the rain chances.
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Advisories: A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 9 AM SUNDAY FOR THE WESTERN COLUMBIA RIVER GORGE AND THE UPPER HOOD RIVER VALLEY.
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Forecast for the Southern and lower Mid Willamette Valley including Eugene-Springfield and Albany-Corvallis: Cloudy with rain this evening, a good (50%) chance of rain tonight (under 0.10 in. of rain possible), a good (50%) chance of rain Sunday (under 0.10 in. of rain possible), rain Sunday night (0.25 in. of rain possible), rain Monday (0.55 in. of rain possible) and Monday night (0.15 in. of rain possible), rain likely (60%) Tuesday, then cloudy with a good (50%) chance of rain Tuesday night lows 35-42 highs 45-52. Mostly cloudy with rain Wednesday, showers Wednesday night (snow level 1,000 ft), a good (50%) chance of rain and snow showers Thursday (snow level 1,000 ft.), a (40%) chance of rain and snow showers at night (snow level 1,000 ft.), a good (50%) chance of rain and snow showers Friday (snow level 1,000 ft.), then mostly cloudy with a (50%) chance of rain and snow showers Friday night and Saturday (snow level 1,000 ft.) highs near 45 lows 32-35. (seasonal averages high 46 low 34)
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Forecast for the Umpqua Basin including Roseburg: Mostly cloudy with rain this evening, rain likely (60%) tonight (0.10 in. of rain possible, snow level 3,500 ft.), partly cloudy with patchy AM fog and a slight (20%) chance of rain, mostly cloudy with a (30%) chance of showers Sunday afternoon (under 0.10 in. of rain possible, snow level 2,500 ft.), evening rain likely (70%), rain late Sunday night (0.10 in. of rain possible) and Monday (0.15 in of rain possible), evening showers, showers likely (60%) Monday night (0.10 in. of rain possible), mostly cloudy with showers likely (60%) Tuesday AM, a good (50%) chance of rain in the afternoon, then a slight (20%) chance of rain late Tuesday night lows 37-42 cooling to near 40 Tuesday night highs 46-50. Mostly cloudy with rain Wednesday AM, rain and snow in the afternoon, rain and snow showers and colder Wednesday night, mostly cloudy with a (40%) chance of rain and snow showers Thursday, a good (50%) chance of rain or snow showers Thursday night and Friday, then mostly cloudy with a (30%) chance of rain and snow showers Friday night and Saturday highs 44-36 warming to 42 Saturday lows near 32-30 warming to 34 Friday night. (seasonal averages high 49 low 36)
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Forecast for the South Oregon Coast including Coos Bay and North Bend: Cloudy with rain this evening, a slight (20%) of rain late tonight (0.10 in. of rain possible), mostly cloudy with patchy fog and a slight (20%) chance of AM coastal rain then a good (50%) chance of rain Sunday afternoon while partly cloudy in the AM inland and mostly cloudy with a good (50%) chance of afternoon showers (under 0.10 in. of rain possible), rain Sunday night (0.25 in. of rain possible) and Monday (0.40 in. of rain possible), evening showers, showers likely (60%) Monday night (0.25 in. of rain possible), mostly cloudy with AM showers likely (60%), a good (50%) chance of showers Tuesday afternoon, then mostly cloudy and breezy with a (30%) chance of rain Tuesday night lows 40-44 highs 48-50. Mostly cloudy with rain Wednesday, rain and snow showers and colder Wednesday night, a good (50%) chance of rain and snow showers Thursday and Thursday night, rain and snow showers likely (70%) Friday, mostly cloudy with a (40%) chance of showers Friday night and Saturday highs 47-42 warming to 47 Saturday lows 34-32 warming to 37 Friday night. (seasonal averages high 51 low 40)
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Forecast for the Cascades of Lane County: Mostly cloudy with rain and snow this evening, rain and snow likely (60%) tonight (0.10 in. of rain possible, 1 in. of snow possible), a good (50%) chance of rain and snow Sunday (under 0.10 in. of rain possible), mostly cloudy with rain and snow Sunday night ( 0.25 in. of rain possible, 1-4 in. of snow possible), rain Monday (0.10 in. of rain possible) and Monday night (0.10 in. of rain possible), rain Tuesday, then cloudy with a good (50%) chance of rain Tuesday night snow level 3,500 ft. tonight, 3,000 ft. Sunday and Sunday night, 6,000 ft. Monday, 6,500 ft. Monday night, then 6,000 ft. Tuesday and Tuesday night lows 23-30 cooling to 26 Tuesday night highs near 36. Mostly cloudy with rain and snow Wednesday, snow showers at night, a good (50%) of snow showers Thursday, a (40%) chance of snow showers Thursday night, mostly cloudy with a good (50%) chance of snow showers Friday and Friday night, then mostly cloudy with a (40%) chance of snow showers Saturday snow level 4,500 ft. Wednesday, then at the surface Wednesday night through Saturday highs 32-24 warming to 32 Friday and cooling to 27 Saturday lows 18-22.
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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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