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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 at us t0 increase the chance of precipitation. Another frontal system will move in Monday increasing the rain chances again.
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Advisories: NONE AT THIS TIME.
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Forecast for the Southern and lower Mid Willamette Valley including Eugene-Springfield and Albany-Corvallis: Cloudy with patchy AM fog and freezing fog, a good (50%) chance of rain this afternoon (under 0.10 in. of rain possible), rain this evening, a good (50%) chance of rain tonight (0.10 in. of rain possible), a (40%) chance of rain Sunday (under 0.10 in. of rain possible), rain Sunday night (0.15 in. of rain possible) and Monday, then mostly cloudy with rain Monday night highs 42-50 lows 35-42. Mostly cloudy with rain Tuesday though Wednesday, rain or snow showers likely (60%) at night, mostly cloudy with a good (50%) chance of rain and snow showers Thursday through Friday highs 50-43 lows 40-32. (seasonal averages high 46 low 34)
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Forecast for the Umpqua Basin including Roseburg: Mostly cloudy with patchy fog this AM, a (30%) chance of rain this afternoon (under 0.10 in. of rain possible), evening rain, rain likely (60%) tonight (0.10 in. of rain possible, snow level 3,500 ft. falling to 2,500 ft. late), a (40%) chance of AM rain and snow, rain and snow likely (60%) Sunday afternoon (under 0.10 in. of rain possible, snow level 2,500 ft.), cloudy with showers likely (60%) in the evening, showers late Sunday night (0.10 in. of rain possible), rain likely (70%) Monday, then cloudy with a (40%) chance of rain Monday night highs 49-40 lows 38-43. Mostly cloudy with a good (50%) chance of rain Tuesday, rain likely (70%) at night, rain and snow Wednesday, rain and snow showers likely (70%) at night, mostly cloudy with a (40%) chance of rain and snow showers Thursday, then mostly cloudy with a good (50%) chance of rain or snow showers Thursday night and Friday highs 52-40 lows near 42-32. (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 a slight (20%) chance of AM rain, coastal rain this afternoon with a good (50%) chance of inland rain this afternoon (0.10 in. of rain possible), rain this evening, a slight (20%) of rain late tonight (0.10 in. of rain possible), mostly cloudy with a good (50%) chance of AM coastal rain, rain likely (70%) Sunday afternoon (under 0.10 in. of rain possible), cloudy showers Sunday night ( 0.15 in. of rain possible), rain likely (70%) Monday, then mostly cloudy with a good (50%) chance of rain and breezy Monday night highs 54-48 lows 41-44. Mostly cloudy with a good (50%) chance of rain Tuesday, rain Tuesday night and Wednesday, rain and snow showers likely (70%) and colder Wednesday night, then mostly cloudy with a good (50%) chance of rain and snow showers Thursday through Friday highs 47-45 warming to 47 Friday lows 34-37. (seasonal averages high 51 low 40)
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Forecast for the Cascades of Lane County: Cloudy with a good (50%) chance of rain and snow this afternoon (under 0.10 in. of rain possible), rain or snow this evening, rain and snow likely (60%) tonight (0.10 in. of rain possible, 1 in. of snow possible), cloudy with a good (50%) chance of rain or snow Sunday AM, a slight (20%) of snow in the afternoon, mostly cloudy with rain or snow Sunday night and Monday, then rain Monday night snow level 4,500 ft. today, 3,500 ft. tonight, 2,500 ft. Sunday, 3,000 ft. Sunday night, rising to 5,500 ft. Monday, then 6,000 ft. Monday night highs 33-37 lows 23-30. Mostly cloudy with rain and snow likely (60%) Tuesday and Tuesday night, snow Wednesday, snow showers likely (60%) at night, a good (50%) of snow showers Thursday and Thursday night, then mostly cloudy with a (40%) chance of snow showers Friday snow level 5,500 ft. Monday, 6,000 ft. Monday night and Tuesday, 5,500 ft. Tuesday night, 2,500 ft. Wednesday, at the surface Wednesday night through Friday highs 35-24 warming to 32 Friday lows 26-17.
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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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