________________
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.
________________
An upper level trough of low pressure (shaded “U” shape) is sliding eastward through the Pacific Northwest. A frontal system has moved through Oregon increasing the chance of precipitation. The next system can be seen off shore with its warm front moving ahead. Yet another frontal system will move in by mid week to continue the rain chances.
________________
Advisories: A WINTER STORM WATCH IS IN EFFECT FROM THIS EVENING THROUGH MONDAY MORNING EAST OF CASCADE LOCKS FOR THE WESTERN COLUMBIA RIVER GORGE AND THE UPPER HOOD RIVER VALLEY.
________________
Forecast for the Southern and lower Mid Willamette Valley including Eugene-Springfield and Albany-Corvallis: Mostly cloudy with a slight (20%) chance of light rain or drizzle this AM, a slight (20%) chance of rain this afternoon (under 0.10 in. of rain possible), rain tonight (0.50 in. of rain possible), rain Monday (0.50 in. of rain possible) and Monday night (0.15 in. of rain possible), cloudy with a good (50%) chance of rain Tuesday, a slight (20%) chance of rain in the evening, then cloudy with a good (50%) chance of rain Tuesday night highs 45-52 lows 37-42. Mostly cloudy with rain Wednesday, evening showers, a (40%) chance of rain and snow showers late Wednesday night, a good (50%) chance of rain and snow showers Thursday, a (30%) chance of rain and snow showers at night, a mix of clouds and sun with a good (50%) chance of rain and snow showers Friday, mostly cloudy with a slight (20%) chance of rain and snow Friday night, then a (40%) chance of rain and snow showers Saturday (snow level 1,000 ft.) highs 47-40 warming to 45 Saturday lows 32-26 warming to 35 Friday night. (seasonal averages high 46 low 34)
_______________
Forecast for the Umpqua Basin including Roseburg: Mostly cloudy with patchy AM fog and a slight (20%) chance of rain, mostly cloudy with a slight (20%) chance of showers this afternoon (under 0.10 in. of rain possible), rain tonight (0.10 in. of rain possible) and Monday (0.15 in of rain possible), evening showers, showers likely (60%) late Monday night (0.10 in. of rain possible), cloudy and becoming partly cloudy Tuesday with a (20%) chance of showers, then mostly cloudy with rain likely (60%) Tuesday night highs 46-54 lows 42-45 cooling to near 40 Tuesday night. 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. (seasonal averages high 49 low 36)
_________________
Forecast for the South Oregon Coast including Coos Bay and North Bend: Mostly cloudy with patchy fog this AM, a (30%) chance of showers this afternoon (under 0.10 in. of rain possible), rain tonight (0.25 in. of rain possible) and Monday (0.40 in. of rain possible), showers Monday night (0.25 in. of rain possible), cloudy with a (30%) chance of showers Tuesday, then mostly cloudy and breezy with rain Tuesday night highs 50-55 lows 44-50 cooling to 43 Tuesday night. Mostly cloudy with rain and breezy 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 (60%) Friday, mostly cloudy with a (40%) chance of showers Friday night, mostly cloudy with a (40%) chance AM rain and snow showers, then a (40%) chance of showers Saturday highs 47-42 warming to 47 Saturday lows near 34. (seasonal averages high 51 low 40)
_______________
Forecast for the Cascades of Lane County: Mostly cloudy with a slight (20%) chance of rain and snow this AM, a mix of clouds and sun this afternoon (under 0.10 in. of rain possible), a (30%) chance of rain and snow this evening, mostly cloudy with snow, freezing rain, and sleet tonight (0.50 in. of rain possible, 2-5 in. of snow possible), rain, freezing rain, and sleet and snow Monday AM, rain and snow in the afternoon (0.50 in. of rain possible, 2-5 in. of snow possible), rain Monday night (0.25 in. of rain possible), mostly cloudy with a good (50%) chance of rain Tuesday and Tuesday night snow level 3,000 ft. today and tonight, 5,500 ft. Monday, 6,500 ft. Monday night, then 6,000 ft. Tuesday and Tuesday night highs 35-39 lows 29-32 cooling to 26 Tuesday night. Mostly cloudy with rain and snow Wednesday, snow showers at night, a good (50%) of snow showers Thursday, a (30%) chance of snow showers Thursday night, mostly cloudy with a good (50%) chance of snow showers Friday, a (30%) chance of snow showers Friday night, then a mix of clouds and sun with a (40%) chance of snow showers Saturday snow level 5,000 ft. falling to 3,500 ft. Wednesday, then at the surface Wednesday night through Saturday highs 32-24 warming to 29 Saturday lows 22-14 warming to 22 Friday night.
________________
**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.
________________
Get your local Eugene-Springfield news on-line at Eugene Daily News.com.
________________