Here is my weekly weather quiz question  for the last time. What is “Attenuation?” Here is the correct answer. Attenuation refers to the reduction of the radar beam power due to the reflection or absorption of energy when it strikes a target. The greatest attenuation occurs when the radar beam goes through very heavy rain. I’ll have a new weather quiz question for you starting Monday. The first person to post the correct answer as a comment on this page will win a week of free personalized weather forecasts tailored to your needs.  Good luck.

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An Upper Level Low Pressure Trough (Shaded “U” shape with blue arrows) is moving out of the Gulf of Alaska to keep the rain chances with us. The graphics for days 3-7 show a frontal system pushing through the Pacific Northwest Monday night and Tuesday.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 4 in the Good category measuring Particulate Matter.

Oakridge: The Air Quality Index is 8 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 1 in the Good category measuring Particulate Matter.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

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Home Wood Heating Advisory:

Eugene-Springfield: GREEN – Burning is Allowed.

Oakridge: GREEN – Burning is Allowed.

*Note: Pellet stoves may be used anytime if they produce no visible emissions.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

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Advisories:

• A Permanent Health Advisory remains in effect for the South Umpqua River and Lawson Bar. Pools in the bedrock along the rivers edge are known to develop Blue-green Algae (cyanobacterial) blooms that can be harmful to pets and people if accidental ingestion occurs. Signs have been posted along several access areas along the river.

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Forecast for the Southern and lower Mid Willamette Valley including Eugene-Springfield and Albany-Corvallis:

• Mostly cloudy with showers and a slight (20%) chance of thunderstorms and small hail possible this evening, a good (50%) chance of showers late tonight (0.10 in. of rain possible, more in storms) and Sunday AM, showers (0.10 in. of rain possible) likely (70%) and a bit warmer Sunday afternoon (Mother’s Day), a (40%) chance of evening showers, a slight (20%) chance of showers late at night,
• Cloudy with a good (50%) chance of showers and a bit cooler Monday, rain Monday night,
• Mostly cloudy with showers and a bit warmer Tuesday, then a good (50%) chance of showers Tuesday night.
• lows 42-45 cooling back to 42 Tuesday night highs 58-56 warming back to 58 Tuesday.
• Mostly cloudy and a bit warmer with a (40%) chance of afternoon showers Wednesday, a slight (20%) chance of showers at night,
• A mix of clouds and sun and a bit warmer Thursday and Friday, partly cloudy both nights,
• Then mostly sunny and a bit warmer Saturday.
• highs 62-72 lows 37-44. (seasonal averages high 67 low 43)

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Eugene-Springfield Pollen Count:

Grass………. Moderate (19)

Trees………. Moderate (73)

Last Counted: 5/10/17

Data Courtesy of Oregon Allergy Associates.

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Forecast for Roseburg:

• Mostly cloudy with evening showers likely (70%), a (40%) chance of showers late tonight,
• Mostly cloudy with a (40%) chance of showers and a bit warmer Sunday (Mother’s Day), a slight (20%) chance of showers at night,
• Cloudy with a (40%) chance of showers Monday (AM snow level 3,500 ft.), rain Monday night,
• Mostly cloudy with AM showers, showers likely (70%) and a bit cooler Tuesday afternoon and evening, a good (50%) chance of showers late at night.
• lows 43-46 highs 62-55.
• Mostly cloudy with a (40%) chance of showers and a bit warmer Wednesday, a slight (20%) chance of showers in the evening, just partly cloudy late Wednesday night,
• Partly cloudy and a bit warmer Thursday and Thursday night,
• Then sunny and a bit warmer Friday and Saturday, mostly clear Friday night.
• highs 64-76 lows 43-46. (seasonal averages high 70 low 47)

 

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Forecast for The South Central Oregon Coast Including Coos Bay and North Bend:

• Mostly cloudy with evening showers likely (70%), a good (50%) chance of showers late tonight (under 0.10 in. of rain possible),
• Mostly cloudy with a (40%) chance of AM showers, partly cloudy and a bit warmer with a slight (20%) chance of showers Sunday afternoon (Mother’s Day), a slight (20%) chance of evening coastal showers, just mostly cloudy late Sunday night,
• Mostly cloudy with a good (50%) chance of showers and a bit cooler Monday, rain at night,
• Mostly cloudy with AM showers, showers likely (70%) and a bit cooler Tuesday afternoon and in the evening, then a good (50%) chance of showers Tuesday night.
• lows 45-48 highs 57-54.
• Mostly cloudy with  a (30%) chance of AM, partly cloudy with a slight (20%) chance of showers and a bit warmer Wednesday afternoon and in the evening, just mostly cloudy Wednesday night and Thursday AM, then partly cloudy and a bit warmer Thursday afternoon through Friday night,
• Then sunny and a bit cooler Saturday.
• highs 58-63 cooling to 59 Saturday lows 45-49. (seasonal averages high 59 low 47)

 

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Forecast for the Cascades in Lane County:

• Mostly cloudy with rain and snow showers tonight (0.10 in. of rain possible, 1-3 in. of snow possible), rain and snow shower chances decreasing to (40%) late tonight,
• Mostly cloudy with a good (50%) chance of AM rain and snow showers, showers (0.10 in. of rain possible, 1 in. of snow possible) Sunday afternoon (Mother’s Day), a good (50%) chance of rain and snow showers at night (under 0.10 in. of rain possible),
• Mostly cloudy with a good (50%) chance of showers Monday and a bit cooler, rain and snow showers Monday night,
• Then mostly cloudy with rain and snow showers and a bit cooler Tuesday and at night.
• snow level 4,000 ft. tonight, 5,000 ft. Sunday, 4,500 ft. Sunday night, 4,000 ft. Monday, 5,000 ft. Monday night, 4000 ft. Tuesday, 3,500 ft. Tuesday night.
• lows 30-28 highs 44-37.
• A good (50%) chance of rain and snow showers and a bit warmer Wednesday, a (30%) chance of evening rain and snow showers, just partly cloudy Wednesday night through Friday night,
• Then mostly sunny and a bit warmer Saturday.
• snow level 5,000 ft. Wednesday, 5,500 ft. Wednesday night, free air freezing level 7,000 ft. Thursday, 9,000 ft. Thursday night and Friday, 10,000 ft. Friday night, then 11,000 ft. Saturday.
• highs 42-59 lows 28-34.

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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 and Lane County news on-line at eugenedailynews.com.

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