Here is my new weekly weather quiz question. What is “Rayleigh Scattering?” 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. Good luck.

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An upper level high (Shaded “Arch” shape with blue arrows) is building over us and that means sunshine and warming temperatures for a while.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 72 in the Good category measuring Particulate Matter.

Oakridge: The Air Quality Index is 13 in the Moderate category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 28 in the Good category measuring Particulate Matter.

Data courtesy of Lane Regional Air Protection Agency (LRAPA).

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Advisories:

• A HEALTH ADVISORY CONTINUES FOR SUNSET BAY STATE PARK BEACH LOCATED IN COOS COUNTY FOR HIGHER-THAN-NORMAL FECAL BACTERIA WHICH CAN RESULT IN DIARRHEA, STOMACH CRAMPS, SKIN RASHES, UPPER RESPIRATORY INFECTIONS AND OTHER ILLNESSES. DIRECT CONTACT WITH THE WATER – ESPECIALLY BY CHILDREN AND THE ELDERLY, WHO MAY BE VULNERABLE TO WATERBORNE BACTERIA – SHOULD BE AVOIDED IN THIS AREA UNTIL THE ADVISORY IS LIFTED. VISITORS SHOULD AVOID WADING IN NEARBY CREEKS, POOLS OF WATER ON THE BEACH, OR IN DISCOLORED WATER AND STAY CLEAR OF WATER RUNOFF FLOWING INTO THE OCEAN.
• A HEALTH ADVISORY CONTINUES FOR UPPER KLAMATH LAKE AND AGENCY LAKE DOWN TO KENO DAM, LOCATED JUST NORTH OF KLAMATH FALLS ALONG HIGHWAY 97 IN KLAMATH COUNTY. WATER MONITORING BY THE USGS HAS CONFIRMED THE PRESENCE OF BLUE-GREEN ALGAE TOXINS WHICH CAN BE HARMFUL TO HUMANS AND ANIMALS. SWALLOWING, INHALING OR SKIN CONTACT WITH WATER DROPLETS SHOULD BE AVOIDED.

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

• Clear tonight,
• Sunny and warmer Thursday and Friday, clear at night,
• A mix of clouds and sun in the AM, mostly sunny and just a bit cooler Saturday afternoon, partly cloudy at night.
• lows 50-55 highs 88-92 cooling back to 88 Saturday.
• A mix of clouds and sun Sunday AM, mostly sunny in the afternoon, mostly clear at night,
• Mostly sunny Monday AM, a mix of clouds and sun and cooler with a slight (20%) chance of rain in the afternoon, mostly cloudy with a slight (20%) chance of showers late Monday night,
• Partly cloudy with a slight (20%) chance of showers Tuesday, just partly Tuesday night and Wednesday afternoon.
• highs 84-77 lows near 53. (seasonal averages high 79 low 48)

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Forecast for the Umpqua Basin including Roseburg:

• Clear tonight,
• Sunny and warmer Thursday and Friday, clear at night,
• Mostly sunny Saturday, then mostly clear at night.
• lows 55-58 highs 94-98 cooling to 92 Saturday.
• Mostly sunny and cooler Sunday and Monday, mostly clear at night,
• Then partly cloudy and cooler with a slight (20%) chance of showers Tuesday through Wednesday.
• highs 89-78 lows 47-50. (seasonal averages high 80 low 52)

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Forecast for the South Oregon Coast including Coos Bay and North Bend:

• Mostly clear tonight,
• Sunny Thursday and Friday, mostly clear at night,
• Mostly sunny Saturday, then mostly clear at night.
• lows near 55 highs near 67.
• Mostly sunny Sunday and Monday, mostly clear Sunday night, partly cloudy late Monday night,
• Partly cloudy Tuesday through Wednesday with a slight (20%) chance of showers.
• highs near 67 lows 53-48. (seasonal averages high 65 low 51).

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Forecast for the Cascades in Lane County:

• Clear tonight,
• Sunny and warmer Thursday and Friday, clear at night,
• Mostly sunny Saturday AM, then partly cloudy and a bit cooler in the afternoon and Saturday night.
• free air freezing level 15,000 ft. tonight through Saturday night.
• lows 46-50 highs 78-83 cooling to back to 78 Saturday.
• Mostly sunny, but cooler Sunday, mostly clear at night,
• Mostly sunny Monday AM, partly cloudy and a bit cooler in the afternoon, partly cloudy with a slight (20%) chance of showers late Monday night through Wednesday.
• free air freezing level 14,000 ft. Sunday, 15,000 ft. Sunday night and Monday, snow level above 8,000 ft. Monday night through Wednesday.
• highs 74-64 lows near 48.

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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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