Here is my weekly weather quiz question for the last time. What is an “okta?” Here is the correct answer. Okta is used for the measurement of total cloud cover. One okta of cloud cover is the equivalent of 1/8 of the sky covered with cloud. I’ll have a new weekly weather quiz question for you starting Monday. 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 low (“Shaded “U” shape with blue arrows) will move through the Pacific giving us showers and cool temperatures for a while.  High pressure (Shaded “Arch” shape with blue arrows on previous graphic) will move in about midweek returning some sunshine. A frontal system will approach the coast by Saturday.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 18 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 16 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 THE CLACKAMAS COVE PORTION OF THE CLACKAMAS  RIVER IN CLACKAMAS 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.
• 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.

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

• Mostly cloudy with scattered showers this evening, a good (50%) chance of showers tonight (0.25 in. of rain possible),
• A bit cooler with a good (50%) chance of showers Monday (0.10 in. of rain possible), a (40%) chance of showers at night (0.10 in. of rain possible),
• Mostly cloudy with a good (50%) chance of showers Tuesday (0.10 in. of rain possible), a slight (20%) chance of showers Tuesday night (under 0.10 in. of rain possible),
• Patchy AM fog, partly cloudy and a bit cooler Wednesday, mostly cloudy with a slight (20%) chance of rain at night.
• lows 45-40 highs 56-54.
• Mostly cloudy with a (40%) chance of  rain Thursday, a (30%) chance of rain Thursday night through Friday night (a bit warmer Friday),
• Mostly cloudy with a good (50%) chance of rain Saturday, rain likely (60%) at night,
• Then mostly cloudy and just a bit cooler with a good (50%) chance of rain Sunday.
• highs 54-57 cooling back to 54 Sunday lows 43-45. (seasonal averages high 57 low 39)

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Your Saturday College Football Forecast:

Preliminary forecasts:

Ducks vs California at Autzen Stadium– Kickoff 7:30 PM PST: Cloudy with a good (50%) chance of rain then becoming likely, 53 cooling as the game progresses.

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Beavers vs UCLA at Riser Stadium- Kickoff 1:30 PM PST: Cloudy with a good (50%) chance of rain, 53 warming to 57 as the game progresses.

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Forecast for Roseburg:

• Mostly cloudy and cooler with showers through late this evening, showers likely (60%) late tonight (0.15 in. of rain possible) and Monday (0.10 in. of rain possible), a good (50%) chance of showers Monday night (under 0.10 in. of rain possible) and Tuesday (under 0.10 in. of rain possible), a (30%) chance of showers at night with patchy fog late (under 0.10 in. of rain possible),
• Mostly cloudy with patchy AM fog Wednesday, partly cloudy in the afternoon, then mostly cloudy Wednesday night.
• lows 47-42 highs near 57.
• Mostly cloudy with a slight (20%) chance of rain Thursday, just mostly cloudy Thursday night through Friday night,
• Mostly cloudy with a (30%) chance of rain Saturday and Saturday night,
• Then showers likely (60%) Sunday.
• highs 56-60 cooling back to 56 lows near 42-46. (seasonal averages high 59 low 42)

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

• Mostly cloudy with coastal showers and a slight (20%) chance of thunderstorms while showers inland tonight (0.15 in. of rain possible),
• Showers likely (70%) Monday (under 0.10 in. of rain possible), a good (50%) chance of showers Monday night (under 0.10 in. of rain possible),
• Mostly cloudy with a good (50%) chance of showers Tuesday (under 0.10 in. of rain possible), a slight (20%) chance of showers at night (under 0.10 in. of rain possible),
• Just mostly cloudy Wednesday and Wednesday night.
• lows 48-56 cooling back to 48 Wednesday night highs near 58.
• Mostly cloudy with a slight (20%) chance of rain Thursday, just mostly cloudy at night and Friday (a bit warmer), a slight (20%) chance of showers Friday night,
• Mostly cloudy with a good (50%) chance of rain Saturday and Saturday night,
• Then mostly cloudy with showers likely (60%) Sunday.
• highs 56-60 cooling back to 56 Sunday lows 45-50. (seasonal averages high 58 low 45).

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Forecast for the Cascades in Lane County:

• Mostly cloudy and cooler with rain and snow showers tonight (0.25 in. of rain possible, 1-2 in. of snow possible),
• Mostly cloudy and cooler with rain and snow showers Monday (0.10 in. of rain possible (0.10 in. of rain possible, 1 in. of snow possible),  a good (50%) chance of rain and snow showers at night (0.10 in. of rain possible) and Tuesday (0.10 in. of rain possible), then a (40%) chance of rain and snow showers Tuesday night,
• Just partly cloudy and warmer Wednesday,  partly cloudy with a slight (20%) chance  of rain and snow at night.
• snow level 5,000 ft. tonight, 4,500 ft. Monday, 4,000 ft. Monday night, 3,500 ft. Tuesday, free air freezing level 4,000 ft. Tuesday night, 4,500 ft Wednesday, then snow level 4,500 ft. Wednesday night.
• lows 30-24 rising to 27 Wednesday night highs 39-36 warming back to 39 Wednesday.
• Mostly cloudy and a bit warmer with a (30%) chance of rain and snow Thursday, a slight (20%) chance of rain and snow Thursday night,
• A mix of clouds and sun and a bit warmer with a slight (20%) chance of rain and snow Friday, mostly cloudy with a (40%) chance of rain at night,
• Mostly cloudy with a (40%) chance of rain Saturday, a good (50%) chance of rain Saturday night,
• Then rain and snow likely (60%) Sunday.
• free air freezing level snow level 4,500 ft. Thursday, 5,000 ft. Thursday night, 6,000 ft. Friday, 7,000 ft. Friday night and Saturday, 7,500 ft. Saturday night, then 5,500 ft. Sunday.
• highs near 42-47 cooling to near 40 Sunday lows near 32.

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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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