Here is my weekly weather quiz question. What is “the chromosphere?” 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 Omega Blocking high pressure ridge (Shaded “Arch” shaped like the Greek letter Omega with blue arrows) is settling over the Pacific Northwest. Cold Canadian air has dried us out and given us the coldest temperatures of the season so far, particularly at night. Remember to be careful in the mountains due to the new snowfall and potentially icy driving conditions. A frontal system will be on its way to the Oregon coast Monday bringing back the slight chance of rain by Monday afternoon.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 35 in the Goodcategory measuring Particulate Matter.

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

Cottage Grove: The Air Quality Index is 30 in the Good category measuring Particulate Matter.

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

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Advisories:

• A FROST ADVISORY IS IN EFFECT FROM 10 PM TONIGHT UNTIL 8 AM SUNDAY FOR THE SOUTH CENTRAL OREGON COAST AND THE CURRY COUNTY COAST.
• A FREEZE WATCH IS IN EFFECT FROM 10 PM TONIGHT THROUGH SATURDAY MORNING FOR THE SOUTH CENTRAL OREGON COAST AND THE CURRY COUNTY COAST.
•  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:

• Clear and cold with patchy freezing fog late tonight and Saturday AM, sunny in the afternoon, clear and cold with patchy freezing fog late at night,
• A mix of clouds and sun with patchy AM freezing fog, sunny and a bit cooler Sunday afternoon, mostly clear and cold with patchy freezing fog late Sunday night and Monday AM, then mostly cloudy and a bit warmer with a slight (20%) chance of rain Monday and Monday night.
• lows 22-35 highs 45-42.
• Mostly cloudy and a bit warmer with a slight (20%) chance of rain Tuesday, a good (50%) chance of rain Tuesday night through Wednesday night,
• Rain likely (60%) Thursday, a good (50%) chance of showers at night,
• Then mostly cloudy with a (40%) chance of showers Friday.
• highs 44-49 lows near 38. (seasonal averages high 48 low 36)

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Your College Football Forecast:

The regular season is over now. Forecasts will be posted for Bowl Games when applicable.

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Forecast for Roseburg:

• Mostly clear with patchy fog this evening, areas of freezing fog late tonight and Saturday AM, sunny in the afternoon, clear with areas of freezing fog at night,
• Areas of AM freezing fog, sunny and a bit warmer Sunday afternoon, mostly clear with patchy fog Sunday night,
• Mostly cloudy and a bit warmer with a (30%) chance of rain Monday, then a slight (20%) chance of showers Monday night.
• lows 30-27 warming to 37 Monday night highs 40-46.
• Mostly cloudy and a bit warmer with a slight (20%) chance of rain Tuesday, cloudy with a (40%) chance of rain Tuesday night through Wednesday night,
• Mostly cloudy with rain Thursday, rain likely (60%) Thursday night,
• Then mostly cloudy and a bit cooler with a slight (20%) chance of showers Friday.
• highs 50-53 cooling to 49 Friday lows 42-40. (seasonal averages high 50 low 38)

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

• Clear tonight,
• Sunny Saturday and Sunday, clear Saturday night, mostly clear Sunday evening, partly cloudy late Sunday night,
• Mostly cloudy with a good (50%) chance of rain Monday, then a slight (20%) chance of showers Monday night.
• lows 33-42 highs near 53.
• Mostly cloudy and a bit warmer with a slight (20%) chance of rain Tuesday, cloudy with a good (50%) chance of rain Tuesday night,
• Rain likely (60%) Wednesday and Wednesday night,
• Rain Thursday, a good (50%) chance of rain at night,
• Then mostly cloudy with a (30%) chance of showers Friday.
• highs 56-54 lows 47-43. (seasonal averages high 52 low 41).

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Forecast for the Cascades in Lane County:

• Clear and cold tonight,
• Sunny Saturday and Sunday, clear and cold Saturday night, partly cloudy and cold Sunday night,
• Partly cloudy in the AM, then mostly cloudy with a slight (20%) chance of rain and snow Monday afternoon and Monday night.
• free air freezing level 5,000 ft. tonight, 6,000 ft. Saturday, 6,500 ft. Saturday night, 5,500 ft. Sunday, 5,000 ft. Sunday night, then 3,500 ft. Monday and Monday night.
• lows 14-24 highs near 35.
• A mix of clouds and sun and a bit warmer Tuesday, becoming mostly cloudy with a  good (50%) chance of rain and snow Tuesday night through Wednesday night,
• Rain and snow likely (60%) and a bit cooler Thursday, mostly cloudy with a good (50%) chance of rain and snow showers Thursday night,
• Then mostly cloudy and a bit cooler with a (40%) chance of rain and snow showers Friday.
• free air freezing level 6,500 ft. Tuesday, snow level 5,000 ft. Tuesday night, 6,500 ft. Wednesday, 6,000 ft. Wednesday night and Thursday, 4,000 ft. Thursday night, then 3,500 ft. Friday.
• highs 39-34 lows 32-27.

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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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