Here is my weekly weather quiz question for the last time. What is “coalescence?” Here is the correct answer. Coalescence is the process by which water droplets in a cloud collide and come together to form raindrops. 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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A sprawling high pressure ridge (Shaded “Arch” shape with blue arrows) sits over us keeping us cool and dry for your Sunday. An upper level low (Shaded “U” shape with blue arrows) will replace the high sending us a couple of cold fronts that will drop down through the Pacific Northwest ushering in even colder air.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 61 in the Moderate category measuring Particulate Matter.

Oakridge: The Air Quality Index is 20 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 25 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.

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

• Partly cloudy with patchy fog and areas of freezing fog this AM, mostly sunny this afternoon, partly this evening, mostly cloudy with areas of fog and freezing fog late tonight,
• Partly cloudy with areas of AM fog and freezing fog, more clouds with a slight (20%) chance of rain and a bit warmer Monday afternoon (under 0.10 in. of rain possible), evening rain, showers late Monday night (0.15 in. of rain possible),
• Mostly cloudy and colder with showers Tuesday (snow level 1,500 ft.), a slight (20%) chance of mainly evening showers, just Tuesday night.
• highs 45-48 cooling back to 45 Tuesday lows 32-38 cooling to 27 Tuesday night.
• AM clouds, mostly sunny Wednesday, just clear Wednesday night,
• Then sunny Thursday (Thanksgiving Day), Friday, and Saturday, clear each night.
• highs 40-43 lows 24-26. (seasonal averages high 50 low 37)

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Your College Football Forecast:

The Civil War Game Friday November 27th:

Ducks vs Beavers at Autzen Stadium – Kickoff 1:00 PM PST: Preliminary forecast: Sunny and cool, 36 warming 40-42 by the end of the game.

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Forecast for Roseburg:

• Clear with patchy fog this AM, partly cloudy and a bit warmer this afternoon, mostly clear this evening, partly cloudy with patchy fog and a slight (20%) chance of drizzle late tonight,
• Mostly cloudy with a slight (20%) chance of rain Monday, evening rain likely (70%), showers likely (70%) and colder Monday night (0.25 in. of rain possible),
• Mostly cloudy with rain and snow showers likely (70%) and colder Tuesday, then a (40%) chance of rain and snow showers and colder Tuesday night.
• highs 55-44 lows 40-30.
• Partly cloudy and a bit cooler Wednesday, clear and colder Wednesday night,
• Sunny and just a bit warmer Thursday (Thanksgiving Day) and Friday, clear Thursday night, mostly clear Friday night,
• Then partly cloudy and a bit warmer Saturday.
• highs 39-44 lows 22-29. (seasonal averages high 51 low 39)

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

• Partly cloudy today with patchy AM fog, partly cloudy this afternoon and evening, mostly cloudy with patchy coastal fog and a slight (20%) chance of patchy coastal drizzle tonight while patchy fog and a slight (20%) chance of patchy drizzle late tonight (under 0.10 in. of rain possible),
• Mostly cloudy with a slight (20%) chance of rain and cooler Monday (0.15 in. of rain possible), evening rain, coastal showers and a slight (20%) chance of thunderstorms late at night while inland showers late Monday night (0.40 in. of rain possible),
• Mostly cloudy with AM showers and a slight (20%) chance of thunderstorms, then rain and snow showers with a slight (20%) chance of thunderstorms and cooler Tuesday afternoon, a (40%) chance of evening showers, then a (30%) chance of rain and snow showers late Tuesday night.
• highs 59-48 lows 42-35.
• Sunny Wednesday, clear at night,
• Sunny and a bit warmer Thursday (Thanksgiving Day) and Friday, clear Thursday night, mostly clear Friday night,
• Then just partly cloudy Saturday.
• highs 45-49 lows 34-38. (seasonal averages high 54 low 42).

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Forecast for the Cascades in Lane County:

• Mostly sunny today, partly cloudy tonight,
• Partly cloudy and a bit cooler Monday, becoming mostly cloudy with evening rain and snow, rain and snow showers late Monday night,
• Mostly cloudy with snow showers and much colder Tuesday, then a good (50%) chance of snow showers Tuesday night.
• free air freezing level 11,000 ft. today, 10,000 ft. falling to 9,000 ft. late  tonight, 8,000 ft. falling to 6,500 ft. Monday, snow level 4,500 ft. falling to 3,500 ft. Monday night, then at the surface Tuesday and Tuesday night.
• highs 44-25 lows 32-15.
• Partly cloudy with a slight (20%) chance of snow showers Wednesday, mostly clear at night,
• Sunny and a bit warmer Thursday (Thanksgiving Day) and Friday and Saturday, clear each night,
• Then mostly sunny Saturday.
• snow level at the surface Wednesday, then free air freezing level at the surface Wednesday night, 4,000 ft. Thursday, 4,500 ft. Thursday night, 5,000 ft. Friday, then 4,500 ft. Friday night and Saturday.
• highs 25-34 lows 12-14.

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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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