Here is my new weekly weather quiz question. What is “Deep Percolation Loss?” 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 be keeping us in clouds and showers through this morning. A surface frontal system moved  in overnight for our last chance of rain for a while. Upper air high pressure (Shaded “Arch” shape with blue arrows – on first graphic) takes over later today clearing the skies for some drying time, but also colder temperatures. Local skiers continue to rejoice. The mountains have a lot of new snow and Willamette Pass, Hoodoo and Mt. Ashland are all open. Check their websites for updates.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 15 in the Moderate category measuring Particulate Matter.

Oakridge: The Air Quality Index is 17 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 14 in the Good category measuring Particulate Matter.

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

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Advisories:

• A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 4 AM TODAY FOR THE EASTERN DOUGLAS COUNTY FOOTHILLS AND JACKSON COUNTY,
• AN AIR STAGNATION ADVISORY IS IN EFFECT FROM 10 PM TONIGHT UNTIL 10 AM MONDAY FOR THE LOWER COLUMBIA, THE CENTRAL WILLAMETTE VALLEY, AND THE SOUTH WILLAMETTE VALLEY,
• A FROST ADVISORY IS IN EFFECT FROM 2 AM UNTIL 8 AM THURSDAY FOR THE SOUTH CENTRAL OREGON COAST AND THE CURRY COUNTY COAST.
• A FREEZE WATCH IS IN EFECT FROM LATE THURSDAY NIGHT THROUGH SATURDAY MORNING FOR THE SOUTH CENTRAL OREGON COAST AND THE CURRY COUNTY COAST.

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Forecast for the Southern and lower Mid Willamette Valley including Eugene-

• Cloudy with a slight (20%) chance of showers with patchy fog this AM, a mix of clouds and sun this afternoon (under 0.10 in. of rain possible), partly cloudy this evening, mostly cloudy with areas of fog and freezing fog late tonight and Thursday AM, mostly cloudy and a bit cooler with patchy lingering afternoon fog and areas of fog and freezing fog late Thursday night (New Year’s Eve) through Friday (New Year’s Day) and Friday night.
• highs 42-36 lows 25-23.
• Mostly cloudy with areas of AM and late night fog and freezing fog again Saturday through Monday AM, mostly cloudy and a bit warmer with patchy fog and a slight (20%) chance of rain Monday afternoon through Tuesday.
• highs 35-40 lows 23-28. (seasonal averages high 45 low 33)

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Home Wood Heating Advisory:

Eugene-Springfield: YELLOW– Caution is Advised.

Oakridge:  YELLOW– Caution is Advised.

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

Advisory Courtesy of Lane Regional Air Protection Agency (LRAPA).

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Forecast for Roseburg:

• Mostly cloudy with a bit warmer with a slight (20%) chance of showers this AM (snow level 1,500 ft.), just mostly cloudy this afternoon, partly cloudy with patchy fog and freezing fog late tonight and Thursday AM, mostly sunny and a bit cooler in the afternoon, mostly clear with areas of freezing fog Thursday night (New Year’s Eve),
• Patchy AM fog and freezing fog, sunny and a bit warmer Friday afternoon (New Year’s Day), mostly clear with patchy evening fog, areas of fog and freezing fog  late Friday night.
• highs 46-38 warming to 40 Friday lows 32-28.
• Patchy fog and freezing fog Saturday AM, mostly sunny with patchy lingering fog in the afternoon, mostly clear with areas of fog and freezing fog late Saturday night and Sunday AM, sunny with patchy lingering fog in the afternoon, mostly clear with patchy fog in the evening, mostly clear with areas of freezing fog late Sunday night,
• Partly cloudy with areas of fog and freezing fog Monday AM, mostly cloudy with a slight (20%) chance of rain and snow in  the afternoon, then mostly cloudy with a (30%) chance of rain and warmer Monday night and Tuesday.
• highs 42-45 lows 29-36. (seasonal averages high 48 low 36)

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

• Mostly cloudy with a slight (20%) chance of AM showers, becoming partly cloudy inland and a bit warmer this afternoon, partly cloudy this evening, mostly cloudy with patchy fog and freezing fog late tonight and Thursday AM, sunny and a bit cooler in the afternoon, mostly clear in the evening, partly cloudy with patchy fog and freezing fog Thursday night (New Year’s Eve),
•  Partly cloudy with patchy fog and freezing fog Friday AM (New Year’s Day), sunny with patchy lingering afternoon fog, mostly clear with patchy evening fog, then freezing fog late at night.
• highs 50-52 lows 34-32.
• Mostly sunny Saturday with areas of AM fog and freezing fog, patchy evening fog, mostly clear with areas of fog Saturday night and Sunday AM, sunny with patchy fog Sunday afternoon, mostly clear in the evening, partly cloudy with areas of fog and freezing fog late at night,
• Mostly cloudy with areas of AM fog and freezing fog, mostly cloudy with a slight (20%) chance of rain Monday afternoon, mostly cloudy with a (30%) chance of rain at night,
• Then cloudy with a (40%) chance of rain Tuesday.
• highs 52-50 lows 35-42. (seasonal averages high 51 low 40).

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Forecast for the Cascades in Lane County:

• A mix of clouds and sun today with a slight (20%) chance of isolated AM snow showers and a bit warmer, partly cloudy and cold tonight,
• Mostly sunny Thursday (New Year’s Eve) and Friday (New Year’s Day), mostly clear and cold both nights.
• snow level at the surface today, free air freezing level at the surface tonight, 4,500 ft. Thursday, 6,000 ft. Thursday night, 6,500 ft. Friday, then 6,000 ft. Friday night.
• highs near 28 lows near 10.
• Mostly sunny Saturday and Sunday, partly cloudy both nights,
• Partly cloudy Monday, then mostly cloudy with a slight (20%) chance of rain and snow Monday night and Tuesday.
• free air freezing level 5,000 ft. Saturday, 4,500 ft. Saturday night, at the surface Sunday, 4,000 ft. Sunday night, 4,500 ft. Monday and Monday night, then 4,000 ft. Tuesday.
• highs 28-32 lows 14-18.

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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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