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.

________________

An upper level low (Shaded “U” shape with blue arrows) will be keeping us in clouds and showers until Wednesday. A surface frontal system moves through the Pacific Northwest increasing the chance of precipitation overnight. Upper air high pressure (Shaded “Arch” shape with blue arrows – on first graphic) takes over Wednesday 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.

________________

Air Quality Index:

Eugene-Springfield: The Air Quality Index is 16 in the Moderate category measuring Particulate Matter.

Oakridge: The Air Quality Index is 10 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 18 in the Good category measuring Particulate Matter.

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

________________

Advisories:

• A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 10 PM TONIGHT FOR THE COAST RANGE OF NORTHWEST OREGON, THE WESTERN COLUMBIA RIVER GORGE, AND THE CENTRAL COLUMBIA RIVER GORGE.
• AN AIR STANATION ADVISORY IS IN EFFECT FROM 10 PM WEDNESDAY UNTIL 10 AM MONDAY FOR THE LOWER COLUMBIA, THE CENTRAL WILLAMETTE VALLEY, 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.

________________

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

• Cloudy with evening rain, a good (50%) chance of showers late tonight (0.10 in. of rain possible) and patchy fog late tonight and Wednesday AM with isolated AM showers, a mix of clouds and sun in the afternoon (under 0.10 in. of rain possible), partly cloudy in the evening, mostly cloudy with areas of fog and freezing fog late Wednesday night 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) night.
• lows 33-23 highs 42-36.
• 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)

_____

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).

___________________

Forecast for Roseburg:

• Cloudy with rain and snow this evening, a good (50%) chance of rain and snow showers late tonight (under 0.10 in. of rain possible, 1 in. of snow possible, snow level 1,500 ft. rising to 2,000 ft. late tonight),
• Mostly cloudy with a bit warmer with a slight (20%) chance of showers Wednesday AM (snow level 2,000 ft.), just mostly cloudy in the afternoon, partly cloudy with patchy fog and freezing fog late at night 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.
• lows 37-28 highs 46-38 warming to 40 Friday.
• 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)

________________

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

• Mostly cloudy with coastal rain this evening while inland evening rain, a (40%) chance of showers late tonight (0.10 in. of rain possible, evening snow level 2,000 ft.),
• Mostly cloudy with a slight (20%) chance of AM showers, becoming partly cloudy inland and a bit warmer Wednesday afternoon, partly cloudy in the evening, mostly cloudy with patchy fog and freezing fog late Wednesday night 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, sunny with patchy lingering afternoon fog, mostly clear with patchy evening fog, then freezing fog late at night.
• lows 40-32 highs 50-52.
• Partly cloudy with areas of fog Friday (New Year’s Day) and in the evening, areas of fog and freezing fog late Friday night,
• Partly cloudy with areas of fog and freezing fog Saturday AM, then partly cloudy with areas of fog Saturday night through Sunday 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).

________________

Forecast for the Cascades in Lane County:

• Mostly cloudy with snow this evening, cold with snow showers likely (70%) tonight (0.10 in. of rain possible, 2 in. of snow possible),
• A mix of clouds and sun Wednesday with a slight (20%) chance of isolated AM snow showers and a bit warmer, partly cloudy and cold Wednesday night,
• Mostly sunny Thursday (New Year’s Eve) and Friday (New Year’s Day), mostly clear and cold both nights.
• snow level at the surface tonight through Wednesday, free air freezing level at the surface Wednesday night, 4,500 ft. Thursday, then 6,000 ft. Thursday night,
• lows 18-11 highs 30-28.
• 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.

________________

**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.

________________

Get your local Eugene-Springfield and Lane County news on-line at eugenedailynews.com.

________________