Here is my weekly weather quiz question for the last time. What are “Sastrugi?” Here is the correct answer. Sastrugi are ridges of snow formed on a snow field by the action of the wind. 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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As the upper level low (Shaded “U” shape with blue arrows) slides away to the east a high pressure ridge (Shaded “Arch” shape with blue arrows) takes over for the week. A frontal system slid through the Pacific Northwest producing light rain and drizzle and cooled us off for Mother’s Day. Another frontal system moves down from Canada Thursday returning the chance of showers. Next Saturday a frontal system will move across the Pacific Northwest.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 32 in the Good category measuring Particulate Matter.

Oakridge: The Air Quality Index is 7 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 29 in the Good category measuring Particulate Matter.

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

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Advisories: None At This Time.

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Home Wood Heating Advisory:

Eugene-Springfield: GREEN – Burning is Allowed.

Oakridge: GREEN – Burning is Allowed.

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

• Mostly cloudy late tonight and Monday AM, partly cloudy in the afternoon, mostly clear Monday night,
• Partly cloudy with patchy AM fog, mostly sunny and a bit warmer Tuesday afternoon, then mostly clear at night,
• Mostly sunny and a bit warmer Wednesday, then mostly clear at night.
• lows 40-46 highs 66-80.
•  Mostly sunny and a bit cooler Thursday, partly cloudy with a slight (20%) chance of showers late Thursday night,
• Partly cloudy and a bit cooler with a slight (20%) chance of showers Friday AM, a (40%) chance of showers and a slight (20%) chance of thunderstorms in the afternoon and evening, mostly cloudy with a (40%) chance of showers late Friday night,
• Mostly cloudy and a bit cooler with a slight (20%) chance of showers Saturday and in the evening,  just mostly cloudy late at night,
• Then a mix of clouds and sun Sunday.
• highs 78-70 lows 47-50 cooling back to 47 Saturday night. (seasonal averages high 66 low 43.)

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Eugene-Springfield Pollen Count:

Grass………. Moderate (12)

Trees………. Moderate (55)

Last Counted: 5/06/16

Data Courtesy of Oregon Allergy Associates.

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Forecast for Roseburg:

• Mostly cloudy tonight,
• Partly cloudy Monday AM, sunny and a bit warmer Monday afternoon, Tuesday and Wednesday, clear each night.
• lows 45-50 highs 72-85.
• Mostly sunny and a bit warmer Thursday, mostly clear at night,
• Partly cloudy with a (40%) chance of AM showers, a (40%) chance of showers and a slight (20%) chance of thunderstorms Friday afternoon and a bit cooler, mostly cloudy with a (30%) chance of showers and a slight (20%) chance of thunderstorms in the evening, a (30%) chance of showers late Friday night,
• Mostly cloudy and a bit cooler with a slight (20%) chance of showers Saturday and Saturday night,
• Then mostly cloudy Sunday.
• highs 86-76 lows near 50. (seasonal averages high 69 low 46).

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Forecast for The South Oregon Coast Including Coos Bay and North Bend:

• Mostly cloudy tonight,
• Partly cloudy Monday AM, sunny and a bit warmer in the afternoon, Tuesday and Wednesday (a bit cooler), clear each night.
• lows 46-50 highs 62-73 cooling to 68 Wednesday.
• Mostly sunny and a bit cooler Thursday, partly cloudy at night,
• Partly cloudy with a good (50%) chance of showers Friday AM, a (40%) chance of showers with a slight (20%) chance of thunderstorms in the afternoon, cloudy with a (30%) chance of showers and a slight (20%) chance of thunderstorms in the evening, a (30%) chance of showers late Friday night,
• Mostly cloudy with a slight (20%) chance of showers Saturday and Saturday night,
• Then just mostly cloudy Sunday.
• highs 64-62 lows near 50. (seasonal averages high 58 low 46)

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Forecast for the Cascades in Lane County:

• Partly cloudy this evening, mostly cloudy with a slight (20%) chance of showers and colder late tonight,
• Partly cloudy Monday AM, mostly sunny and a bit warmer in the afternoon, mostly clear Monday night,
• Sunny and a bit warmer Tuesday, mostly clear at night,
• Mostly sunny Wednesday, then mostly clear Wednesday night.
• free air freezing level 12,000 ft. falling to 8,000 ft. late tonight, 8,000 ft. rising to 9,000 ft. Monday afternoon, 9,000 ft. Monday night, 9,000 ft. rising to 10,000 ft. Tuesday, 10,000 ft. rising to 11,000 ft. Tuesday night through Wednesday night.
• lows 32-40 highs 59-66.
• Mostly sunny and a bit warmer Thursday, partly cloudy with a slight (20%) chance of showers at night,
• Partly cloudy with a slight (20%) chance of showers Friday AM, a (40%) chance of showers and a slight (20%) chance of thunderstorms in the afternoon and evening, mostly cloudy with a slight (20%) chance of showers late Friday night and Saturday (a bit cooler), mostly cloudy with a slight (20%) chance of evening showers, partly cloudy with a slight (20%) chance of showers late Saturday night and Sunday.
• free air freezing level 11,000 ft. Thursday, then snow level above 8,000 ft. Thursday night through Saturday, then 8,000 ft. Saturday night and Sunday.
• highs 68-59 lows 43-40.

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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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