Here is my new weekly weather quiz question. What is “Zonal Flow ?”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 replacing the high pressure ridge (Shaded “Arch” shape with blue arrows). That means an increased onshore flow that will cool us down considerably.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 20 in the Good category measuring Particulate Matter.

Oakridge: The Air Quality Index is 26 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 23 in the Good category measuring Particulate Matter.

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

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Advisories:

• A RED FLAG WARNING IS IN EFFECT FROM NOON  TODAY UNTIL 8 PM TUESDAY FOR WINDY CONDITIONS AND LOW RELATIVE HUMIDITY FOR THE EAST SLOPES OF THE NORTHERN CASCADES AND THE LOWER COLUMBIA BASIN OF OREGON.

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

• Partly cloudy this AM, mostly sunny and a bit cooler this afternoon, mostly clear this evening, mostly cloudy late tonight,
• AM clouds, mostly sunny and a bit cooler Tuesday afternoon, partly cloudy in the evening, mostly cloudy late Tuesday night and Wednesday AM, partly cloudy and cooler in the afternoon, mostly cloudy Wednesday night.
• highs 89-80 lows 55-50 warming to 53.
• AM clouds, partly cloudy and a bit warmer Thursday through Friday night,
• A mix of clouds and sun and just a bit cooler Saturday and Sunday, mostly cloudy Saturday night.
• highs 82-86 cooling to 83 Sunday lows 54-57. (seasonal averages high 84 low 52)

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Forecast for the Umpqua Basin including Roseburg:

• Sunny today, mostly clear this evening, partly cloudy late tonight,
• Mostly cloudy in the AM, partly cloudy and cooler Tuesday afternoon, partly cloudy at night,
• Mostly cloudy in the AM, sunny and cooler Wednesday afternoon, then partly cloudy Wednesday night.
• highs 94-82 lows 60-55.
• Mostly sunny and a bit warmer Thursday through Saturday, partly cloudy Saturday night and Sunday.
• highs 85-88 lows 54-59. (seasonal averages high 86 low 57)

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

• Mostly cloudy with patchy coastal AM drizzle and fog today and just mostly cloudy this afternoon while partly cloudy inland in AM and sunny this afternoon, mostly cloudy at the shore tonight while mostly cloudy in the evening inland mostly cloudy late tonight inland,
• Mostly cloudy Tuesday with patchy AM coastal fog, mostly cloudy in the afternoon, partly cloudy in the evening, then mostly cloudy late Tuesday night and Wednesday AM, sunny in the afternoon, then mostly cloudy Wednesday night.
• highs near 65 lows 56-54.
• Mostly cloudy Thursday AM, mostly sunny in the afternoon, mostly clear in the evening, partly cloudy with patchy fog late Thursday night and Friday AM, just partly cloudy Friday afternoon through Saturday night,
• Then mostly cloudy Sunday AM, and sunny Sunday afternoon.
• highs near 65 lows near 55. (seasonal averages high 65 low 53)

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Forecast for the Cascades in Lane County:

• Sunny and cooler today mostly clear tonight,
• Mostly sunny Tuesday, then partly cloudy and cooler Tuesday night through Wednesday night.
• free air freezing level 14,000 ft. today and tonight, 14,000 ft. falling to 13,000 ft. Tuesday, 13,000 ft. Tuesday night, then 12,000 ft. Wednesday, and Wednesday  night.
• highs 78-68 lows 47-44.
• Then partly cloudy Thursday through Sunday.
• free air freezing level 11,000 ft. Thursday, then 12,000 ft. Thursday night through Sunday.
• highs 70-74 cooling back to 70 Sunday lows 45-48.

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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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