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Check out my latest Eugene Daily News Weather Or Not Column I Wonder How The Dam Thing Works and my new Feature Story How Medical Science Changed My Life.

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We have a winner!

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Congratulations to Josh Foster for being the first person to post the correct answer my new weekly weather quiz question. Here is the question again. Please define “a warm occlusion” and no it has nothing to do with a dental overbite. Here is Josh’s correct answer: In a warm occlusion, the air mass overtaking the warm front is not as cool as the cold air ahead of the warm front, and rides over the colder air mass while lifting the warm air. There are both warm and cold occluded fronts. Josh wins a week of free personalized weather forecasts tailored to his needs. I’ll have a new weekly weather quiz question starting next 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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Advisories:

There is a Blue-Green Algae warning that continues for Dexter Reservoir and Dorena Reservoir, and now Fern Ridge Reservoir has been added to the list. Water monitoring has confirmed the presence of blue-green algae that can produce toxins, state public health officials said. The algae levels are likely associated with dangerous cyanotoxin concentrations in the water that can be harmful to humans and animals. Swallowing or inhaling water droplets, as well as skin contact with water, should be avoided according to the authorities.

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An upper level low (“U” shape with blue arrows) along the coast will continue to send disturbances our way including this frontal system that is moving toward the Pacific Northwest. The front will fall apart before it gets to us. We will warm up a bit then cool back down again. Yet another frontal system will move into Oregon over the weekend.

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The Grass Pollen Count is listed as Absent at 0 and Tree pollen is Absent at 0 as of 8/22/13 according to Oregon Allergy Associates.

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

• Partly cloudy with a slight (20%) chance of a shower this AM, partly cloudy this afternoon and evening, mostly cloudy late tonight and Wednesday AM, a mix of clouds and sun in the afternoon, partly cloudy in the evening, mostly cloudy late Wednesday night, cloudy Thursday AM, a mix of clouds and sun with a slight (20%) chance of showers in the afternoon, partly cloudy in the evening, then mostly cloudy late Thursday night.
• highs 83-80 lows 54-59.
• A mix of clouds and sun Friday and Saturday, mostly cloudy Friday night and mostly cloudy with a slight (20%) chance of showers late Saturday night and Sunday, mostly cloudy in the evening, then partly cloudy with a slight (20%) chance of showers late Sunday night.
• A mix of clouds and sun with a slight (20%) chance of showers Monday (Labor Day)
• highs 82-74 lows 57-53 warming to 56 Sunday night. (seasonal averages high 82 low 50)

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Forecast for the Umpqua Basin including Roseburg:

• Sunny today, partly cloudy this evening, mostly cloudy late tonight.
• Mostly cloudy Wednesday, then partly cloudy in the evening, mostly cloudy Wednesday night.
• Mostly cloudy with a slight (20%) chance of rain Thursday (under 0.01 in. of rain possible), then partly cloudy with a slight (20%) chance of showers Thursday night.
• highs 85-80 lows 60-62.
• Partly cloudy with a slight (20%) chance of showers Friday, just mostly cloudy Friday night and Saturday, partly cloudy with a slight (20%) chance of rain in the evening, mostly cloudy with a slight (20%) chance of rain late Saturday night.
• Mostly cloudy with a (30%) chance of rain Sunday AM, partly cloudy with a (30%) chance of showers in the afternoon and evening, mostly cloudy with slight (20%) chance of showers Sunday night.
• Mostly cloudy with a slight (20%) chance of showers Monday AM (Labor Day), then partly cloudy with a slight (20% chance of showers Monday afternoon.
• highs 83-85 cooling to near 77 Sunday and Monday lows 59-56. (seasonal averages high 83 low 55)

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

• Mostly cloudy today with patchy AM coastal fog, mostly cloudy with a slight (20%) chance of coastal rain tonight and a slight (20%) chance of evening showers inland (under 0.10 in. of rain possible) and Wednesday, a slight (20%) chance of coastal rain Wednesday night (under 0.10 in. of rain possible) while a slight (20%) chance of inland rain late at night.
• Mostly cloudy with a slight (20%) chance of rain Thursday (under 0.01 in. of rain possble), then mostly cloudy with a slight (20%) chance of showers Thursday night.
• highs 70-68 lows 57-59.
• Mostly cloudy with a slight (20%) chance of showers  Friday, just mostly cloudy Friday night and Saturday, a slight (20%) chance of showers in the evening, mostly cloudy  late Saturday night.
• Mostly cloudy with a (30%) chance of showers Sunday AM with partly cloudy skies and a (30%) chance of rain in the afternoon, then mostly cloudy with a slight (20%) chance of showers Sunday night and Monday (Labor Day).
• highs 68-64 lows 56-53. (seasonal averages high 66 low 53)

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Forecast for the Cascades of Lane County:

• Partly cloudy today through Wednesday night.
• A mix of clouds and sun with a slight (20%) chance of showers Thursday afternoon and evening, then just partly cloudy Thursday night.
• free air freezing level 12,000 ft. today, 12,000 ft. rising to 13,000 ft. tonight, 13,000 ft. Wednesday, 13,000 ft. falling to 12,000 ft. late Wednesday night and Thursday AM, snow level 8,000 ft. Thursday afternoon and evening, then free air freezing level 12,000 ft. late Thursday night.
• highs 69-72 cooling to 69 Thursday lows near 47.
• Partly cloudy Friday and Friday evening, mostly cloudy Friday night. A mix of clouds and sun  with a slight (20%) chance of showers Saturday afternoon, partly cloudy with a slight (20%) chance of showers Saturday night and Sunday, mostly cloudy in the evening and partly cloudy late Sunday night with a slight (20%) chance of showers Sunday night.
• A mix of clouds and sun with a slight (20%) chance of showers Monday (Labor Day).
• free air freezing level 12,000 ft. rising to 13,000 ft. Friday afternoon, 13,000 ft. falling to 12,000 ft. late Friday night, then snow level above 8,000 ft. Saturday through Monday.
• highs 69-63 lows 47-43.

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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 Eugene Daily News.com.

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