Here is my weekly weather quiz question. What is the “Backwater Effect?”  The first person to post the correct answer as a comment on this page will win a week of free personalized weather forecasts tailored to your needs.  Good luck.

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An Upper Level High Pressure Ridge (Shaded “Arch” shape with blue arrows) will slowly migrate across Oregon. That means we’ll slowly warm up a bit. The graphics for days 3-7 show the next major frontal system will move over the Pacific Northwest Sunday and Monday. So far, the 4th of July looks dry with temperatures in the mid 70s. That’s a bit below normal.

 

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 27 in the Good category measuring Ozone.

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

Cottage Grove: The Air Quality Index is 26 in the Good category measuring Ozone.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

 

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Advisories:

• A Permanent Health Advisory remains in effect for the South Umpqua River and Lawson Bar. Pools in the bedrock along the rivers edge are known to develop Blue-green Algae (cyanobacterial) blooms that can be harmful to pets and people if accidental ingestion occurs. Signs have been posted along several access areas along the river.

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

• Partly cloudy tonight and Thursday AM, mostly sunny and a bit warmer in the afternoon, mostly clear at night,
• Sunny and a bit cooler Friday, partly cloudy at night and Saturday AM, mostly sunny and a bit cooler in the afternoon, then partly cloudy Saturday night.
• lows 49-52 highs 82-79.
• AM clouds and sun, mostly sunny and a bit warmer Sunday afternoon, partly cloudy at night and Monday AM, mostly sunny and a bit cooler in the afternoon, mostly clear Monday night,
• Mostly sunny Tuesday (Independence Day), clear at night,
• Then sunny and a bit warmer Wednesday.
• highs 82-77 warming to 79 Wednesday lows 54-52. (seasonal averages high 77 low 50)

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Eugene-Springfield Pollen Count

Grass………. High (49)

Trees………. Low (6)

Last Counted: 6/28/17

Data Courtesy of Oregon Allergy Associates.

 

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Forecast for Roseburg:

• Mostly clear this evening, partly cloudy late tonight,
• Mostly cloudy in the AM, sunny and a bit warmer in the afternoon Thursday and Friday, mostly clear Thursday night and Friday evening, mostly cloudy with patchy drizzle late Friday night,
• AM clouds, mostly sunny and a bit cooler Saturday, then mostly clear in the evening, partly cloudy late at night.
• lows 52-56 highs 83-80.
• Partly cloudy and a bit warmer Sunday and Sunday night,
• Mostly sunny and a bit cooler Monday and Tuesday (Independence Day), mostly clear Monday night,
• Then sunny and a bit warmer Wednesday.
• highs 85-82 warming to 84 Wednesday lows 56-58 cooling to 54 Monday night and Tuesday night. (seasonal averages high 80 low 54)

 

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

• Partly cloudy this evening, mostly cloudy late tonight,
• AM clouds, sunny Thursday afternoon, mostly clear in the evening, partly cloudy late at night and Friday AM, partly cloudy in the afternoon and evening, mostly cloudy with patchy drizzle late Friday night,
• Mostly cloudy with patchy AM drizzle, sunny Saturday afternoon, then partly cloudy Saturday night.
• lows near 53 highs near 64.
• Partly cloudy and a bit warmer Sunday, partly cloudy Sunday night,
• Partly cloudy and a bit cooler Monday, mostly clear at night,
• Then mostly sunny Tuesday (Independence Day) and Wednesday, mostly clear Tuesday night.
• highs 64-62 lows 54-52. (seasonal averages high 63 low 52)

 

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Forecast for the Cascades in Lane County:

• Mostly clear tonight,
• Mostly sunny and a bit warmer Thursday and Friday , mostly clear Thursday night and Friday night with a slight (20%) chance of isolated thunderstorm Friday evening,
• Mostly sunny and a bit cooler Saturday, then mostly clear at night.
• free air freezing level 13,000 ft. tonight, 14,000 ft. Thursday and Thursday night, 15,000 ft. Friday, snow level above 9,000 ft. Friday night, then  free air freezing level 14,000 ft.Saturday and Saturday night.
• lows 40-46 highs 75-72.
• Mostly sunny and a bit warmer Sunday and Monday (a bit cooler), mostly clear both nights,
• Sunny and a bit cooler Tuesday (Independence Day), clear at night,
• Then sunny and a bit warmer Wednesday.
• free air freezing level 15,000 ft. Sunday, 15,000 ft. falling to 14,000 ft. Sunday night, 14,000 ft. Monday and Monday night, 14,000 ft. falling to 13,000 ft. Tuesday, 13,000 ft. rising to 14,000 ft. Tuesday night, then 14,000 ft. Wednesday.
• highs 70-72 lows 46-43 warming to 45 Tuesday night.

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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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