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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Northwesterly airflow around an Upper Level High Pressure Ridge (Shaded “Arch” shape with blue arrows) is keeping us in cooler moister air. The High will move inland warming things up toward the end of the week. The graphics for days 3-7 show the next major frontal system will move over the Pacific Northwest next Sunday and Monday.

 

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 23 in the Good category measuring Ozone.

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

Cottage Grove: The Air Quality Index is 23 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:

• Mostly cloudy this AM, clearing to mostly sunny and a bit warmer this afternoon, partly cloudy tonight,
• Partly cloudy Thursday AM, mostly sunny and a bit warmer in the afternoon and Friday, mostly clear Thursday night, then partly cloudy Friday night.
• highs 77-83 lows 49-52.
• Partly cloudy Saturday AM, mostly sunny in the afternoon, partly cloudy Saturday night,
• AM clouds and sun, mostly sunny and a bit warmer Sunday afternoon, partly cloudy at night,
• Partly cloudy Monday AM, mostly sunny and a bit cooler in the afternoon, partly cloudy Monday night,
• Then mostly sunny and a bit cooler Tuesday (Independence Day).
• highs 82-84 cooling to 76 Tuesday lows 52-49. (seasonal averages high 77 low 49)

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Eugene-Springfield Pollen Count

Grass………. High (30)

Trees………. Low (8)

Last Counted: 6/27/17

Data Courtesy of Oregon Allergy Associates.

 

 

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Forecast for Roseburg:

• Mostly cloudy this AM, partly cloudy and a bit warmer this afternoon, mostly clear tonight,
• Mostly cloudy in the AM, sunny and a bit warmer Thursday and Friday, mostly clear both nights,
• highs 80-84 lows 53-55.
• Mostly sunny and a bit cooler Saturday, mostly clear at night,
• Partly cloudy Sunday through Monday, mostly clear Monday night,
• Then mostly sunny Tuesday (Independence Day).
• highs 85-82 lows 56-58 cooling to 54 Monday night. (seasonal averages high 80 low 54)

 

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

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

 

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Forecast for the Cascades in Lane County:

• Mostly sunny and a bit cooler today, mostly clear tonight,
• Mostly sunny and a bit warmer Thursday, mostly clear Thursday night,
• Sunny and a bit warmer Friday, then mostly clear at night.
• free air freezing level 12,000 ft. rising to 13,000 ft. this afternoon, 13,000 ft. tonight, 14,000 ft. rising to 15,000 ft. Thursday afternoon, 15,000 ft. Thursday night, 15,000 ft. falling to  14,000 ft. Friday afternoon, then 14,000 ft. Friday night.
• highs 68-74 lows 42-46.
• Mostly sunny and a bit cooler Saturday, mostly clear at nights,
• Mostly sunny and a bit warmer Sunday, mostly clear at night,
• Mostly sunny and a bit cooler Monday, mostly clear at night,
• Then mostly sunny and a bit cooler Tuesday (Independence Day).
• free air freezing level 14,000 ft. Saturday, 14,000 ft. rising to 15,000 ft. Saturday night, 15,000 ft. Sunday night, then 14,000 ft. Monday through Tuesday.
• highs 70-73 cooling to 69 Tuesday lows 45-42.

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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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