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 Monday through Tuesday and another one approaching late Thursday. 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 38 in the Good category measuring Ozone.

Oakridge: The Air Quality Index is 16 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 43 in the Good category measuring Particulate 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 clear tonight,
• AM clouds, mostly sunny and a bit cooler Friday and in the evening, mostly cloudy late at night,
• Cloudy Saturday AM, partly cloudy and a bit cooler in the afternoon, mostly clear Saturday night,
• AM clouds, mostly sunny and a bit warmer Sunday afternoon, partly cloudy in the evening, then mostly cloudy late at night.
• lows 52-55 highs 79-82.
• A mix of clouds and sun Monday AM, mostly sunny and a bit cooler in the afternoon, mostly clear Monday night,
• Mostly sunny and slightly warmer Tuesday (Independence Day), clear at night,
• Sunny Wednesday, clear Wednesday night,
• Then sunny and a bit warmer Thursday.
• highs 78-80 cooling back to 78 Wednesday warming to 82 Thursday lows near 52. (seasonal averages high 78 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 with patchy fog and a slight (20%) chance of patchy drizzle late tonight,
• Mostly cloudy Friday AM, partly cloudy in the afternoon and evening, mostly cloudy with a slight (20%) chance of patchy drizzle late at night and Saturday AM, partly cloudy and a bit warmer in the afternoon, mostly clear Saturday night,
• Mostly sunny and a bit warmer Sunday, then mostly clear at night.
• lows 55-58 highs 79-85.
• Mostly sunny and a bit cooler Monday, mostly clear Monday night,
• Mostly sunny and a bit warmer Tuesday (Independence Day), mostly clear at night,
• Mostly sunny and a bit cooler Wednesday, clear at night,
• Then sunny and a bit warmer Thursday.
• highs 82-84 lows 55-57. (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 with patchy coastal fog and drizzle this evening and patchy coastal drizzle late while patchy inland fog and drizzle late tonight,
• Mostly cloudy with patchy drizzle and fog Friday AM, mostly cloudy in the afternoon, mostly cloudy with patchy drizzle late at night,
• Mostly cloudy with patchy AM drizzle, partly cloudy and a bit warmer Saturday afternoon, mostly clear in the evening, partly cloudy late Saturday night,
• Partly cloudy and a bit warmer Sunday, then partly cloudy at night.
• lows 53-55 highs 62-65.
• Partly cloudy and a bit cooler Monday and Monday night,
• Mostly sunny and a bit cooler Tuesday (Independence Day), mostly clear at night,
• Then mostly sunny Wednesday and Thursday, mostly clear Wednesday night.
• highs near 64 lows 52-54. (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 Friday while a mix of clouds and sun with a slight (20%) chance of afternoon thunderstorms along the crest, partly cloudy with a slight (20%) chance of evening showers and  thunderstorms, just partly cloudy Friday night and Saturday AM, mostly sunny and a bit cooler in the afternoon, mostly clear Saturday night,
• Sunny and a bit warmer Sunday, then mostly clear at night.
• free air freezing level 15,000 ft. tonight, snow level above 8,000 ft. Friday and Friday night, free air freezing level 14,000 ft. Saturday, 15,000 ft. rising to 16,000 ft. Saturday night, 16,000 ft. Sunday, then 16,000 ft. falling to 15,000 ft. Sunday night.
• lows 47-45 warming back to 47 Sunday night highs 75-68 warming to 76 Sunday.
• Mostly sunny and a bit cooler Monday, mostly clear at night,
• Sunny and a bit warmer Tuesday (Independence Day), clear at night,
• Sunny and a bit cooler Wednesday, clear Wednesday night.
• Then sunny and a bit warmer Thursday.
• free air freezing level 15,000 ft. Monday through Thursday.
• highs 73-75 cooling to 72 Wednesday warming to 73 Thursday lows 44-48.

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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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