Here is my weekly weather quiz question. What is a “Baroclinic leaf shield?” 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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Southwest airflow from the Jet Stream (Shaded “Arch” shape with blue arrows aimed Southwest to Northeast) will keep warm air headed our way. The graphics for days 1-3 show a surface low moving inland  through Washington only keeping us a bit cooler. The graphics for days 3-7 show a frontal system trying to make an impact on us Monday through Wednesday, but not succeeding.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 24 in the Good category measuring Ozone.

Oakridge: The Air Quality Index is 15 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 21 in the Good category measuring Ozone.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

 

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Advisories:

•  The Oregon Health Authority has updated the health advisory issued June 30 for Lake Billy Chinook, located about 12 miles west of Madras in Jefferson County. The update lifts the advisory on those areas of the Deschutes and Crooked River of Lake Billy Chinook arms affected by the advisory, and confines the advisory on the Metolius Arm to Perry South Cove. Water monitoring has confirmed that the level of blue-green algae toxins are below guideline values for human exposure. However, OHA recommends that people remain cautious when using the lake, particularly with pets because toxins are still well above the very low exposure levels established for dogs.
• 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,
• A slight (20%) chance of AM rain, a mix of clouds and sun Thursday afternoon, partly cloudy Thursday night,
• AM clouds, mostly sunny and a bit warmer Friday afternoon, clear at night,
• Sunny and a bit warmer Saturday, then mostly clear Saturday night.
• lows 54-50 warming to 58 Saturday night highs 80-90.
• Mostly sunny and a bit cooler Sunday and Monday, mostly clear at night,
• Partly cloudy in the AM, mostly sunny and a bit cooler Tuesday afternoon, partly cloudy at night and Wednesday AM, then mostly sunny and a bit cooler Wednesday afternoon.
• highs 87-80 lows 55-53. (seasonal averages high 84 low 52)

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Eugene-Springfield Pollen Count

Grass………. Moderate (16)

Trees………. Low (3)

Last Counted: 7/19/17

Data Courtesy of Oregon Allergy Associates.

Note: It would seem the pollen season just about over.

 

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Forecast for Roseburg:

• Partly cloudy this evening, mostly cloudy with patchy fog late tonight,
• Patchy fog and drizzle Thursday AM, partly cloudy and a bit cooler Thursday afternoon, mostly clear late at night,
• Then mostly sunny and a bit warmer Friday and Saturday, clear both nights.
• lows 56-62 highs 82-92.
• Mostly sunny Sunday with a slight (20%) chance of afternoon thunderstorms, partly cloudy with a slight (20%) chance of thunderstorms Sunday night through Monday evening, becoming mostly clear late at night,
• Then mostly sunny and a bit cooler Tuesday and Wednesday, mostly clear Tuesday night.
• highs 92-85 lows 59-56. (seasonal averages high 85 low 57)

 

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

• Partly cloudy this evening, mostly cloudy with patchy inland fog and drizzle late tonight and Thursday AM, partly cloudy in the afternoon and evening, mostly clear late Thursday night,
• Patchy AM fog, sunny Friday afternoon, mostly clear at night,
• Patchy fog Saturday AM, sunny in the afternoon, mostly clear in the evening, then partly cloudy late Saturday night.
• lows near 54 highs near 63.
• Partly cloudy Sunday AM, sunny in the afternoon, partly cloudy Sunday night and Monday, mostly clear at night,
• Mostly sunny Tuesday, then partly cloudy Tuesday night and Wednesday.
• highs 63 lows near 54. (seasonal averages high 65 low 53)

 

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Forecast for the Cascades in Lane County:

• Partly cloudy tonight and Thursday AM, mostly sunny and a bit cooler in the afternoon, clear Thursday night,
• Mostly sunny and a bit warmer Friday, clear at night,
• Sunny and a bit warmer Saturday, then mostly clear at night.
• free air freezing level above 12,000 ft. tonight through Saturday night,
• lows 44-52 highs 67-80.
• Mostly sunny in the AM, partly cloudy and a bit cooler with a slight (20%) chance of showers and thunderstorms Sunday afternoon and evening, just partly cloudy at night,
• Mostly sunny Monday AM, partly cloudy and a bit cooler with a slight (20%) chance of showers and thunderstorms in the afternoon and evening, clearing late Monday night,
• Mostly sunny and a bit cooler Tuesday with a slight (20%) chance of afternoon showers and thunderstorms, a slight (20%) change cf evening showers and thunderstorms, mostly clear late Tuesday night,
• Then mostly sunny and a bit warmer Wednesday.
• free air freezing level above 12,000 ft. Sunday AM, snow level above 8,000 ft. Sunday afternoon and evening, free air freezing level above 12,000 ft. Sunday night and Monday AM, snow level above 8,000 ft. Monday afternoon and evening, free air freezing level above 12,000 ft. late Monday night and Tuesday AM, snow level above 8,000 ft. Tuesday afternoon and evening, free air freezing level above 12,000 ft. Wednesday.
• highs 79-73 lows 52-47.

 

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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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