Here is my weekly weather quiz question for the last time. What are “Backing Winds?” Here is the correct answer. Backing Winds are winds which shift in a counterclockwise direction with time at a given location (e.g. from southerly to southeasterly), or change direction in a counterclockwise sense with height (e.g. westerly at the surface but becoming more southerly aloft). The opposite of veering winds. I’ll have a new weekly weather quiz question for you starting Monday. 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) is still dominating our weather picture.  The very slow cooling began Friday with some onshore airflow, but we start to warm back up pretty quickly by Sunday. The graphics for days 1-3 show a backdoor front attempting to move from the northeast to southwest into Oregon.

Note: Eugene set a new record high for Wednesday with 102 and the same for Thursday, Roseburg set a new record of 108 Wednesday and again Thursday, and North Bend set a record high Wednesday of 85 but no record Thursday.  We’ve lost the triple digit highs, but you should still take proper precautions to keep hydrated and cool.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 36 in the Good category measuring Particulate Matter.

Oakridge: The Air Quality Index is 41 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 37 in the Good category measuring Ozone.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

 

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Advisories:

• A RED FLAG WARNING IS IN EFFECT FROM 1 PM UNTIL 11 PM SUNDAY FOR THE KLAMATH BASIN, AND THE FREMONT-WINEMA NATIONAL FOREST.
• A FIRE WEATHER WATCH IS IN EFFECT FROM MONDAY MORNING THROUGH MONDAY EVENING FOR ABUNDANT LIGHTNING ON DRY FUELS FOR THE UMPQUA NATIONAL FOREST.
• A FIRE WEATHER WATCH IS IN EFFECT FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR ABUNDANT LIGHTNING ON DRY FUELS FOR THE KLAMATH BASIN, AND THE FREMONT-WINEMA NATIONAL FOREST.
• AN AIR  QUALITY ALERT IS IN EFFECT UNTIL 7 PM TUESDAY FOR BENTON COUNTY, CLACKAMAS COUNTY, CLATSOP COUNTY, COLUMBIA COUNTY, HOOD RIVER COUNTY, LANE COUNTY, LINCOLN COUNTY, LINN COUNTY, MARION COUNTY, MULTNOMAH COUNTY, POLK COUNTY, TILLAMOOK COUNTY, WASHINGTON COUNTY, YAMHILL COUNTY,  CLARK COUNTY, DESCHUTTES COUNTY AND JEFFERSON COUNTY.
• The Oregon Health Authority issued a Health Advisory for Coffenbury Lake, located at Fort Stevens State Park about five miles northwest of US-101 ALT, Northwest Ridgefield Road near Warrenton in Clatsop County. Water monitoring has confirmed the presence of blue-green algae that can produce toxins in Coffenbury Lake. These blue-green algae levels are likely to be associated with dangerous cyanotoxin concentrations in the water that can be harmful to humans and animals.  People should always avoid areas with visible scum that looks foamy, scummy, thick like paint, pea-green, blue-green or brownish-red. Swimming and high-speed water activities such as water skiing or power boating where ingestion and inhalation exposure can occur are discouraged. Swallowing or inhaling water droplets as a result of these water activities in areas where a bloom has been identified or an advisory issued, can expose people to the toxins that can be produced. Although toxins are not absorbed through the skin, people with skin sensitivities who come into contact with a bloom may experience a puffy, red rash at the affected area. Drinking water directly from Coffenbury Lake at this time is especially dangerous. OHA Public Health Division officials advise campers and other recreational visitors that toxins cannot be removed by boiling, filtering or treating water with camping-style filters.
• 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:

• Mostly clear tonight,
• Mostly sunny and a bit warmer with patchy smoke Sunday afternoon, mostly clear with patchy smoke at night,
• AM clouds with patchy smoke, mostly sunny and a bit warmer with patchy smoke Monday afternoon, partly cloudy with patchy smoke Monday night,
• Partly cloudy Tuesday and at night.
• lows 55-58 highs 92-94.
• Partly cloudy Wednesday AM, mostly sunny and a bit cooler in the afternoon, mostly clear Wednesday night,
• Mostly sunny and a bit cooler Thursday, Friday, and Saturday, mostly clear Thursday night, partly cloudy Friday night.
• highs 92-89 lows near 58. (seasonal averages high 84 low 52)

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Eugene-Springfield Pollen Count

Grass………. Low (3)
Trees………. Low (3)
Last Counted: 8/2/17
Data Courtesy of Oregon Allergy Associates.
Note: It would seem the pollen season is over.

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Forecast for Roseburg:

• Mostly cloudy this evening, partly cloudy late tonight with patchy smoke,
• AM sun, partly cloudy and a bit warmer with patchy smoke Sunday afternoon, a slight (20%) chance of isolated evening thunderstorms, patchy smoke late at night,
• Partly cloudy with patchy AM smoke, a slight (20%) chance of isolated thunderstorms Monday afternoon through Tuesday afternoon (a bit warmer) and Tuesday night.
• lows 59-64 highs 95-97.
• Partly cloudy and a bit cooler with a slight (20%) chance of isolated thunderstorms Wednesday through Thursday evening, mostly clear Thursday night,
• AM sun, partly cloudy Friday afternoon, mostly clear at night,
• Then mostly sunny Saturday.
• highs 95-93 lows near 62. (seasonal averages high 86 low 57)

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

• Mostly cloudy with patchy coastal fog late while patchy inland smoke tonight,
• Mostly cloudy Sunday with patchy inland smoke, partly cloudy in the evening and mostly cloudy with patchy coastal fog late at night while patchy inland smoke Sunday night,
• Mostly cloudy with patchy AM fog while patchy inland AM smoke, mostly sunny Monday afternoon, partly cloudy at the shore while party cloudy with a slight (20%) chance of inland thunderstorms at night,
• Then partly cloudy with a slight (20%) chance of isolated thunderstorms Tuesday and Tuesday night.
• lows near 55 highs 67-65 warming back to 67 Tuesday.
• Partly cloudy with a slight (20%) chance of isolated thunderstorms Wednesday, mostly cloudy with a slight (20%) Wednesday night and Thursday, then just partly cloudy Thursday night through Saturday.
• highs near 65 lows near 55. (seasonal averages high 65 low 53)

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Forecast for the Cascades in Lane County:

• Partly cloudy tonight,
• Mostly sunny in the AM, partly cloudy with patchy smoke Sunday afternoon, partly cloudy with a slight (20%) chance of evening showers and thunderstorms, patchy smoke at night,
• Partly cloudy with patchy smoke and a slight (20%) chance of showers and thunderstorms Monday afternoon and evening, just partly cloudy late Monday night,
• Partly cloudy with a slight (20%) chance of showers and thunderstorms Tuesday afternoon and in the evening, partly cloudy late at night.
• free air freezing level above 12,000 ft. tonight and Sunday, snow level above 8,000 ft. Sunday night through Tuesday evening, free air freezing level above 12,000 ft. late Tuesday night.
• lows 55-53 highs near 80.
• Partly cloudy with a slight (20%) chance of showers and thunderstorms Wednesday afternoon through Thursday evening, partly cloudy Thursday night,
• Partly cloudy with a slight (20%) chance of afternoon showers and thunderstorms Friday and in the evening, just partly cloudy late at night,
• Then partly cloudy with a slight (20%) chance of showers and thunderstorms Saturday afternoon.
• free air freezing level above 12,000 ft. Wednesday AM, snow level above 8,000 ft. Wednesday afternoon and evening, free air freezing level late Wednesday night through Thursday evening, free air freezing level 12,000 ft. late Thursday night and Friday AM, snow level above 8,000 ft. Friday afternoon, free air freezing level above 12,000 ft. Friday night and Saturday AM, then snow level above 8,000 ft. Saturday afternoon.
• highs near 80 lows near 53.

 

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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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