Here is my weekly weather quiz question. What are “Backing Winds?” 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 today with some onshore airflow, but we start to warm back up pretty quickly. 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 85 in the Moderate category measuring Particulate Matter.

Oakridge: The Air Quality Index is 93 in the Moderate category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 71 in the Moderate category measuring Particulate Matter.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

 

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Advisories:

• A RED FLAG WARNING IS IN EFFECT UNTIL 9 PM THIS EVENING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR THE CENTRAL MOUNTAINS OF OREGON, THE LOWER COLUMBIA BASIN OF OREGON, THE EAST SLOPES OF THE CENTRAL OREGON CASCADES, THE DESCHUTES NATIONAL FOREST, THE MINUS SISTERS RANGER DISTRICT, THE EAST SLOPES OF THE NORTHERN OREGON CASCADES, THE CENTRAL MOUNTAINS OF OREGON, THE LOWER COLUMBIA BASIN OF OREGON, THE KLAMATH BASIN, AND THE FREMONT-WINEMA 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.
• AN HEAT ADVISORY IS IN EFFECT THROUGH 9 PM TONIGHT FOR THE GREATER PORTLAND METRO AREA, THE CENTRAL WILLAMETTE VALLEY, THE SOUTH WILLAMETTE VALLEY, AND THE WESTERN COLUMBIA RIVER GORGE, THE NORTHERN OREGON CASCADE FOOTHILLS, THE CASCADE FOOTHILLS IN LANE COUNTY, THE NORTHERN OREGON CASCADES, AND THE CASCADES IN LANE COUNTY.
• AN EXCESSIVE HEAT WARNING IS IN EFFECT UNTIL 9 PM TONIGHT FOR THE CENTRAL COLUMBIA RIVER GORGE AND THE UPPER HOOD RIVER VALLEY.
• AN EXCESSIVE HEAT WARNING IS IN EFFECT UNTIL 8 PM THIS EVENING FOR CENTRAL DOUGLAS COUNTY, EASTERN CURRY COUNTY, JOSEPHINE COUNTY, THE EASTERN DOUGLAS COUNTY FOOTHILLS, JACKSON COUNTY, THE SOUTH CENTRAL OREGON CASCADES, THE SOUTHERN OREGON CASCADES, THE SISKIYOU MOUNTAINS,  THE KLAMATH BASIN, NORTHERN AND EASTERN KLAMATH COUNTY, AND WESTERN LAKE 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 Health Advisory for Odel Lake, located 75 miles southeast of Eugene off highway 58  in the northwest corner of Klamath County HAS BEEN LIFTED. Water monitoring has confirmed that the level of blue-green algae toxins are below guideline values for human exposure. However, Oregon Health officials advise recreational visitors to always be alert to signs of algae blooms in all Oregon waters, because blooms can develop and disappear throughout the season. Only a fraction of the many lakes and waterways in Oregon are monitored for blue-green algae by state, federal and local agencies, therefore, you are your own best advocate when it comes to keeping you and your family safe.
• 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 with patchy smoke tonight,
• Patchy AM smoke, mostly sunny and still hot but a bit cooler Saturday, partly cloudy Saturday night,
• Mostly sunny and a bit warmer, Hot again, Sunday, mostly clear at night,
• Mostly sunny Monday, then partly cloudy Monday night.
• lows 53-60 highs 90-95.
• Partly cloudy and a bit cooler Tuesday through Wednesday AM, mostly sunny and a bit cooler in the afternoon, mostly clear Wednesday night,
• Then mostly sunny and a bit cooler Thursday and Friday, mostly clear Thursday night.
• highs 93-89 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 clear with patchy smoke tonight,
• Sunny and a bit cooler, still hot, with patchy smoke Saturday, partly cloudy in the evening, mostly clear Saturday night with patchy smoke,
• Patchy AM smoke, sunny and a bit warmer Sunday afternoon, partly cloudy with a slight (20%) chance of evening thunderstorms, mostly clear with patchy smoke at night,
• Partly cloudy with patchy AM smoke, then a slight (20%) chance of thunderstorms Monday afternoon and at night.
• lows 57-63 highs near 95.
• Partly cloudy with a slight (20%) chance of thunderstorms Tuesday through Thursday night,
• Then sunny and a bit cooler Friday.
• highs 96-93 lows 64-62. (seasonal averages high 86 low 57)

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

• Partly cloudy with patchy coastal fog late tonight while partly cloudy with inland smoke tonight,
• Mostly cloudy with patchy AM coastal fog and sunny Saturday afternoon while sunny with patchy inland smoke, partly cloudy with patchy coastal fog late while patchy inland smoke at night,
• Mostly cloudy in the AM, mostly sunny Sunday afternoon with patchy inland smoke, partly cloudy in the evening mostly cloudy with patchy coastal fog late at night while patchy inland smoke Sunday night,
• Mostly cloudy with patchy AM fog, partly cloudy Monday afternoon, then a slight (20%) chance of thunderstorms at night.
• lows near 55 highs near 66.
• Partly cloudy with a slight (20%) chance of thunderstorms Tuesday and Tuesday night,
• Partly cloudy with a slight (20%) chance of thunderstorms Wednesday through Thursday night,
• Then Partly cloudy Friday.
• highs near 65 lows near 55. (seasonal averages high 65 low 53)

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Forecast for the Cascades in Lane County:

• Mostly clear with patchy evening smoke, mostly clear late tonight,
• AM sun, partly cloudy and a bit cooler with patchy smoke Saturday, partly cloudy at night,
• Mostly sunny in the AM, partly cloudy and a bit cooler Sunday afternoon and Sunday night,
• Partly cloudy and a bit cooler with a slight (20%) chance of showers and thunderstorms Monday afternoon and evening, then just partly cloudy late Monday night.
• free air freezing level above 12,000 ft. tonight through Sunday night, snow level above 8,000 ft. Monday and Monday night.
• lows 50-55 highs 84-80.
• Partly cloudy with a slight (20%) chance of showers and thunderstorms and a bit cooler Tuesday afternoon and evening, just partly cloudy late Tuesday night,
• Partly cloudy with a slight (20%) chance of showers and thunderstorms Wednesday afternoon and evening, partly cloudy late at night,
• Partly cloudy Thursday with a slight (20%) chance of afternoon and evening showers and thunderstorms, partly cloudy Thursday night,
• Partly cloudy with a slight (20%) chance of afternoon showers and thunderstorms Friday.
• snow level above 8,000 ft. Tuesday through Friday.
• 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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