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 begins Friday with some onshore airflow, but we start to warm 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 today, Roseburg set a new record of 108 Wednesday and again today, and North Bend set a record high Wednesday of 85, no record today.  Still hot, but we”ll cool down a bit Friday. Take proper precautions to keep hydrated and cool.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 158 in the Unhealthy category measuring Particulate Matter.

Oakridge: The Air Quality Index is 88 in the Moderate category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 166 in the Unhealthy Groups category measuring Ozone.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

 

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Advisories:

• 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, AND CLARK COUNTY.
• AN AIR  QUALITY ALERT IS IN EFFECT UNTIL NOON SATURDAY FOR DESCHUTES COUNTY AND JEFFERSON COUNTY.
• AN EXCESSIVE HEAT WARNING IS IN EFFECT THROUGH 11 PM TONIGHT FOR THE COAST RANGE OF NORTHWEST OREGON, THE CENTRAL COAST RANGE OF WESTERN OREGON, THE LOWER COLUMBIA, THE GREATER PORTLAND METRO AREA, THE CENTRAL WILLAMETTE VALLEY, THE SOUTH WILLAMETTE VALLEY, THE WESTERN COLUMBIA RIVER GORGE, THE CENTRAL COLUMBIA RIVER GORGE, THE NORTHERN OREGON CASCADE FOOTHILLS, THE CASCADE FOOTHILLS IN LANE COUNTY, THE NORTHERN OREGON CASCADES, THE CASCADES IN LANE COUNTY, AND THE UPPER HOOD RIVER VALLEY.
• AN EXCESSIVE HEAT WARNING IS IN EFFECT UNTIL 8 PM THIS EVENING FOR THE SOUTH CENTRAL OREGON COAST, EASTERN CURRY COUNTY, DOUGLAS COUNTY, JOSEPHINE COUNTY, THE EASTERN DOUGLAS COUNTY FOOTHILLS, JACKSON COUNTY, THE SOUTH CENTRAL OREGON CASCADES, THE SOUTHERN OREGON CASCADES, THE SISKIYOU MOUNTAINS, CENTRAL DOUGLAS COUNTY, THE KLAMATH BASIN, NORTHERN AND EASTERN KLAMATH COUNTY, AND WESTERN LAKE COUNTY.
• A HEAT ADVISORY IS IN EFFECT UNTIL 8 PM THIS EVENING  FOR NORTH CENTRAL OREGON, THE EASTERN COLUMBIA RIVER GORGE, CENTRAL DOUGLAS COUNTY, THE SOUTHERN OREGON CASCADES, THE SISKIYOU MOUNTAINS, CENTRAL, AND 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:

• Clear with areas of smoke tonight and Friday AM, sunny and still Hot but cooler Friday afternoon, mostly clear at night,
• Mostly sunny and still hot but a bit cooler Saturday, clear Saturday night,
• Sunny and a bit warmer, Hot again, Sunday, then mostly clear at night.
• lows 62-54 warming to 58 Sunday night highs 95-90 warming back to 95 Sunday.
• Mostly sunny and a bit cooler Monday, partly cloudy Monday night,
• Partly cloudy Tuesday through Wednesday AM,  mostly sunny in the afternoon, mostly clear Wednesday night,
• Then mostly sunny and a bit cooler Thursday.
• highs 92-90 lows near 58. (seasonal averages high 84 low 52)

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Eugene-Springfield Pollen Count
Grass………. Moderate (18)
Trees………. Low (2)
Last Counted: 7/27/17
Data Courtesy of Oregon Allergy Associates.
Note: The pollen season is over.

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Forecast for Roseburg:

• Clear with haze and areas of smoke tonight,
• Sunny and a bit cooler but still hot Friday, mostly clear at night,
• Sunny and a bit cooler, still hot, Saturday, partly cloudy in the evening, mostly clear Saturday night,
• Sunny and a bit cooler Sunday, then partly cloudy at night.
• lows 64-60 highs 101-93.
• Partly cloudy with a slight (20%) chance of thunderstorms Monday and at night,
•  Partly cloudy and a bit cooler with a slight (20%) chance of thunderstorms Tuesday and Tuesday night,
• Partly cloudy Wednesday AM, sunny and a bit warmer in the afternoon, mostly clear at night,
• Then mostly sunny Thursday.
• highs 94-90 lows near 60. (seasonal averages high 86 low 57)

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

• Mostly clear with patchy coastal fog late tonight and Friday AM, sunny and a bit cooler in the afternoon, partly cloudy Friday night,
• Partly cloudy Saturday AM, sunny and a bit cooler in the afternoon, partly cloudy at night,
• Then partly cloudy and a bit cooler Sunday and Sunday night.
• lows 58-54 highs 69-66 warming to 68 Sunday.
• Partly cloudy and a bit warmer Monday and at night,
• Partly cloudy and a bit cooler Tuesday through Thursday morning, then sunny and a bit warmer Thursday afternoon.
• highs near 64 lows near 54. (seasonal averages high 65 low 53)

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Forecast for the Cascades in Lane County:

• Clear with areas of smoke tonight and Friday AM, sunny and a bit cooler but still Hot in the afternoon, mostly clear and cooler Friday night,
• AM sun, partly cloudy and a bit cooler Saturday and in the evening, clear late at night,
• Mostly sunny and a bit cooler with a slight (20%) chance of showers and thunderstorms Sunday afternoon, partly cloudy with a slight (20%) chance of showers and thunderstorms in the evening, then just partly cloudy late Sunday night.
• free air freezing level above 12,000 ft. tonight through Sunday night.
• lows 57-52 warming back to 55 Saturday night highs 86-80.
• Partly cloudy and a bit cooler with a slight (20%) chance of showers and thunderstorms Monday afternoon and evening, mostly clear late Monday night,
• Partly cloudy with a slight (20%) chance of showers and thunderstorms and a bit cooler Tuesday afternoon and evening, just partly cloudy at night,
• Then partly cloudy with a slight (20%) chance of showers and thunderstorms Wednesday afternoon and evening, partly cloudy at night,
• Then partly cloudy Thursday with a slight (20%) chance of afternoon showers and thunderstorms.
• snow level above 8,000 ft. Monday through Thursday.
• highs 80-78 lows 55-53.

 

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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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