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 taking over giving us easterly offshore airflow which keeps heating  us up to record high temperatures.  The very slow cooling begins Saturday. The graphics for days 3-7 show a backdoor front attempting to move from the northeast to southwest into  Oregon Sunday through Tuesday and another Thursday.

Note: Eugene set a new record high for today with 102, Roseburg set a new record of 108, and North Bend set a record high today of 85.  Prepare yourself for even hotter weather through Friday. Take proper precautions to keep hydrated and cool.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 192 in the Unhealthy category measuring Ozone

Oakridge: The Air Quality Index is 54 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 185 in the Unhealthy 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 11 PM THURSDAY FOR WINDS AND LOW RELATIVE HUMIDITY FOR THE WILLAMETTE VALLEY, THE NORTH OREGON COAST RANGE AND THE EAST SLOPES OF THE CENTRAL OREGON COAST RANGE.THE NORTH OREGON CASCADE FOOTHILLS, THE CENTRAL OREGON CASCADE FOOTHILLS, THE MT. HOOD NATIONAL FOREST WEST OF CASCADE CREST, AND THE WILLAMETTE NATIONAL FOREST.
• A RED FLAG WARNING IS IN EFFECT UNTIL 10 PM THIS EVENING FOR DRY AND UNSTABLE CONDITIONS FOR THE EAST SLOPES OF THE CENTRAL OREGON CASCADES, THE DESCHUTES NATIONAL FOREST, AND THE MINUS SISTERS RANGER DISTRICT.
• A RED FLAG WARNING IS IN EFFECT UNTIL 9 PM THURSDAY FOR GUSTY WINDS AND LOW RELATIVE HUMIDITIES FOR THE UMPQUA NATIONAL FOREST, THE KLAMATH BASIN AND THE FREMONT-WINEMA NATIONAL FOREST.
• A RED FLAG WARNING IS IN EFFECT UNTIL 9 PM THIS EVENING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITIES FOR THE UMPQUA BASIN AND THE EASTERN ROGUE VALLEY.
• A FIRE WEATHER WATCH IS IN EFFECT FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FROM THIS AFTERNOON THROUGH THURSDAY EVENING FOR THE UMPQUA NATIONAL FOREST.
• A HEAT ADVISORY IS IN EFFECT THROUGH  5 PM THURSDAY FOR THE NORTH OREGON COAST.
• AN EXCESSIVE HEAT WARNING IS IN EFFECT THROUGH 11 PM FRIDAY 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 11 PM TONIGHT FOR THE CURRY COUNTY COAST.
• AN EXCESSIVE HEAT WARNING IS IN EFFECT UNTIL 8 PM FRIDAY 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, 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 areas of smoke tonight and Thursday AM, mostly sunny and Very Hot with areas of smoke and record high temperatures in the afternoon, clear Thursday night,
• Mostly sunny and still Very Hot but a bit cooler Friday, mostly clear at night,
• Mostly sunny and still very warm but a bit cooler Saturday, then mostly clear Saturday night.
• lows 63-55 warming to 58 Saturday night highs 104-92.
• Mostly sunny and Hot Sunday, mostly clear at night,
• Mostly sunny and a bit cooler Monday, mostly clear Monday night,
• Mostly sunny and a bit warmer Tuesday, partly cloudy at night,
• Partly cloudy in the AM, then mostly sunny and a bit cooler Wednesday.
• highs 95-88 lows near 57. (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 tonight,
• Sunny and Very Hot Thursday, clear Thursday night,
• Sunny and a bit cooler but still hot Friday, mostly clear at night,
• Partly cloudy Saturday AM, sunny and a bit cooler, still hot, in the afternoon, then mostly clear at night.
• lows 69-62 highs 106-97.
• Mostly sunny and a bit cooler Sunday, mostly clear at night,
• Partly cloudy in the AM, sunny and a bit cooler Monday afternoon, mostly clear Monday night,
• Partly cloudy with a slight (20%) chance of showers and thunderstorms Tuesday and at night,
• Partly cloudy Wednesday AM, then sunny and a bit warmer in the afternoon.
• highs 94-89 warming to 93 Wednesday lows near 59. (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 this evening, partly cloudy late tonight and Thursday AM, sunny and a bit cooler with in the afternoon, mostly clear Thursday night with patchy coastal fog late,
• Patchy AM coastal fog, sunny and a bit cooler Friday afternoon, partly cloudy at night,
• Then partly cloudy and a bit cooler Saturday and Saturday night.
• lows 59-54 highs 72-66.
• Partly cloudy and a bit cooler Sunday through Tuesday evening, mostly cloudy late at night and Wednesday AM, then sunny Wednesday afternoon.
• highs near 64 lows near 54. (seasonal averages high 65 low 53)

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Forecast for the Cascades in Lane County:

• Mostly clear with areas of smoke tonight,
• Mostly sunny and Very Hot with areas of smoke Thursday, mostly clear at night,
• Mostly sunny and a bit cooler but still Hot Friday, partly cloudy Friday night,
• AM sun, partly cloudy and a bit cooler Saturday, then partly cloudy at night.
• free air freezing level above 12,000 ft. tonight through Saturday night.
• lows 58-52 highs 92-82.
• Partly cloudy and a bit cooler with a slight (20%) chance of showers and thunderstorms Sunday afternoon and evening, just partly cloudy late Sunday night,
• Mostly sunny start, partly cloudy and a bit cooler with a slight (20%) chance of showers and thunderstorms Monday afternoon and evening, partly cloudy 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 and a bit cooler with a slight (20%) chance of showers Wednesday afternoon.
• free air freezing level 12,000 ft. Sunday AM, snow level above 8,000 ft. Sunday afternoon and evening, free air freezing level above 12,000 ft. late 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 Tuesday night, free air freezing level above 12,000 ft. in the AM, then snow level above 8,000 ft. Wednesday afternoon.
• highs 82-76 lows 57-53.

 

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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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