Here is my weekly weather quiz question for the last time. What is the “Bergeron Process?”  Here is the correct answer. The Bergeron Process is the process by which ice crystals in a cloud grow at the expense of supercooled liquid water droplets. 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 heating us up to uncomfortable levels. There will be some cooling Tuesday due to an Upper Level Low Pressure Trough that will follow the high by Tuesday. The graphics for days 3-7 show a frontal system approaching the Pacific Northwest Friday.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 154 in the Unhealthy category measuring Particulate Matter.

Oakridge: The Air Quality Index is 136 in the Unhealthy for Sensitive Groups category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 58 in the Good category measuring Particulate Matter.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

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Advisories:

• A  HEAT ADVISORY IS IN EFFECT FROM THIS AFTERNOON THROUGH 8 PM MONDAY EVENING 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 CASCADE FOOTHILLS, THE CASCADE FOOTHILLS IN LANE COUNTY, AND THE UPPER HOOD RIVER VALLEY.
• A RED FLAG WARNING IS IN EFFECT 11 AM TODAY UNTIL 8 PM MONDAY FOR DRY AND WINDY CONDITIONS FOR THE ENTIRE WILLAMETTE VALLEY.
• A RED FLAG WARNING IS IN EFFECT FOR SIGNIFICANTLY UNSTABLE CONDITIONS FROM 11 AM TODAY UNTIL 8 PM MONDAY FOR THE NORTHERN 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 FROM 1 PM UNTIL 9 PM TODAY FOR GUSTY WIND WITH POOR RELATIVE HUMIDITY RECOVERY FOR THE WESTERN ROGUE RIVER, THE SISKIYOU NATIONAL FOREST, THE UMPQUA BASIN, THE SOUTHERN OREGON COAST, THE UMPQUA NATIONAL FOREST AND THE SOUTHERN OREGON CASCADES, THE WESTERN ROGUE RIVER, THE SISKIYOU NATIONAL FOREST, AND THE SOUTHERN OREGON COAST.
• A RED FLAG WARNING IS IN EFFECT FROM 1 PM UNTIL 9 PM MONDAY FOR GUSTY WIND WITH POOR RELATIVE HUMIDITY RECOVERY FOR THE WESTERN ROGUE RIVER, THE SISKIYOU NATIONAL FOREST, AND THE SOUTHERN OREGON COAST, THE DESCHUTES NATIONAL FOREST AND THE MINUS SISTERS RANGER DISTRICT.
• AN AIR QUALITY ALERT IS IN EFFECT UNTIL NOON TUESDAY FOR DESCHUTES COUNTY.
• AN AIR QUALITY ALERT IS IN EFFECT UNTIL 5 PM THURSDAY FOR CENTRAL DOUGLAS COUNTY, EASTERN CURRY COUNTY, THE CURRY COUNTY COAST, JOSEPHINE COUNTY, THE EASTERN DOUGLAS COUNTY FOOTHILLS, JACKSON COUNTY, EASTERN KLAMATH COUNTY, WESTERN LAKE COUNTY, THE SOUTH CENTRAL OREGON CASCADES, THE SOUTHERN OREGON CASCADES, THE SISKIYOU MOUNTAINS, AND THE KLAMATH BASIN.
• The Oregon Health Authority issued a Health Advisory for Willow Creek Reservoir, located just east of the town of Heppner in Morrow County. Water monitoring has confirmed the presence of blue-green algae and the toxins they produce in the reservoir. These toxin concentrations 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 is 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 being produced. Although toxins are not absorbed through the skin, people who have skin sensitivities that come into contact with a bloom may experience a puffy, red rash at the affected area. Drinking water directly from Willow Creek Reservoir 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 July 28 for Howard Bay (also known locally as Howards Bay or Howard’s Bay), located in the southwest corner of Upper Klamath Lake, to include Shoalwater Bay to the north. These areas of Upper Klamath Lake are located off Oregon Route 140, 15 miles west of Klamath Falls in Klamath County. Water monitoring has confirmed the presence of blue-green algae and the toxins they produce in Howard Bay. These toxin concentrations 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 is 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 being produced. Although toxins are not absorbed through the skin, people who have skin sensitivities that come into contact with a bloom may experience a puffy, red rash at the affected area. Drinking water directly from Howard Bay and Shoalwater Bay 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.
• A Health Advisory remains in effect for Agency Lake, located just north of Klamath Falls along U.S. Highway 97 in Klamath County. Water monitoring has confirmed the presence of blue-green algae and the toxins they produce in the lake. These toxin concentrations 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 is 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 being produced. Although toxins are not absorbed through the skin, people who have skin sensitivities that come into contact with a bloom may experience a puffy, red rash at the affected area. Drinking water directly from Agency 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.
• A Health Advisory remains in effect for Willow Creek Reservoir, located just east of the town of Heppner in Morrow County. Water monitoring has confirmed the presence of blue-green algae and the toxins they produce in the reservoir. These toxin concentrations 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 is 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 being produced. Although toxins are not absorbed through the skin, people who have skin sensitivities that come into contact with a bloom may experience a puffy, red rash at the affected area. Drinking water directly from Willow Creek Reservoir 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.
• A Health Advisory remains in effect 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 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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Your College Football Forecast – Saturday 9/2: 

Ducks vs Southern Utah, at Autzen Stadium – Kickoff: 5:15 PM PDT – Too early for an a accurate weather forecast.

Beavers vs Portland State, at Reser Stadium – Kickoff: 11:00 AM PDT- Too early for an a accurate weather forecast.

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Forecast for the Southern and lower Mid Willamette Valley including Eugene-Springfield and Albany-Corvallis:

• Sunny and very hot with patchy smoke today and Monday, clear with patchy smoke both nights,
• Sunny and cooler with patchy smoke Tuesday, then mostly clear Tuesday night.
• highs 96-98 cooling to 89 Tuesday lows 62-54.
• Sunny and a bit cooler Wednesday, mostly clear at night,
• Mostly sunny and a bit warmer Thursday and Friday, mostly clear Thursday night, clear Friday night,
• Then sunny and a bit warmer Saturday.
• highs 85-90 lows 55-57. (seasonal averages high 81 low 50)

 

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Forecast for Roseburg:

• Sunny and very hot with patchy smoke today and Monday, clear with patchy smoke both nights,
• Mostly sunny and cooler with patchy smoke Tuesday, then clear with patchy smoke at night.
• highs 100-93 lows 62-57.
• Patchy AM smoke, sunny and a bit cooler Wednesday, clear at night,
• Mostly sunny with patchy smoke and a bit warmer Thursday, mostly clear with patchy smoke Thursday night,
• Then sunny with patchy smoke and a bit warmer Friday and Saturday, clear with patchy smoke both nights.
• highs 89-97 cooling to 95 Saturday lows 56-60. (seasonal averages high 83 low 54)

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

• Sunny today with patchy inland smoke, clear this evening, partly cloudy with patchy coastal fog and smoke late while patchy inland smoke tonight,
• Partly cloudy with patchy AM coastal fog and smoke, sunny Monday afternoon with patchy inland smoke, clear in the evening, partly cloudy with areas of coastal fog at night while patchy inland smoke Monday night,
• Mostly cloudy with areas of fog and patchy fog Tuesday AM, sunny and a bit cooler in the afternoon, then partly cloudy Tuesday night.
• highs 67-64 lows near 55.
• Partly cloudy Wednesday, mostly clear in the evening, partly cloudy Wednesday night and Thursday AM, sunny and a bit warmer in the afternoon, mostly clear Thursday night,
• Then mostly sunny Friday and Saturday (a bit warmer), mostly clear Friday night.
• highs 64-70 lows 54-56. (seasonal averages high 66 low 52)

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Forecast for the Cascades in Lane County:

• Sunny with areas of smoke and hot today and Monday, clear with areas of smoke both nights,
• Sunny and a bit cooler with areas of smoke Tuesday, then clear at night.
• free air freezing level above 12,000 ft. tonight through Tuesday night.
• highs 86-88 cooling to 80 Tuesday lows 60-53.
• Sunny and a bit cooler with areas of smoke Wednesday, clear with areas of smoke at night,
• Mostly sunny with areas of smoke and a bit warmer Thursday and Friday, clear with areas of smoke both nights,
• Then sunny and a bit warmer with areas of smoke Saturday.
• free air freezing level above 12,000 ft. Wednesday through Saturday.
• highs 76-82 lows 50-56.

 

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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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