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.

________________

 

An Upper Level High Pressure Ridge (Shaded “Arch”shape with blue arrows) is taking over giving us easterly offshore airflow which heats us up to record high temperatures.  The slow cooling begins Saturday. The graphics for days 3-7 show a backdoor front attempting to move from the northeast to southwest into  Oregon Saturday through Monday.

Note: No record for Eugene Tuesday High was 98 record for date 100, Roseburg set record of 102, North Bend tied record high of 74. Prepare yourself for even hotter weather through Friday. Take proper precautions to keep hydrated and cool.

________________

 

Air Quality Index:

Eugene-Springfield: The Air Quality Index is 155 in the Unhealthy category measuring Particulate Matter.

Oakridge: The Air Quality Index is 39 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 22 in the Good category measuring Particulate Matter.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

 

__________________

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.
• 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  8 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.
• A Health Advisory remains in effect for Odel Lake, located 75 miles southeast of Eugene off highway 58  in the northwest corner of Klamath County. Water monitoring has confirmed that the level of blue-green algae toxins are below guideline values for human exposure. People should avoid swallowing water while swimming or inhaling water droplets as a result of high-speed water activities , such as water skiing or power boating, in areas where blooms are identified. Although toxins are not absorbed through the skin, people who have skin sessitivities may experience a puffy, red rash at the affected area.
• 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.

 

________________

 

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

• Sunny and Very Hot with smoke today and Thursday with record high temperatures, clear both nights,
• Mostly sunny and still Hot but a bit cooler Friday, mostly clear at night.
• highs 105-99 lows 63-57.
• Mostly sunny and still very warm with slow cooling Saturday, Sunday and Monday, mostly clear each night,
• AM sunshine, then party cloudy Tuesday afternoon.
• highs 93-89 lows 57-54. (seasonal averages high 84 low 52)

________________

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.

________________

 

Forecast for Roseburg:

• Sunny and Very Hot today, clear tonight,
• Sunny and not quite as hot but still Very Hot Thursday, mostly clear Thursday night,
• Partly cloudy and a bit cooler but still hot Friday, then partly cloudy at night.
• highs 111-101 lows 69-65.
• Partly cloudy Saturday AM, sunny and a bit cooler in the afternoon, mostly clear at night,
• Mostly sunny and a bit cooler Sunday and Monday, mostly clear both nights,
• Sunny in the AM, then mostly cloudy and a bit cooler Tuesday.
• highs 97-89 lows 62-58. (seasonal averages high 86 low 57)

_____________________

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

• Sunny and a bit warmer today, mostly clear in the evening, partly cloudy late at night and in the AM, sunny and a bit cooler Thursday afternoon, clear Thursday night,
• Sunny with patchy fog in the AM, partly cloudy and a bit cooler Friday, then mostly clear at night.
• highs 80-69 lows near 58.
• Partly cloudy and a bit cooler each day Saturday through Tuesday,
• highs 66-63 lows near 54. (seasonal averages high 65 low 53)

________________

Forecast for the Cascades in Lane County:

• Mostly sunny and Very Hot with smoke today and Thursday, mostly clear both nights,
• Mostly sunny Friday AM, partly cloudy and a bit cooler in the afternoon, then just partly cloudy at night.
• free air freezing level above 12,000 ft. tonight through Friday night.
• highs 92-87 lows 60-56.
• AM sun Saturday, partly cloudy and a bit cooler in the afternoon, a slight (20%) chance of showers and thunderstorms in the evening, just partly cloudy Saturday night,
• Partly cloudy and a bit cooler with a slight (20%) chance of showers and thunderstorms Sunday afternoon and evening, just partly cloudy late at night,
• Mostly sunny and a bit cooler with a slight (20%) chance of showers and thunderstorms Monday afternoon and evening, partly cloudy late Monday night,
• Then partly cloudy with a slight (20%) chance of showers and thunderstorms Tuesday afternoon.
• free air freezing level above 12,000 ft. Saturday AM, snow level above 8,000 ft. Saturday afternoon and evening, free air freezing level 12,000 ft. Saturday night and Sunday AM, snow level above 8,000 ft. Sunday afternoon and evening, free air freezing level above 12,000 ft.  late Sunday night, snow level above 8,000 ft. Monday afternoon and evening, free air freezing level above 12,000 ft. late Monday night and Tuesday AM, then snow level above 8,000 ft. Tuesday afternoon.
• highs 82-78 lows 53-50.

 

________________

**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.

________________

Get your local Eugene-Springfield and Lane County news on-line at eugenedailynews.com.

________________