Here is my weekly weather quiz question for the last time. What is  a “Back-Building Thunderstorm?” Here is the correct answer. Back-building Thunderstorm is a thunderstorm in which new development takes place on the upwind side (usually the west or southwest side), such that the storm seems to remain stationary or propagate in a backward direction.  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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The Jet Stream is sending a high pressure ridge (Shaded “Arch” shape with blue arrows) our way that will take over control of the Pacific Northwest weather for a while. The graphics for days 1-3 show the frontal system that fell apart as it moved into Oregon Friday. The graphics for days 3-7 more frontal systems headed for Oregon next week.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 5 in the Good category measuring Particulate Matter.

Oakridge: The Air Quality Index is 8 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 1 in the Good category measuring Particulate Matter.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

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Advisories:

• A Health Advisory HAS BEEN LIFTED  for South Tenmile Lake, located 10 miles north of North Bend in Coos County. The blue-green algae bloom is no longer present in the Coleman Arm of South Tenmile Lake. However, the Oregon Health Authority recommends that people continue to be cautious with their pets in the lake because toxins are still above the very low exposure levels established for dogs.
• A Health Advisory has been issued  for the water around Eagle Ridge County Park on Upper Klamath Lake. The park is located off Highway 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 this area of Upper Klamath Lake. These toxin concentrations can be harmful to humans and animals.
• A Health Advisory HAS BEEN LIFTED for Detroit Lake, located 46 miles SE of Salem in Marion County. Water monitoring has confirmed the level of blue-green algae toxins  in Detroit Lake are below guideline values for humans. However, the Oregon Health Authority recommends that people continue to be cautious with their pets in the lake because toxins are still 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:

• A mix of clouds and sun and a bit warmer today, partly cloudy this evening, mostly cloudy late tonight,
• Partly cloudy in the AM, mostly sunny and a bit warmer Sunday (Father’s Day), clear Sunday night,
• Mostly sunny Monday, then mostly clear Monday night.
• highs 77-86 lows 50-55.
• Mostly sunny and a bit cooler Tuesday, partly cloudy in the evening, clear late Tuesday                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               night,
• Sunny and a bit cooler Wednesday, clear at night,
• Mostly sunny Thursday, clear Thursday night,
• Then sunny and a bit warmer Friday.
• highs 79-75 warming back to 79 Friday lows near 50. (seasonal averages high 73 low 48)

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Eugene-Springfield Pollen Count:

Grass………. Moderate (9)

Trees………. Moderate (85)

Last Counted: 6/16/17

Data Courtesy of Oregon Allergy Associates.

 

 

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Forecast for Roseburg:

• Mostly cloudy this AM, partly cloudy and a bit warmer this afternoon and evening, mostly clear late tonight,
• Sunny and a bit warmer Sunday (Father’s Day), clear Sunday night,
• Mostly sunny and a bit warmer Monday, then mostly clear at night.
• highs 82-92 lows 55-58.
• Mostly sunny and a bit warmer Tuesday, mostly clear Tuesday night,
• Sunny and a bit warmer Wednesday, Thursday, and Friday, clear at night.
• highs 85-80 warming to 84 Friday lows near 53. (seasonal averages high 76 low 52)

 

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

• Mostly cloudy this AM, partly cloudy and a bit warmer this afternoon and evening, mostly clear late tonight,
• Then sunny and a bit warmer Sunday (Father’s Day) and Monday, mostly clear Sunday night and Monday evening, partly cloudy late Monday night,
• highs 67-72 lows 54-57.
• Mostly sunny and a bit cooler Tuesday, mostly clear at night,
• Sunny and a bit cooler Wednesday, clear Wednesday night,
• Sunny Thursday, clear at night,
• Then sunny and a bit warmer Friday.
• highs 70-67 warming to 72 Friday lows near 52. (seasonal averages high 62 low 51)

 

 

 

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Forecast for the Cascades in Lane County:

• Partly cloudy and a bit warmer today and tonight,
• Mostly sunny and warmer Sunday (Father’s Day) and Monday, clear both nights,
• free air freezing level 13,000 ft. rising to 14,000 ft. today, 15,000 ft. tonight, 15,000 ft. rising to 16,000 ft. Sunday, then 16,000 ft. Sunday night through Monday night.
• highs 69-82 lows 44-50.
• Mostly sunny and a bit cooler Tuesday, mostly clear Tuesday night,
• Sunny and a bit warmer Wednesday, clear at night,
• Mostly sunny and a bit warmer Thursday, clear at night,
• Then sunny and a bit warmer Friday.
• free air freezing level 16,000 ft. Tuesday, 16,000 ft. falling to 15,000 ft. late Tuesday night, 15,000 ft. falling to 14,000 ft. Wednesday, 14,000 ft. rising to 15,000 ft. Wednesday night, 15,000 ft. falling to 14,000 ft. Thursday, 14,000 ft. Thursday night, then 14,000 ft. rising to 15,000 ft. Friday.
• highs 75-70 warming back to 75 Friday lows 44-42.

 

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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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