Here is my weekly weather quiz question for the last time. What is a “Baroclinic leaf shield?” Here is the correct answer. A Baroclinic leaf shield is a cloud pattern on satellite images – frequently noted in advance of formation of a low pressure center. 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) will strengthen over us warming temperatures into the low 90s. The graphics for days days 1-3 show a weak frontal system moving through Monday to cool us down a bit. The graphics for days 3-7 show a frontal system trying to make an impact on us Thursday and another approaching the coast next Saturday.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 25 in the Good category measuring Particulate Matter.

Oakridge: The Air Quality Index is 17 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 23 in the Good category measuring Ozone.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

 

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Advisories:

• A FIRE WEATHER WATCH IS IN EFFECT FROM LATE MONDAY MORNING THROUGH MONDAY EVENING FOR ABUNDANT LIGHTNING ON DRY FUELS FOR THE KLAMATH BASIN, THE FREMONT-WINEMA NATIONAL FOREST, THE SOUTHERN OREGON CASCADES, THE EASTERN ROGUE VALLEY, AND FOR THE SOUTH CENTRAL OREGON DESERT INCLUDING THE BLM LAND IN EASTERN LAKE AND WESTERN HARNEY COUNTIES.
•  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 sunny and a bit warmer today, clear tonight,
• Mostly sunny and warm Sunday, mostly clear Sunday night,
• Partly cloudy in the AM, mostly sunny Monday afternoon, then mostly clear at night.
• highs 90-88 lows 59-55.
• Mostly sunny and a bit cooler Tuesday and Wednesday, mostly clear both nights,
• Then mostly sunny and a bit warmer Thursday and Friday, mostly clear Thursday night.
• highs 85-82 lows 54-52. (seasonal averages high 84 low 52)
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Eugene-Springfield Pollen Count
Grass………. Moderate (9)
Trees………. Low (5)
Last Counted: 7/20/17
Data Courtesy of Oregon Allergy Associates.
Note: It would seem the pollen season just about over.

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Forecast for Roseburg:

• Sunny and a bit warmer today, mostly clear tonight,
• Sunny Sunday AM, partly cloudy and a bit warmer in the afternoon, partly cloudy with a slight (20%) chance of evening thunderstorms, a slight (20%) chance of showers at night,
• Partly cloudy and a bit cooler with a slight (20%) chance of thunderstorms Monday and Monday night.
• highs 93-95 lows 63-58.
• Partly cloudy with a slight (20%) chance of AM thunderstorms, just partly cloudy and a bit cooler       Tuesday afternoon, mostly clear Tuesday night,
• Mostly sunny Wednesday, mostly clear at night, Sunny and a bit warmer Thursday, clear at night,
• Then sunny and warmer Friday.
• highs 86-84 warming to 88 Friday lows near 56. (seasonal averages high 86 low 57)

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

• Sunny and a bit warmer today, mostly clear this evening, mostly cloudy with patchy fog and drizzle late tonight and Sunday AM, sunny and a bit cooler in the afternoon, mostly clear with a slight (20%) chance of evening thunderstorms, partly cloudy late Sunday night,
• highs 68-65 Sunday lows 57-55.
• A slight (20%) chance of AM showers, partly cloudy and a bit cooler Monday afternoon, mostly clear at night,
• Mostly sunny and a bit cooler Tuesday afternoon, partly cloudy Tuesday night through Wednesday evening, mostly cloudy late Wednesday night,
• AM clouds, sunny and a bit warmer in the afternoon and Friday, mostly clear Thursday night.
• highs 63-66 lows near 54. (seasonal averages high 65 low 53)

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Forecast for the Cascades in Lane County:

• Sunny and a bit warmer today, mostly clear tonight,
• AM sun, a mix of clouds and sun and a bit warmer with a slight (20%) chance of showers and thunderstorms Sunday afternoon, partly cloudy with a slight (20%) chance of showers and thunderstorms at night,
• A mix of clouds and sun and a bit cooler with a slight (20%) chance of showers and thunderstorms Monday, partly cloudy with a slight (20%) chance of showers and thunderstorms in the evening, then just partly cloudy late Monday night.
• free air freezing level above 12,000 ft. today and tonight, snow level above 8,000 ft. Sunday through Monday evening, then free air freezing level above 12,000 ft. late Monday night.
• highs 79-82 cooling back to 79 Monday lows 53-55 cooling back to 53 Monday night.
• Party cloudy and a bit cooler Tuesday with a slight (20%) chance of afternoon and evening showers and thunderstorms, partly cloudy late at night,
• Mostly sunny in the AM, partly cloudy and a bit cooler Wednesday afternoon and evening, clear late at night,
• Then sunny and a bit cooler Thursday, clear Thursday night,
• Then sunny and a bit warmer Friday,
• free air freezing level above 12,000 ft. Tuesday AM, snow level above 8,000 ft. Tuesday afternoon and evening, free air freezing level above 12,000 ft. late Tuesday night through Friday,
• highs 74-72 lows 48-46.

 

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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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