Here is my weekly weather quiz question for the last time. What is “Latent Heat Flux?” Here is the correct answer. Latent Heat Flux is the flux of heat from the earth’s surface to the atmosphere that is associated with evaporation or condensation of water vapor at the surface; a component of the surface energy budget. I’ll have a new weekly weather quiz question for you starting Monday. Please remember to post your answer as a comment by clicking on “no comments /comments” in the upper right hand portion of this page under the caption, then add your comment. The first person to post the correct answer will win a week of free personalized weather forecasts tailored to your needs. The answer has to be a comment to win. An email answer will not count. Good luck.

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An upper level high (Shaded “Arch” shape with blue arrows) is returning the sunshine because it pushed a frontal system moved through the Pacific Northwest Thursday spread some much-needed rain over the area. Now we dry out again. Our next frontal system will arrive between Sunday night and Monday.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 29 in the Good category measuring Ozone.

Oakridge: The Air Quality Index is 7 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 30 in the Good category measuring Ozone.

Data courtesy of Lane Regional Air Protection Agency (LRAPA).

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Advisories:

• A HEALTH ADVISORY CONTINUES FOR SUNSET BAY STATE PARK BEACH LOCATED IN COOS COUNTY FOR HIGHER-THAN-NORMAL FECAL BACTERIA WHICH CAN RESULT IN DIARRHEA, STOMACH CRAMPS, SKIN RASHES, UPPER RESPIRATORY INFECTIONS AND OTHER ILLNESSES. DIRECT CONTACT WITH THE WATER – ESPECIALLY BY CHILDREN AND THE ELDERLY, WHO MAY BE VULNERABLE TO WATERBORNE BACTERIA – SHOULD BE AVOIDED IN THIS AREA UNTIL THE ADVISORY IS LIFTED. VISITORS SHOULD AVOID WADING IN NEARBY CREEKS, POOLS OF WATER ON THE BEACH, OR IN DISCOLORED WATER AND STAY CLEAR OF WATER RUNOFF FLOWING INTO THE OCEAN.
• A HEALTH ADVISORY CONTINUES FOR UPPER KLAMATH LAKE AND AGENCY LAKE DOWN TO KENO DAM, LOCATED JUST NORTH OF KLAMATH FALLS ALONG HIGHWAY 97 IN KLAMATH COUNTY. WATER MONITORING BY THE USGS HAS CONFIRMED THE PRESENCE OF BLUE-GREEN ALGAE TOXINS WHICH CAN BE HARMFUL TO HUMANS AND ANIMALS. SWALLOWING, INHALING OR SKIN CONTACT WITH WATER DROPLETS SHOULD BE AVOIDED.

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

• Mostly clear tonight,
• Mostly sunny Sunday AM, partly cloudy and pleasant in the afternoon, becoming mostly cloudy with a slight (20%) chance of rain late Sunday night,
• Mostly cloudy with patchy AM fog and a slight (20%) chance of showers, partly cloudy and cooler Monday afternoon, mostly clear and colder Monday night,
• Mostly sunny and a bit cooler Tuesday, then mostly clear at night.
• lows 50-53 cooling to 42 Monday night and Tuesday night highs 80-72.
• Mostly sunny Wednesday AM, partly cloudy and just a bit cooler in the afternoon and evening, mostly cloudy late Wednesday night,
• Mostly cloudy with a (40%) chance of rain Thursday afternoon through Friday, a (30%) chance of rain in the evening, a slight (20%) chance of showers late Friday night,
• Then a mix of clouds and sun with a slight (20%) chance of showers Saturday.
• highs 70-68 lows 47-49 cooling back to 47 Saturday. (seasonal averages high 76 low 46)

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Forecast for the Umpqua Basin including Roseburg:

• Mostly clear tonight,
• Sunny Sunday, partly cloudy in the evening, mostly cloudy with a slight (20%) chance of showers Sunday night and Monday AM, partly cloudy and a bit cooler in the afternoon, mostly clear and cooler Monday night,
• Mostly sunny and a bit cooler Tuesday, then mostly clear at night.
• lows 53-56 cooling to 46 Tuesday night highs 82-78 cooling to 73 Tuesday.
• Sunny Wednesday AM, partly cloudy in the afternoon and evening, then mostly cloudy with a slight (20%) chance of rain late Wednesday night through Saturday.
• highs 73-65 lows 50-54. (seasonal averages high 78 low 50)

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Forecast for the South Oregon Coast including Coos Bay and North Bend:

• Mostly clear tonight,
• Partly cloudy and a bit cooler Sunday and in the evening inland and mostly cloudy with a slight (20%) chance of showers late while a slight (20%) chance of coastal showers late Sunday night,
• Mostly cloudy with a slight (20%) chance of inland showers Monday AM, sunny and a bit warmer in the afternoon, mostly clear and cooler Monday night,
• Partly cloudy Tuesday AM, sunny and a bit cooler in the afternoon, then mostly clear Tuesday night.
• lows 54-48 highs 67-70 cooling to 65 Tuesday.
• Sunny Wednesday AM, partly cloudy in the afternoon and evening, mostly cloudy with a slight (20%) chance of rain late Wednesday night,
• Then mostly cloudy with a (30%) chance of rain Thursday through Saturday.
• highs near 64 lows near 52. (seasonal averages high 65 low 49).

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Forecast for the Cascades in Lane County:

• Clear tonight,
• Mostly sunny Sunday, partly cloudy in the evening, mostly cloudy with a slight (20%) chance of rain late at night,
• Mostly cloudy with a slight (20%) chance of showers Monday AM, partly cloudy and a bit cooler in the afternoon, mostly clear and colder Monday night,
• Mostly sunny and a bit cooler Tuesday, then mostly clear at night.
• free air freezing level 14,000 ft. tonight and Sunday, snow level above 8,000 ft. Sunday night and Monday, free air freezing level 13,000 ft. Monday night.
• lows 42-45 cooling to 34 Tuesday night highs 69-63.
• Mostly sunny Wednesday, partly cloudy Wednesday night and Thursday AM, mostly cloudy and cooler with a slight (20%) chance of rain Thursday afternoon and evening, a (40%) chance of rain late Thursday night and  Friday, a (30%) chance of rain in the evening, a (30%) chance of showers late at night,
• A mix of clouds and sun with a (30%) chance of AM showers, then a (30%) chance of rain and snow showers Saturday afternoon.
• free air freezing level 10,000 ft. Wednesday and Wednesday night, snow level above 8,000 ft. Thursday and Thursday night, 7,000 ft. Friday, 6,500 ft. Friday night, then 5,500 ft. Saturday.
• highs 69-53 lows near 38-40.

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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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