Here is my new weekly weather quiz question. What is the “dew point?”  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 low pressure trough (Shaded “U” shape with blue arrows) is moving down from the Canadian coast to continue the cooler weather.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 37 in the Good category measuring Ozone.

Oakridge: The Air Quality Index is 43 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 36 in the Good category measuring Ozone.

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

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Advisories:

• A RED FLAG WARNING IS IN EFFECT UNTIL 9 PM TONIGHT FOR THE DESCHUTES NATIONAL FOREST, MINUS SISTERS RANGER STATION AND THE CENTRAL MOUNTAINS OF OREGON.
• A RED FLAG WARNING IS IN EFFECT UNTIL 9 PM TUESDAY FOR THE EAST SLOPES OF THE OF THE NORTH OREGON CASCADES AND THE LOWER COLUMBIA BASIN OF OREGON.
• A RED FLAG WARNING IS IN EFFECT UNTIL  11 PM TONIGHT THE UMPQUA NATIONAL FOREST,  THE SISKIYOU MOUNTAINS, THE SOUTHERN OREGON CASCADES, THE KLAMATH BASIN,  THE FREMONT-WINEMA NATIONAL FOREST, THE SOUTH CENTRAL OREGON DESERT INCLUDING THE BLM LAND IN IN EASTERN LAKE AND WESTERN HARNEY COUNTIES.
• A HEALTH ADVISORY HAS BEEN ISSUED 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:

• Partly cloudy tonight and Tuesday AM, mostly sunny in the afternoon, mostly clear Tuesday night,
• Mostly sunny Wednesday and Thursday, partly cloudy Wednesday night, mostly clear Thursday night.
• lows 56-50 warming to 54 Thursday night highs 86-84.
• Mostly sunny and a bit warmer Friday, partly cloudy at night,
• Partly cloudy and cooler Saturday with a slight (20%) chance of afternoon and evening showers, mostly cloudy late Saturday night,
• Then a mix of clouds and sun Sunday, mostly cloudy at night,
• Then a mix of clouds and sun with a slight (20%) chance of showers Monday afternoon.
• highs 87-82 cooling to near 80 Sunday lows near 56. (seasonal averages high 84 low 52)
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  Eugene/Springfield Pollen Count:

Trees: Low- 4

Grass: Moderate- 5*

Reading as of: 7/25/15

*Now the grass pollen season is officially over.

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Forecast for the Umpqua Basin including Roseburg:

• Partly cloudy with isolated thunderstorms this evening, mostly clear with areas of smoke late tonight,
• Sunny with areas of smoke in the AM, partly cloudy Tuesday afternoon, mostly clear Tuesday night,
• Sunny and cooler Wednesday, mostly clear at night,
• Mostly sunny and a bit warmer Thursday, then mostly clear Thursday night.
• lows 60-57 highs 88-86 warming to 92 Thursday.
• Mostly sunny and a bit warmer Friday, partly cloudy Friday night through Saturday evening, mostly cloudy late Saturday night,
• Mostly cloudy Sunday with a slight (20%) chance of thunderstorms Sunday afternoon through Monday afternoon.
• highs 92-86 lows near 60. (seasonal averages high 86 low 57)

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

• Partly cloudy this evening, mostly cloudy with patchy coastal fog late tonight and Tuesday AM, partly cloudy at the shore in the afternoon while sunny inland in the AM and partly cloudy in the afternoon, mostly clear in the evening, mostly cloudy late Tuesday night,
• Mostly cloudy Wednesday AM, sunny in the afternoon, then mostly clear Wednesday night,
• Mostly sunny Thursday, then mostly clear at night.
• lows near 56 highs 65-69.
• Partly cloudy Friday and Friday night,
• Mostly cloudy Saturday through Sunday night,
• Then mostly cloudy with a slight (20%) chance of showers Monday afternoon.
• highs 68-65 lows near 56. (seasonal averages high 65 low 53)

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Forecast for the Cascades in Lane County:

• Partly cloudy with a slight (20%) chance of showers and thunderstorms this evening, just partly cloudy late tonight,
• Mostly sunny Tuesday AM, partly cloudy and cooler in the afternoon, mostly clear Tuesday night,
• Mostly sunny Wednesday and Thursday, partly cloudy Wednesday night, mostly clear .
• snow level above 8,000 ft. tonight, free air freezing level 13,000 ft. Tuesday through Wednesday night, then 14,000 ft. Thursday and Thursday night.
• lows 49-46 warming back to 49 Thursday night highs 74-70 warming back to 74 Thursday.
• Mostly sunny in the AM, partly cloudy with a slight (20%) chance of showers and thunderstorms Friday afternoon through Saturday evening, mostly cloudy with a slight (20%) chance of showers late Saturday night,
• A mix of clouds and sun with a slight (20%) chance of showers Sunday AM, a slight (20%) chance of showers and thunderstorms and a bit warmer in the afternoon, partly cloudy with a slight (20%) chance of showers and thunderstorms in the evening, a slight (20%) chance of showers late Sunday night,
• Then a mix of clouds and sun with a slight (20%) chance of showers Monday.
• snow level above 8,000 ft. Friday through Monday.
• highs 72-66 warming to 70 Monday lows near 48.

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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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