Here is my weekly weather quiz question. What is a “Severe Thunderstorm?” 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 trough of low pressure (Shaded “U” shape with blue arrows) that is offshore has brought cooler moist air inland from the coast cooling us down from record highs to below average temperatures. A frontal system finally moved through to bring the change. By next Monday a frontal system will be pushing through the Pacific Northwest.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 19 in the Good category measuring Particulate Matter.

Oakridge: The Air Quality Index is 10 in the Good category measuring Ozone.

Cottage Grove: The Air Quality Index is 25 in the Good category measuring Ozone.

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

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Advisories: None At This Time.

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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 with showers likely (60%) and a slight (20%) chance of thunderstorms this afternoon (0.10 in. of rain possible, more in storms), partly cloudy with good (50%) chance of showers and a slight (20%) chance of thunderstorms this evening, mostly cloudy with a good (50%) chance of showers late tonight (under 0.10 in. of rain possible, more in storms),
• Mostly cloudy with a good (50%) chance of showers and a bit warmer Saturday (under 0.10 in. of rain possible, more in storms), just mostly cloudy late Saturday night,
• Partly cloudy and a bit warmer Sunday and in the evening, then mostly cloudy late Sunday night.
  highs 65-72 lows 48-43 warming back to 48 Sunday night.
• Mostly cloudy with a slight (20%) chance of showers and a bit cooler Monday and in the evening, mostly cloudy with a (40%) chance of showers late Monday night through Wednesday evening, a slight (20%) chance of showers late Wednesday night,
• Then mostly cloudy with a (30%) chance of showers and a bit warmer Thursday.
• highs 65-62 warming to 68 Thursday lows 50-45 warming back to 50 Wednesday night. (seasonal averages high 72 low 47).

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Eugene-Springfield Pollen Count:

Grass………. Moderate (19)

Trees………. Low (11)

Last Counted: 6/0/16

Data Courtesy of Oregon Allergy Associates.

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Forecast for Roseburg:

• Mostly cloudy with a (40%) chance of AM showers and a bit cooler this afternoon (under 0.10 in. of rain possible), a (40%) chance of showers and a slight (20%) chance of thunderstorms this evening, mostly cloudy with a slight (20%) chance of showers late tonight (under 0.10 in. of rain possible),
• Mostly cloudy with a slight (20%) chance of AM showers, partly cloudy and a bit warmer with a slight (20%) chance of showers Saturday afternoon, mostly cloudy in the evening, becoming mostly clear late Saturday night,
• Sunny and a bit warmer Sunday, mostly clear in the evening, then partly cloudy late Sunday night.
• highs 65-78 lows near 48.
• Partly cloudy with a slight (20%) chance  of showers Monday AM, mostly cloudy with a slight (20%) chance of afternoon showers, then mostly cloudy with a (30%) chance of showers Monday night through Thursday.
• highs 73-67 warming to 72 Thursday lows 50-48 warming back to 50 Wednesday night. (seasonal averages high 74 low 51).

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

• Mostly cloudy with a (40%) chance of showers this afternoon (under 0.10 in. of rain possible), a (30%) chance of showers and a slight (20%) chance of thunderstorms this evening, a slight (20%) chance of showers late tonight (under 0.10 in. of rain possible),
• Mostly cloudy with a slight (20%) chance of showers Saturday AM, partly cloudy with a slight (20%) chance of afternoon showers, mostly cloudy in the evening, mostly clear late Saturday night,
• Sunny and a bit warner Sunday, mostly clear in the evening, then partly cloudy  late Sunday night.
• highs 60-63 lows 52-50 warming back to 52 Sunday night.
• Partly cloudy with a slight (20%) chance of AM showers, mostly cloudy with a slight (20%) chance of showers Monday afternoon, then mostly cloudy with a (30%) chance of showers Monday night through Thursday.
• highs near 62 lows near 50. (seasonal averages high 61 low 50)

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Forecast for the Cascades in Lane County:

• Mostly cloudy and a bit cooler with rain and snow showers likely (70%) this afternoon and this evening (under 0.10 in. of rain possible), partly cloudy with a good (50%) chance of rain and snow showers late tonight (under 0.10 in. of rain possible),
• A good (50%) chance of AM rain and snow showers, a mix of clouds and sun and a bit warmer with a good (50%) chance of showers Saturday afternoon, just partly cloudy late Saturday night through Sunday night.
• snow level 5,000 ft. today, 4,500 ft. tonight, 4,500 ft. rising to 6.500 ft. Saturday afternoon, then 12,000 ft. Saturday night through Sunday night.
• highs 48-62 lows 35-40.
• A mix of clouds and sun with a slight (20%) chance of AM showers, a bit cooler Monday afternoon with a (30%) chance of showers, mostly cloudy with a (40%) chance of showers at night and Tuesday AM, partly cloudy and a bit cooler with a (40%) chance of rain and showers in the afternoon, a (30%) chance of rain and snow showers Tuesday night,
• A mix of clouds and sun with a (40%) chance of AM rain and snow showers, a (40%) chance of showers and a bit warmer Wednesday afternoon, mostly cloudy with a (40%) chance of showers at night,
• Then a mix of clouds and sun with a (30%) chance of showers Thursday.
• snow level above 8,000 ft. Monday, 7,500 ft. Monday night, 6,000 ft. Tuesday, 5,500 ft. Tuesday night,  5,000 ft. Wednesday, 7,000 ft. Wednesday night, then 6,500 ft. Thursday.
• highs 56-47 warming to 50 Wednesday and Thursday lows 37-34 warming back to 37 Wednesday night.

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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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