Check out my latest Eugene Daily News Weather Or Not column:
http://eugenedailynews.com/2018/04/it-was-their-month-in-history-but-why-didnt-we-know-about-them/
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Here is my weekly weather quiz question for the last time. What is “Differential Motion?” Here is the correct answer. Differential Motion is cloud motion that appears to differ relative to other nearby cloud elements, e.g. clouds moving from left to right relative to other clouds in the foreground or background. Cloud rotation is one example of differential motion, but not all differential motion indicates rotation. For example, horizontal wind shear along a gust front may result in differential cloud motion without the presence of rotation. 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 Low Pressure Trough (Shaded “U” shape with arrows) continues to control our weather. The graphics for days 1-3 show a front that is moving through. The graphics for days 3-7 show the frontal system that will move through the Pacific Northwest by today. Then a frontal system moves inland from the Oregon and California coasts late next Wednesday into early Friday morning and next front approaching the coast next Saturday morning.
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Air Quality Index:
Eugene/Springfield: The Air Quality Index is 20 in the Good category measuring Particulate Matter.
Oakridge: The Air Quality Index is 13 in the Good category measuring Particulate Matter.
Cottage Grove: The Air Quality Index is 17 in the Good category measuring Particulate Matter.
Data courtesy of Lane Regional Air Protection Agency (LRAPA)
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Advisories:
- A WINTER WEATHER ADVISORY IS IN EFFECT FROM 5 PM TODAY UNTIL 8 AM TUESDAY FOR THE NORTHERN OREGON CASCADES AND THE CASCADES IN LANE COUNTY.
- A WIND ADVISORY IS IN EFFECT FROM 11 AM UNTIL 8 PM TODAY FOR NORTHERN AND EASTERN KLAMATH COUNTY, AND WESTERN, CENTRAL, AND EASTERN LAKE COUNTY.
- A PERMANENT HEALTH ADVISORY REMAINS IN EFFECT FOR THE SOUTH UMPQUA RIVER 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 cloudy with rain this AM, showers and a bit cooler this afternoon (0.50 in. of rain possible), cloudy with evening showers likely (70%), a good (50%) chance of showers and colder tonight (0.25 in. of rain possible),
- Mostly cloudy with AM showers likely (70%), showers with a slight (20%) chance of thunderstorms and a bit cooler Monday afternoon, (0.25 in. of rain possible, small hail possible), showers likely (70%) at night (0.10 in. of rain possible),
- Mostly cloudy and a bit warmer with a (40%) chance of showers Tuesday, then a slight (20%) chance of showers Tuesday night.
- highs 52-50 warming to 53 Tuesday lows 38-36.
- Mostly cloudy with a slight (20%) chance of showers and a bit warmer Wednesday and at night,
- A mix of clouds and sun with a slight (20%) chance of showers and a bit warmer Thursday, partly cloudy Thursday night,
- A mix of clouds and sun Friday, mostly cloudy with a slight (20%) chance of showers at night,
- Then a mix of clouds and sun and a bit cooler with a (40%) chance of showers Saturday.
- highs 57-60 cooling to 58 Saturday lows 37-42. (seasonal averages high 61 low 39)
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Eugene-Springfield Pollen Count
Grass………. Low (0)
Trees………. Very High (755)
Last Counted: 4/7/18
Data Courtesy of Oregon Allergy Associates.
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Forecast for Roseburg:
- Mostly cloudy with rain this AM, showers and a bit cooler with rain this afternoon (o.50 in. of rain possible, afternoon snow level 3,500 ft.), evening showers likely (70%), rain and snow showers likely (70%) late tonight (0.10 in. of rain possible, 1 in. of snow possible, snow level 3,000 ft. falling to 2,500 ft. late at night),
- Mostly cloudy Monday AM with showers and with snow showers likely (70%) and a slight (20%) chance of thunderstorms, mostly cloudy and a bit cooler with showers and snow showers with a slight (20%) chance of thunderstorms Monday afternoon (0.25 in. of rain possible, snow level 2,000 ft. rising to 2,500 ft.), cloudy with evening rain and snow showers likely (70%), a good (50%) chance of rain and snow showers late Monday night (under 0.10 in. of rain possible, snow level 2,5009 ft.),
- A (40%) chance of rain and snow showers and a bit warmer Tuesday, then a slight (20%) chance of showers at night.
- highs 52-50 warming back to 52 Tuesday lows 40-38.
- Mostly cloudy and a bit warmer with a (30%) chance of showers Wednesday and Wednesday night,
- Partly cloudy with a slight (20%) chance of showers and a bit warmer Thursday, just partly cloudy at night,
- Mostly cloudy and a bit warmer Friday, a slight (20%) chance of showers Friday night,
- Then mostly cloudy with a (30%) chance of showers Saturday.
- highs 58-64 cooling to 62 Saturday lows 40-44. (seasonal averages high 62 low 42)
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Forecast for The South Oregon Coast Including Coos Bay and North Bend:
- Cloudy with rain this AM, showers and cooler this afternoon (0.25 in. of rain possible), evening showers likely (60%), coastal showers likely (70%) with a slight (20%) chance of thunderstorms late tonight while a (40%) chance of inland showers late at night (0.50 in. of rain possible),
- Mostly cloudy with AM showers likely (70%) and a slight (20%) chance of thunderstorms Monday, showers with a slight (20%) chance of thunderstorms and a bit cooler in the afternoon (under 0.10 in. of rain possible), evening coastal showers likely (70%) and a good (50%) chance of coastal showers late at night while inland showers likely (70%) Monday night,
- Mostly cloudy with a (30%) chance of showers and a bit warmer Tuesday, then just mostly cloudy Tuesday night.
- highs 52-50 warming back to 52 Tuesday lows 42-40.
- Mostly cloudy with a (30%) chance of showers and a bit warmer Wednesday, a slight (20%) chance of showers Wednesday night,
- Just partly cloudy and a bit warmer Thursday and at night,
- Mostly cloudy and a bit warmer Friday, a (30%) chance of showers Friday night,
- Then mostly cloudy and a bit cooler with a slight (20%) chance of showers Saturday.
- highs 55-57 cooling back to 55 Saturday lows 42-44. (seasonal averages high 55 low 43)
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Forecast for the Cascades in Lane County:
- Mostly cloudy with rain and snow and a bit cooler this afternoon (2-5 in. of snow possible), evening rain and snow showers, snow showers likely (70%) and a bit colder late tonight (0.25 in. of rain possible, 1-3 in. of snow possible),
- Mostly cloudy with AM snow showers, snow showers with a slight (20%) chance of thunderstorms and a bit cooler Monday afternoon (2-5 in. of snow possible, small hail possible), snow showers at night (2-5 in. of snow possible),
- Mostly cloudy and a bit warmer with a good (50%) chance of snow showers Tuesday, then a slight (20%) chance of rain and snow showers Tuesday night.
- snow level 4,500 ft. today, 3,500 ft. falling to 2,500 ft. late tonight, 2,500 ft. Monday and Monday night, 2,500 ft. Tuesday, then 3,000 ft. Tuesday night.
- highs 39-32 warming to 35 Tuesday lows 27-23.
- Mostly cloudy with a (30%) chance of rain and snow showers and a bit warmer Wednesday, a (40%) chance of rain and snow showers at night,
- A mix of clouds and sun with a slight (20%) chance of rain and snow showers and a bit warmer Thursday, just partly cloudy Thursday night,
- A mix of clouds and sun and a bit warmer Friday, just mostly cloudy at night,
- Then mostly cloudy and a bit cooler with a (40%) chance of rain and snow showers Saturday.
- snow level 3,000 ft. Wednesday, 4,500 ft. Wednesday night, free air freezing level 4,000 ft. Thursday, 5,500 ft. Thursday night and Friday, 6,500 ft. Friday night, then snow level 4,000 ft. Saturday.
- highs 40-47 cooling to 44 Saturday lows 26-30.
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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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