Here is my weekly weather quiz question for the last time. What is  “Anomalous Propagation?” Here is the correct answer. ANOMALOUS PROPAGATION (AP): non-standard atmospheric temperature or moisture gradients will cause all or part of the radar beam to propagate along a non-normal path. When non-standard index-of-refraction distributions prevail, “abnormal” or “anomalous” propagation occurs. When abnormal downward bending occurs, it is called “superrefraction.” If the beam is refracted downward sufficiently, it will illuminate the ground and return signals to the radar from distances further than is normally associated with ground targets. The term “subrefraction” is applied when there is abnormal upward bending of the radar beam. Please remember to post your answer at the bottom of this page. I’ll have a new weekly weather quiz question for you starting Monday. The first person to post the correct answer 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 blue arrows) that changed our weather and some Winter precipitation moved away. An Upper Level High (Shaded “Arch” shape with blue arrows) has dried us out for a short time. The graphic for days 1-3 shows another low moving southward along the Pacific Coast Sunday. The graphic for days 3-7 shows frontal movement a week from today bringing colder air from the North to the Pacific Northwest. For mountain snow conditions at the local ski areas check out their websites or give them a call.

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Air Quality Index:

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

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

Cottage Grove: The Air Quality Index is 10 in the Good category measuring Particulate Matter.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

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Home Wood Heating Advisory:

Eugene-Springfield: GREEN – Burning is Allowed.

Oakridge: GREEN – Burning is Allowed.

*Note: Pellet stoves may be used anytime if they produce no visible emissions.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

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Advisories:

• A WINTER WEATHER ADVISORY IS IN EFFECT FROM 1 AM UNTIL 4 PM SUNDAY FOR THE COAST RANGE OF NORTHWEST OREGON AND THE NORTHERN OREGON CASCADE FOOTHILLS.
• A WINTER WEATHER ADVISORY IS IN EFFECT FROM 4 AM UNTIL 7 PM SUNDAY FOR THE CENTRAL COAST RANGE OF WESTERN OREGON, THE CASCADE FOOTHILLS IN LANE COUNTY, AND THE CASCADES IN LANE COUNTY.
• *A WINTER WEATHER ADVISORY IS IN EFFECT FROM 1 AM UNTIL 7 PM SUNDAY FOR THE NORTHERN OREGON CASCADES.
• A WINTER WEATHER ADVISORY IS IN EFFECT FROM 7 AM SUNDAY UNTIL 4 AM MONDAY FOR CENTRAL DOUGLAS COUNTY, EASTERN CURRY COUNTY, JOSEPHINE COUNTY, THE EASTERN DOUGLAS COUNTY FOOTHILLS, AND JACKSON COUNTY.
• A WINTER STORM WATCH IS IN EFFECT FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR CENTRAL DOUGLAS COUNTY, EASTERN CURRY COUNTY, JOSEPHINE COUNTY, THE EASTERN DOUGLAS COUNTY FOOTHILLS, AND JACKSON COUNTY.
• A WINTER WEATHER ADVISORY IS IN EFFECT FROM 10 AM SUNDAY UNTIL 4 AM   MONDAY FOR THE EASTERN DOUGLAS COUNTY FOOTHILLS, THE SOUTH CENTRAL OREGON CASCADES, THE SOUTHERN OREGON CASCADES, THE SISKIYOU MOUNTAINS THE KLAMATH BASIN, NORTHERN AND EASTERN KLAMATH COUNTY, AND WESTERN LAKE COUNTY.
• A WINTER STORM WARNING IS IN EFFECT FROM 10 AM SUNDAY UNTIL 4 AM MONDAY FOR JACKSON COUNTY
• 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:

• Partly cloudy this evening, becoming mostly cloudy with a slight (20%) chance of rain late tonight (0.10 in. of rain possible),
• Mostly cloudy with AM rain, showers and a bit cooler Sunday afternoon (0.25 in. of rain possible), cloudy with evening showers likely (70%), a good (50%) chance of showers late Sunday night (0.10 in. of rain possible) and Monday AM, showers likely (70%) and a bit warmer in the afternoon, mostly cloudy with evening showers likely (70%), a good (50%) chance of showers late Monday night,
• Mostly cloudy and a bit warmer with a good (50%) chance of showers Tuesday, then a slight (20%) chance of showers Tuesday night.
• lows near 34 highs 44-47.
• Mostly cloudy and a bit warmer with a slight (20%) chance of showers Wednesday, just partly cloudy Wednesday night,
• A mix of clouds and sun Thursday, mostly cloudy at night,
• Mostly cloudy with rain likely (70%) Friday and Friday night,
• Then mostly cloudy and a bit cooler with a good (50%) chance of showers Saturday.
• highs 49-47 lows 34-39. (seasonal averages high 53 low 35)

 

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Forecast for Roseburg:

• Partly cloudy this evening,  mostly cloudy with a slight (20%) chance of rain and snow late tonight,
• Mostly cloudy with AM rain and snow likely (70%), rain and snow  and a bit cooler Sunday afternoon (0.25 in. of rain possible, 1 in. of snow lower elevations and 2-3 in. of snow above 1,500 ft., snow level 500 ft. rising to 1,500 ft.), evening rain and snow showers, rain and snow showers likely (70%) at night (0.25 in. of rain possible, snow level 1,500 ft. falling to 900 ft. late at night),
• Mostly cloudy with a good (50%) chance of AM rain and snow showers, rain and snow showers likely (70%) Monday afternoon (snow level 600 ft. rising to 1,500 ft. ), cloudy with a (40%) chance of snow showers late Monday night (snow level 1,500 ft. falling to 1,000 ft. late at night),
• Cloudy and a bit warmer with a (30%) chance of rain and snow showers Tuesday, then mostly cloudy with a slight (20%) chance of evening rain and snow showers.
• lows 33-35 cooling to 32 Tuesday night highs 44-48.
• Partly cloudy and a bit warmer Wednesday and Wednesday night,
• Mostly cloudy Thursday and at night,
• Mostly cloudy with a slight (20%) chance of rain and a bit warmer Friday, rain likely (70%) Friday night,
• Then cloudy with a good (50%) chance of rain Saturday.
• highs near 52 lows 36-34 warming to 40 Friday night. (seasonal averages high 55 low 38)

 

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

• Mostly clear this evening at the shore and mostly cloudy with a slight (20%) chance of rain late tonight while partly cloudy inland this evening and mostly cloudy with a slight (20%) chance of inland rain and snow late tonight,
• Cloudy with AM coastal rain and coastal rain with a slight (20%) chance of afternoon thunderstorms while inland rain and snow and a bit cooler Sunday afternoon (0.50 in. of rain possible, snow level 1,000 ft. rising to 1,500 ft. in the afternoon), coastal showers with a slight (20%) of thunderstorms at night while inland rain and snow showers Sunday night (0.25 in. of rain possible, snow 1,500 ft.),
• Mostly cloudy with coastal showers likely (70%) Monday while inland rain and snow showers and a bit warmer, cloudy with evening coastal showers and showers likely (70%) late at night while a good (50%) chance of inland rain and snow showers Monday night,
• Cloudy with a good (50%) chance of AM rain and snow showers, a (40%) chance of showers and a bit warmer Tuesday afternoon, then mostly cloudy with a slight (20%) chance of showers Tuesday night.
• lows 38-42 cooling to 40 Tuesday night highs 46-49.
• Partly cloudy and a bit warmer Wednesday and Wednesday night,
• Mostly cloudy and a bit warmer Thursday and at night,
• Mostly cloudy and a bit warmer with a good (50%) chance of rain Friday, rain likely (70%) Friday night,
• Then cloudy and a bit cooler with a good (50%) chance of rain Saturday.
• highs near 52 lows 40-43. (seasonal averages high 53 low 41)

 

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Forecast for the Cascades in Lane County:

• Partly cloudy this evening, mostly cloudy with a good (50%) chance of snow late tonight,
• Mostly cloudy with AM snow, a bit cooler with snow showers Sunday afternoon (3-7 in. of snow possible) snow showers at night (1-3 in. of snow possible),
• A bit warmer with snow showers likely (70%) Monday and Monday night,
• Mostly cloudy with a AM snow showers likely (70%), good (50%) chance of snow showers and a bit warmer Tuesday afternoon, then a slight (20%) chance of snow showers Tuesday night.
• free air freezing level at the surface this evening, 3,500 ft. late tonight, then snow level at the surface Sunday through Monday night.
• lows near 20-18 highs 28-32.
• Partly cloudy with a slight (20%) chance of snow showers and a bit warmer Wednesday, just partly cloudy Wednesday night through Thursday night,
• Mostly cloudy with a good (50%) chance of rain and snow Friday, rain and snow at night,
• Then mostly cloudy and a bit cooler with a good (50%) chance of rain and snow Saturday.
• snow level 2,500 ft. Wednesday, free air freezing level 4,500 ft. Wednesday night, 5,000 ft. Thursday, 5,500 ft. Thursday night, snow level 4,000 ft. Friday, 4,500 ft. Friday night, then 4,000 ft. Saturday.
• highs 33-36 cooling back to 33 Saturday lows 18-27.

 

 

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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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