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) 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 10 in the Good category measuring Particulate Matter.

Oakridge: The Air Quality Index is 44 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 UNTIL 4 AM MONDAY FOR CENTRAL DOUGLAS COUNTY, EASTERN CURRY COUNTY, JOSEPHINE COUNTY, THE EASTERN DOUGLAS COUNTY FOOTHILLS, JACKSON COUNTY, 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 UNTIL 4 AM MONDAY FOR THE EASTERN DOUGLAS COUNTY FOOTHILLS, 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:

• Mostly cloudy with a good (50%) chance of evening showers, a slight (20%) chance of showers late tonight (0.10 in. of rain possible),
• Mostly cloudy with a good (50%) chance of rain and snow showers Monday AM, showers likely (70%) and a bit warmer in the afternoon (snow level 1,000 ft.), mostly cloudy a good (50%) chance of showers Monday night (0.10 in. of rain possible),
• Mostly cloudy with a good (50%) chance of showers Tuesday (0.10 in. of rain possible), a slight (20%) chance of showers at night,
• Mostly cloudy with a (40%) chance of showers Wednesday, then a slight (20%) chance of showers Wednesday night.
• lows 33-38 highs near 48.
• Mostly cloudy with a (30%) chance of showers Thursday, cloudy with a good (50%) chance of rain at night,
• Mostly cloudy with rain likely (70%) Friday and Friday night,
• Mostly cloudy and a bit cooler with rain Saturday, rain likely (790%) at night,
• Then mostly cloudy with showers likely (70%) Sunday.
• highs near 48 lows 40-38. (seasonal averages high 53 low 36)

 

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Forecast for Roseburg:

• Mostly cloudy with rain and snow showers this evening, a good (50%) chance of rain and snow showers late tonight (0.10 in. of rain possible, 1 in. of snow possible lower elevations and 1-2 in. of snow above 1,500 ft., snow level 1,000 ft.),
• Cloudy with a good (50%) chance of AM rain and snow showers, rain and snow showers likely (70%) and a bit warmer Monday afternoon (0.10 in. of rain possible, snow level 800 ft. rising to 1,500 ft. in the afternoon), cloudy with a (40%) chance of snow showers late Monday night (0.10 in. of rain possible, 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 (snow level 1,000 ft. rising to 2,000 ft. in the afternoon),  mostly cloudy with a slight (20%) chance of showers at night,
• Mostly cloudy and a bit warmer with a slight (20%) chance of showers Wednesday, then just mostly cloudy Wednesday night.
• lows 35-32 warming back to 35 Wednesday night highs 44-52.
• Mostly cloudy and a bit cooler with a slight (20%) chance of rain Thursday and at night,
• Mostly cloudy with a good (50%) chance of rain and a bit warmer Friday and Friday night,
• Cloudy with rain likely (70%) Saturday and at night,
• Then mostly cloudy with rain and snow likely (70%) Sunday.
• highs 52-50 lows 36-42 cooling back to 36 Saturday night. (seasonal averages high 56 low 38)

 

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

• Cloudy with coastal evening showers and a slight (20%) of thunderstorms with a good (50%) chance of showers late tonight while inland evening rain and snow showers with inland rain and snow showers likely (70%) late tonight (0.25 in. of rain possible, no snow accumulation expected, snow level 1,500 ft.),
• Mostly cloudy with coastal showers likely (70%) Monday while inland rain and snow showers likely (70%) and a bit warmer (0.10 in. of rain possible), cloudy with evening coastal showers  likely (70%) and coastal showers late at night while a good (50%) chance of inland evening rain and snow showers with inland showers late Monday night (0.10 in. of rain possible),
• Cloudy with a good (50%) chance of showers and a bit warmer Tuesday (0.10 in. of rain possible, snow level 2,000 ft.), mostly cloudy with a slight (20%) chance of showers Tuesday night,
• Mostly cloudy and a bit warmer with a slight (20%) chance of showers Wednesday, then just mostly cloudy Wednesday night.
• lows 39-42 cooling to 40 Wednesday night highs 47-52.
• Mostly cloudy with a slight (20%) chance of showers Thursday and at night,
• Mostly cloudy and a bit warmer with rain likely (70%) Friday through Saturday night,
• Then cloudy and a bit warmer with rain and snow likely (70%) Sunday.
• highs 52-50 warming back to 52 Sunday lows 45-42. (seasonal averages high 53 low 41)

 

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Forecast for the Cascades in Lane County:

• Mostly cloudy snow showers likely (70%) tonight (2-4 in. of snow possible),
• Mostly cloudy with a good (50%) chance of AM rain and snow showers, a bit warmer with snow showers Monday afternoon (1-3 in. of snow possible) and Monday night (2-3 in. of snow possible),
• Mostly cloudy snow showers likely (70%) and a bit warmer Tuesday, a good (50%) chance of evening snow showers,  a slight (20%) chance of snow showers late Tuesday night,
• A mix of clouds and sun with a good (50%) chance of snow showers and a bit warmer Wednesday, then partly cloudy with a slight (20%) chance of snow showers Wednesday night.
• snow level at the surface tonight through Tuesday, 2,500 ft. Tuesday night and Wednesday, then 3,500 ft. Wednesday night.
• lows near 20-22 cooling to 20 Wednesday night highs 28-35.
• A mix of clouds and sun and a bit warmer with a slight (20%) chance of snow Thursday, mostly cloudy with a slight (20%) chance of snow at night,
• Cloudy and a bit warmer with a good (50%) chance of rain and snow Friday, rain and snow likely (70%) Friday night and Saturday (a bit cooler), rain and snow Saturday night,
• Then mostly cloudy and a bit cooler snow showers likely (70%) Sunday.
• snow level 3,000 ft. Thursday, 4,000 ft. Thursday night through Friday night, 3,000 ft. Saturday, 3,500 ft. Saturday night, then at the surface Sunday.
• highs 36-32 lows 24-27.

 

 

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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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