Here is my weekly weather quiz question for the last time. What is the“Action Stage?” Here is the correct answer. Action Stage is the stage which, when reached by a rising stream, represents the level where the NWS or a partner/user needs to take some type of mitigation action in preparation for possible signif­icant hydrologic activity. The appropriate action is usually defined in a weather forecast office (WFO) hydrologic services manual. Action stage can be the same as forecast issuance stage (see / forecast issuance stage/). I’ll have a new weekly weather quiz question for you starting Monday. Please remember to post your answer at the bottom of this page. An email will not suffice. 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 trough of low pressure (Shaded “U” shape with blue arrows) is temporarily being replaced by high pressure (Shaded “Arch” shape with blue arrows) which brought sunshine and freezing fog to us to make it at least look like a “White Christmas” despite the fact that we didn’t get any snow. Low pressure does return though. The days 1-3 graphic shows the frontal system moving Southeast away from us. The graphic for days 3-7 shows a series of frontal systems that will be keeping us in precipitation Tuesday and again Friday. So far, the snow will stay in the mountains. For mountain snow conditions at the local ski areas check out their websites or give them a call.

Note: Many people always ask me what are the chances of the Eugene-Springfield area having a “White Christmas.” I checked with  the National Weather Service Forecast Office in Portland to confirm a statistic I remember from back in the days when we had a local weather service office at the Eugene Airport. Clinton Rockey, their climatology expert, says that we have no more than a 2% chance of having a White Christmas. That is calculated from the historical climate data going back to when the local office first opened.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 16 in the Good category measuring Particulate Matter.

Oakridge: The Air Quality Index is 50 in the Moderate category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 15 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: YELLOW – Caution is Advised.

*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 STORM WATCH IS IN EFFECT FOR MONDAY NIGHT FOR THE WESTERN COLUMBIA RIVER GORGE AND THE CENTRAL COLUMBIA RIVER GORGE.
• A FROST ADVISORY IS IN EFFECT FROM 10 PM TONIGHT UNTIL 7 AM MONDAY FOR THE SOUTH CENTRAL OREGON COAST AND THE CURRY COUNTY COAST.
• 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 sunny and a bit cooler this afternoon (Christmas Day), partly cloudy with areas of freezing fog late tonight,
• A mix of clouds and sun with patchy AM fog and a bit warmer Monday, increasing clouds with rain at night (0.25 in. of rain possible),
• Mostly cloudy with showers Tuesday and at night,
• highs near 37-47 lows 29-38.
• Mostly cloudy with a (30%) chance of showers Wednesday, a slight (20%) chance of showers at night,
• A mix of clouds and sun and a bit cooler Thursday, partly cloudy at night,
• A mix of clouds and sun with a slight (20%) chance of showers Friday and Saturday, mostly cloudy with a slight (20%) chance of showers.
• highs near 44 lows 34-30 warming back to 34 Friday night. (seasonal averages high 45 low 33)

 

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Forecast for Roseburg:

• Sunny and a bit cooler this afternoon (Christmas Day), mostly clear this evening, partly cloudy with patchy freezing fog late tonight,
• Patchy AM freezing fog, mostly cloudy and a bit warmer Monday afternoon, cloudy with a (40%) chance of evening rain, rain and snow likely (60%) late Monday night (under 0.10 in. of rain possible, snow level 3,000 ft. falling to 2,500 ft.),
• Mostly cloudy with AM rain, showers and a bit warmer Tuesday afternoon, rain likely (70%) Tuesday night.
• highs 42-48 lows 30-39.
• Mostly cloudy with a (30%) chance of showers Wednesday, a slight (20%) chance of showers with areas of fog late Wednesday night,
• Mostly cloudy with areas of AM fog, partly cloudy and a bit cooler Thursday afternoon, areas of fog and freezing fog late Thursday night and Friday AM, partly cloudy with a slight (20%) chance of rain Friday afternoon, a (30%) chance of rain at night,
• Mostly cloudy with a slight (20%) chance of showers Saturday AM, a slight (20%) chance of rain in the afternoon.
• highs near 47 lows near 36. (seasonal averages high 48 low 36)

 

 

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

• Sunny this afternoon (Christmas Day), mostly clear this evening, partly cloudy with patchy inland fog and freezing fog late tonight,
• Mostly cloudy with patchy inland freezing fog Monday AM, just mostly cloudy and a bit warmer in the afternoon, coastal evening rain likely (70%) and rain late Monday night while a good (50%) chance of inland evening rain and inland rain likely (70%) late Monday night (0.25 in. of rain possible),
• Mostly cloudy with AM rain, showers and a bit warmer Tuesday afternoon, then rain likely (60%) Tuesday night.
• highs 47-52 lows 33-44 cooling to 42 Tuesday night.
• Mostly cloudy with a (30%) chance of showers Wednesday, a slight (20%) chance of showers with areas of fog at night,
• Mostly cloudy with areas of AM fog, partly cloudy Thursday afternoon, partly cloudy with areas of fog late Thursday night and Friday AM, partly cloudy with a slight (20%) chance of showers Friday through Saturday AM, then a slight (20%) chance of rain in the afternoon.
• highs 52-50 rising to 52 Saturday lows near 40. (seasonal averages high 51 low 40)

 

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Forecast for the Cascades in Lane County:

• Mostly sunny and a bit warmer this afternoon, partly cloudy and cold tonight,
• Mostly sunny in the AM, more clouds and a bit warmer Monday afternoon, mostly cloudy with snow Monday night (Heavy Snow Expected),
• Mostly cloudy with snow showers and a bit warmer Tuesday (Heavy Snow Expected), snow showers decreasing late at night.
• free air freezing level at the surface today through Monday, snow level at the surface Monday night, 3,500 ft. Tuesday, then 3,000 ft. Tuesday night.
• highs 28-32 lows 15-24.
• Mostly cloudy with a (40%) chance of rain and snow showers and a bit cooler Wednesday, partly cloudy with a slight (20%) chance of rain and snow showers Wednesday night,
• A mix of clouds and sun and a bit warmer Thursday, partly cloudy at night,
• Partly cloudy with a slight (20%) chance of showers Friday, a slight (20%) chance of rain and snow showers Friday night,
• Then a mix of clouds and sun with a slight (20%) chance of rain and snow showers Saturday.
• snow level 3,500 ft. Wednesday, 4,000 ft. Wednesday night, free air freezing level 5,500 ft. Thursday, 7,000 ft. Thursday night, snow level 5,500 ft. Friday, then 4,000 ft. Friday night and Saturday.
• highs 32-35 lows near 24.

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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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