Here is my weekly weather quiz question. What is “Latent Heat Flux?” 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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A large upper level low (Shaded U shape with blue arrows) continues to send frontal systems at us. A weak frontal system moved into the Pacific Northwest and now the low moves to the northeast bringing us cooler temperatures and more rain. A parade of increasingly  stronger storms like this frontal system that will slide into Oregon Sunday. We will see more frontal systems like this one shown pushing onto the coast next Thursday. Willamette Pass, Hoodoo and Mt. Ashland are all open with great ski conditions. Check their websites for updates.

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Air Quality Index:

Eugene-Springfield: The Air Quality Index is 15 in the Good category measuring Particulate Matter.

Oakridge: The Air Quality Index is 21 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 23 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 UNTIL 4 AM FRIDAY FOR THE NORTHERN OREGON CASCADES AND  THE CASCADES IN LANE COUNTY.
• A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 4 AM FRIDAY FOR THE EASTERN DOUGLAS COUNTY FOOTHILLS,  THE SOUTH CENTRAL OREGON CASCADES, THE SOUTHERN OREGON CASCADES, THE SISKIYOU MOUNTAINS, THE KLAMATH BASIN, THE KLAMATH BASIN, NORTHERN AND EASTERN KLAMATH COUNTY, AND WESTERN, CENTRAL, AND EASTERN LAKE COUNTY.
• A WIND ADVISORY IS IN EFFECT UNTIL 10 PM TONIGHT FOR JACKSON COUNTY.
• A HIGH SURF ADVISORY IS IN EFFECT UNTIL 7 PM TONIGHT FOR THE SOUTH CENTRAL OREGON COAST AND THE CURRY COUNTY COAST.

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Forecast for the Southern and lower Mid Willamette Valley including Eugene-Springfield and Albany-Corvallis:

• Mostly cloudy with rain this evening, showers late tonight (0.25 in. of rain possible),
• Cloudy with a good (50%) chance of showers Friday AM, a mix of clouds and sun and a bit warmer with a slight (20%) chance of showers in the afternoon (under 0.10 in. of rain possible), rain late Friday night (0.25 in. of rain possible) and Saturday, a good (50%) chance of evening showers, cloudy with showers likely (70%) late Saturday night,
• Then mostly cloudy and a bit cooler with rain likely (70%) Sunday and Sunday night.
• lows 40-42 highs 48-52 cooling back to 48 Sunday.
• Mostly cloudy with a good (50%) chance  of rain Monday (Martin Luther King, Jr. Day) and Monday night,
• Rain likely (70%) Tuesday, showers likely (60%) at night,
• Mostly cloudy with a (30%) chance of showers Wednesday, a good (50%) chance of rain Wednesday night,
• Then rain likely (60%) and a bit warmer Thursday.
• highs 48-46 warming back to 48 Thursday lows near 38. (seasonal averages high 47 low 34)

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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.

Advisory Courtesy of Lane Regional Air Protection Agency (LRAPA).

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Forecast for Roseburg:

• Mostly cloudy with rain this evening, a good (50%) chance of showers late tonight (0.15 in. of rain possible, snow level 3,500 ft. falling to 3,000 ft. late at night),
• Areas of AM fog, mostly cloudy and a bit warmer with a slight (20%) chance showers of Friday (0.15 in. of rain possible, AM snow level 3,000 ft.), rain likely (70%) in the evening, rain late Friday night and Saturday, a slight (20%) chance of showers in the evening, showers likely (70%) late Saturday night,
• Then mostly cloudy with rain Sunday and Sunday night.
• lows 39-45 cooling to 40 Sunday night highs 50-52.
• Mostly cloudy and a bit cooler with a (40%) chance of rain Monday (Martin Luther King, Jr. Day) and Monday night,
• Rain likely (70%) Tuesday, a (40%) chance of showers at night,
• Mostly cloudy with a slight (20%) chance of showers Wednesday AM, a slight (20%) chance of afternoon showers, cloudy with a slight (20%) chance of rain Wednesday night,
• Then rain likely (70%) Thursday.
• highs 52-49 lows 42-39. (seasonal averages high 50 low 37)

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Forecast for the South Oregon Coast including Coos Bay and North Bend:

• Mostly cloudy with rain this evening and a slight (20%) chance of early evening thunderstorms (0.45 in. of rain possible), a good (50%) chance of showers late tonight (0.30 in. of rain possible),
• Mostly cloudy and a bit warmer with a slight (20%) chance of showers Friday (under 0.10 in. of rain possible), rain Friday night (0.30 in. of rain possible) and breezy (Wind: S 10-15 mph increasing to S 15-25 mph late evening and at night,
• Mostly cloudy with rain Saturday and breezy (Wind: SW 20-30 mph at the shore while SW 15-20 mph inland, AM gusts to 40 mph), a slight (20%) chance of evening showers, showers late Saturday night and breezy (Wind: S 15-25 mph at the shore while S 10-15 mph late at night).,
• Mostly cloudy with rain Sunday, then rain likely (60%) Sunday night.
• lows 48-46 highs near 54
• Mostly cloudy and a bit cooler with a (40%) chance of rain Monday (Martin Luther King, Jr. Day), cloudy with a good (50%) chance of rain Monday night.
• Rain likely (70%) Tuesday, a good (50%) chance of showers at night,
• Mostly cloudy with a slight (20%) chance of showers Wednesday AM, a slight (20%) chance of rain in the afternoon, cloudy with a (40%) chance of rain at night,
• Then rain likely (70%) Thursday.
• highs near 52 lows 45-42 warming back to 45 Wednesday  night. (seasonal averages high 52 low 40).

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Forecast for the Cascades in Lane County:

• Mostly cloudy with rain this evening, showers late tonight (0.50 in. of rain possible, 4-7 in. of snow possible),
• Mostly cloudy with a good (50%) chance of rain and snow showers Friday AM, a slight (20%) chance of showers and a bit warmer in the afternoon (0.10 in. of rain possible), rain and snow late Friday night (0.50 in. of rain possible, 2 in. of snow possible),
• Cloudy and a bit warmer with rain Saturday and breezy (Wind: SW 15-25 mph gusts to 40 mph), a good (50%) chance of evening showers, rain and snow showers likely (70%) late Saturday night,
• Then rain Sunday and at night.
• snow level 3,500 ft. tonight and Friday, 4,500 ft. rising to 6,000 ft. Friday night, 6,500 ft. falling to 5,500 ft. Saturday, 5,000 ft. Saturday night, 5,500 ft. Sunday, then  5,000 ft. Sunday night.
• lows 26-30 cooling back to 26 Sunday night highs 33-37.
• Mostly cloudy and a bit cooler with a good (50%) chance of rain and snow Monday (Martin Luther King, Jr. Day) and Monday night,
• Rain likely (60%) and a bit cooler Tuesday, showers likely (60%) Tuesday night,
• A mix of clouds and sun and a bit warmer with a slight (20%) chance of rain and snow showers Wednesday, a good (50%) chance of rain and snow at night,
• Then rain likely (60%) Thursday.
• snow level 5,500 ft. Monday, 4,500 ft. Monday night, 4,000 ft. Tuesday, 3,500 ft. Tuesday night,  3,000 ft. Wednesday, then 5,000 ft. Wednesday night and Thursday.
• highs 34-30 warming to 33 Wednesday and Thursday 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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