Here is my weekly weather quiz question. What is a “Baroclinic leaf shield?” 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.

________________

 

Southwest airflow from the Jet Stream (Shaded “Arch” shape with blue arrows aimed Southwest to Northeast) will keep warm air headed our way. The graphics for days 1-3 show a weak frontal system moving through Oregon late tonight. The graphics for days 3-7 show the frontal system that attempt to move into the Pacific Northwest Monday.

________________

 

Air Quality Index:

Eugene-Springfield: The Air Quality Index is 38 in the Good category measuring Ozone.

Oakridge: The Air Quality Index is 14 in the Good category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 40 in the Good category measuring Ozone.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

 

__________________

Advisories:

•  The Oregon Health Authority has updated the health advisory issued June 30 for Lake Billy Chinook, located about 12 miles west of Madras in Jefferson County. The update lifts the advisory on those areas of the Deschutes and Crooked River of Lake Billy Chinook arms affected by the advisory, and confines the advisory on the Metolius Arm to Perry South Cove. Water monitoring has confirmed that the level of blue-green algae toxins are below guideline values for human exposure. However, OHA recommends that people remain cautious when using the lake, particularly with pets because toxins are still well above the very low exposure levels established for dogs.
• 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.

________________

 

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

• Mostly clear tonight,
• Sunny and a bit cooler Wednesday, partly cloudy Wednesday night through Thursday night,
• A mix of clouds and sun Friday AM, mostly sunny and a bit warmer in the afternoon, then mostly clear Friday night.
• lows 50-55 cooling to 52 Thursday night and Friday night highs 80-83
• Mostly sunny and a bit warmer Saturday, Sunday, and Monday, mostly clear each night,
• Then sunny and a bit cooler Tuesday.
• highs 86-83 lows 56-52. (seasonal averages high 83 low 52)

_____

Eugene-Springfield Pollen Count

Grass………. High (22)

Trees………. Low (7)

Last Counted: 7/18/17

Data Courtesy of Oregon Allergy Associates.

Note: It would seem the pollen season just about over.

 

________________

 

Forecast for Roseburg:

• Clear tonight,
• Partly cloudy in the AM, sunny and a bit cooler Wednesday afternoon, clear in the evening, mostly cloudy with patchy fog late Wednesday night and Thursday AM, a slight (20%) chance of AM showers, partly cloudy and a bit cooler Thursday afternoon and evening, mostly clear Thursday night,
• Mostly sunny and a bit warmer Friday, then mostly clear at night.
• lows 53-55 highs 83-80 warming to 86 Friday.
• Mostly sunny and a bit warmer Saturday, mostly lear at night,
• Sunny Sunday, clear Sunday night,
• Sunny and a bit cooler Monday and Tuesday, clear at night.
• highs 90-86 lows near 58. (seasonal averages high 85 low 57)

 

_____________________

 

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

• Clear this evening, mostly cloudy with patchy coastal fog and drizzle late tonight,
• Mostly cloudy Wednesday AM, sunny in the afternoon, mostly cloudy with patchy drizzle late Wednesday night and patchy inland fog late at night,
• Mostly cloudy with patchy AM drizzle, partly cloudy Thursday afternoon mostly clear in the evening, partly cloudy late Thursday night,
• Then mostly sunny Friday and mostly clear at night.
• lows near 54 highs near 63.
• Mostly sunny Saturday and Sunday, mostly clear both nights,
• Sunny Monday, mostly clear at night,
• Then mostly sunny Tuesday.
• highs 65-63 warming to 65 Tuesday lows near 54. (seasonal averages high 65 low 53)

 

________________

 

Forecast for the Cascades in Lane County:

• Mostly clear tonight,
• Sunny and a bit cooler Wednesday, mostly clear at night,
• AM clouds and sun, mostly sunny and a bit cooler Thursday afternoon, clear in the evening, partly cloudy late Thursday night,
• Mostly sunny and a bit warmer Friday, then mostly clear at night.
• free air freezing level above 12,000 ft. tonight and Wednesday, above 12,000 ft falling to 12,000 ft. Wednesday night, then above 12,000 ft. Thursday through Friday night,
• lows 44-46 highs 72-67 warming to 73 Friday.
• Mostly sunny and a bit warmer Saturday and Sunday, mostly clear both nights,
• Then sunny and a bit cooler Monday and Tuesday, clear Monday night.
• free air freezing level above 12,000 ft. Saturday through Tuesday,
• highs 78-75 lows 48-50 cooling back to 48 Monday night.

 

________________

**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.

________________

Get your local Eugene-Springfield and Lane County news on-line at eugenedailynews.com.

________________