Here is my weekly weather quiz question for the last time. What is an “Air Mass Thunderstorm?” Here is the correct answer. An Air Mass Thunderstorm: Generally, a thunderstorm not associated with a front or other type of synoptic-scale forcing mechanism. Air mass thunderstorms typically are associated with warm, humid air in the summer months; they develop during the afternoon in response to insolation, and dissipate rather quickly after sunset. They generally are less likely to be severe than other types of thunderstorms, but they still are capable of producing downbursts, brief heavy rain, and (in extreme cases) hail over 3/4 inch in diameter. 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. The first person to post the correct answer will win a week of free personalized weather forecasts tailored to your needs.  Good luck.

________________

An Upper Level High Pressure Ridge (Shaded “Arch” shape with blue arrows) keeps the Pacific Northwest dry for another day today. The graphic for days 1-3 shows a disturbance forming that will bring clouds and the chance of precipitation. The graphic for days 3-7 shows a more complex frontal system building up and heading our way. For mountain snow conditions at the local ski areas check out their websites or give them a call.

________________

 

Air Quality Index:

Eugene-Springfield: The Air Quality Index is 76 in the Moderate category measuring Particulate Matter.

Oakridge: The Air Quality Index is 115 in the Unhealthy for Sensitive Groups category measuring Particulate Matter.

Cottage Grove: The Air Quality Index is 69 in the Moderate category measuring Particulate Matter.

Data courtesy of Lane Regional Air Protection Agency (LRAPA)

________________

Home Wood Heating Advisory:

Eugene-Springfield: YELLOW – Caution is Advised.

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)

________________

Advisories:

• AN AIR STAGNATION ADVISORY IS IN EFFECT UNTIL NOON TUESDAY FOR THE CENTRAL WILLAMETTE VALLEY, THE SOUTH WILLAMETTE VALLEY, THE NORTHERN OREGON CASCADE FOOTHILLS, AND THE CASCADE FOOTHILLS IN LANE COUNTY.
• AN AIR STAGNATION ADVISORY IS IN EFFECT UNTIL 1 PM TODAY FOR CENTRAL DOUGLAS COUNTY, EASTERN CURRY COUNTY, JOSEPHINE COUNTY, JACKSON COUNTY, THE KLAMATH BASIN, NORTHERN AND EASTERN KLAMATH COUNTY, AND CENTRAL, EASTERN AND WESTERN LAKE 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.

 

________________

 

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

• Mostly cloudy with areas of fog, possibly dense, this AM, a mix of clouds and sun and a bit warmer this afternoon, mostly cloudy with patchy fog late tonight,
• Patchy AM fog, then mostly cloudy and a bit warmer Monday, a slight (20%) chance of rain late at night,
• Cloudy and a bit warmer with a (40%) chance of rain Tuesday, then a good (50%) chance of rain Tuesday night.
• highs 42-49 lows 33-36.
• Mostly cloudy and bit cooler with a good (50%) chance of rain Wednesday, rain likely (70%) Wednesday night through Friday (a bit warmer), cloudy with a good (50%) chance of rain Friday night,
• Then mostly cloudy with a (30%) chance of showers Saturday.
• highs 47-44 warming back to 47 Friday lows near 35. (seasonal averages high 49 low 35)

 

_____________________

Forecast for Roseburg:

• Partly cloudy with patchy fog this AM, partly cloudy and a bit warmer this afternoon, mostly cloudy with patchy fog and freezing fog late tonight and Monday AM, partly cloudy in the evening, mostly cloudy late at night,
• Mostly cloudy with a slight (20%) chance of rain Tuesday, then mostly cloudy with a (40%) chance of  rain Tuesday night.
• highs near 54 lows 35-38.
• Cloudy and a bit warmer with a (40%) chance of rain Wednesday, rain likely (70%) Wednesday night and Thursday (a bit cooler), rain at night,
• Mostly cloudy with rain likely (70%) Friday, cloudy with a (40%) chance of showers Friday night,
• Then mostly cloudy with a slight (20%) chance of showers Saturday.
• highs 55-52 lows 40-38. (seasonal averages high 51 low 37)

________________

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

• Partly cloudy with patchy fog this AM, mostly cloudy and a bit warmer this afternoon and tonight with patchy fog late,
• Mostly cloudy with patchy AM fog, partly cloudy and a bit warmer Monday afternoon, mostly cloudy at night,
• Cloudy with a slight (20%) chance of rain and a bit cooler Tuesday, then a (40%) of rain Tuesday night.
• highs near 55 lows 38-42.
• Cloudy with a good (50%) chance of rain and a bit warmer Wednesday, rain Wednesday night through Thursday night,
• Mostly cloudy and a bit cooler with rain likely (70%) Friday, a (40%) chance of showers at night,
• Then mostly cloudy with a slight (20%) chance of showers Saturday.
• highs 57-53 lows 44-40. (seasonal averages high 52 low 40)

 

________________

 

Forecast for the Cascades in Lane County:

• Partly cloudy today, mostly cloudy tonight,
• A mix of clouds and sun and a bit warmer Monday, partly cloudy in the evening, mostly cloudy late Monday night,
• Mostly cloudy and colder with a slight (20%) chance of rain and snow Tuesday, then cloudy with a good (50%) chance of rain and snow Tuesday night.
• free air freezing level 9,000 ft. rising to 10,000 ft. this afternoon, 7,500 ft. falling to 7,000 ft. late tonight, 6,500 ft. rising to 8,000 ft. Monday, 7,000 ft. Monday night, snow level 4,500 ft. Tuesday, then 5,000 ft. Tuesday night.
• highs 46-48 cooling to 38 Tuesday lows 29-27.
• Mostly cloudy and a bit cooler with a good (50%) chance of rain and snow Wednesday, rain and snow likely (70%) Wednesday night through Friday night,
• Then a mix of clouds and sun with a (30%) chance of rain and snow showers Saturday.
•  snow level 4,500 ft. Wednesday, 4,500 ft. Wednesday night, 4,000 ft. Thursday, then 4,500 ft. Thursday night through Saturday.
• highs 37-35 warming back to 37 Saturday lows 28-25.

 

 

________________

 

**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.

________________