Aug
13.
An Upper Level High Pressure Ridge (“Arch “Shape) weakens and will be replaced by an Upper Level Low Pressure Trough (“U” shape). The graphics for days 1-3 show a cold frontal system moving through the Pacific Northwest Friday. The graphics for days 3-7 Sunday through Thursday show a cold front moves through Sunday and then another cold front falls apart as it pushes through Wednesday.
ADVISORIES:
- NONE AT THIS TIME.
HEALTH ADVISORIES:
- A PERMANENT HEALTH ADVISORY REMAINS IN EFFECT FOR THE SOUTH UMPQUA RIVER 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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Air Quality Index:
Eugene/Springfield: The Air Quality Index is 12 in the Good category measuring Particulate Matter.
Oakridge: The Air Quality Index is 13 in the Good category measuring Particulate Matter.
Cottage Grove: The Air Quality Index is 12 in the Good category measuring Particulate Matter.
Data courtesy of Lane Regional Air Protection Agency (LRAPA.org)
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Eugene-Springfield Area Pollen count:
GRASS: 0 ABSENT
TREES: 2 LOW
WEEDS: 0 ABSENT
Measured 8.11.25
Data courtesy of Oregon Allergy Associates.
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Forecast for the Southern and lower Mid Willamette Valley including Eugene-Springfield and Albany-Corvallis:
- Mostly clear this evening, mostly cloudy late tonight,
- AM clouds and sun, sunny and cooler Thursday afternoon, partly cloudy in the evening, mostly cloudy with a slight (20%) chance of rain late Thursday night,
- Mostly cloudy and a bit cooler with a good (50%) chance of rain Friday, a (60%) chance of evening rain, mostly cloudy with rain likely (70%) late at night,
- Mostly cloudy with rain likely (70%) Saturday, then a slight (20%) rain Saturday night.
- lows 59-63 cooling to 56 Saturday night highs 83-79.
- AM clouds with with a slight (20%) chance of rain, mostly sunny and a bit warmer with a slight (20%) chance of rain Sunday afternoon, partly cloudy Sunday night,
- Mostly sunny Monday, partly cloudy in the evening, mostly clear at night,
- Then sunny and a bit warmer Tuesday and Wednesday, mostly clear Tuesday night.
- highs 82-85 lows 54-53. (seasonal averages high 85 low 52).
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Forecast for the Umpqua Valley including Roseburg:
- Mostly clear this evening, becoming mostly cloudy late tonight,
- AM clouds with patchy fog, sunny Thursday afternoon, mostly clear in the evening, partly cloudy late Thursday night,
- Mostly cloudy and a bit cooler with a slight (20%) chance of showers Friday, mostly cloudy with a (40%) of evening showers, showers likely (70%) late at night,
- Mostly cloudy with AM showers likely (70%), a bit cooler with a (0%) chance of showers and a slight (20% ) chance of thunderstorms Saturday afternoon, mostly cloudy with a slight (20%) chance of evening thunderstorms, mostly cloudy with a slight (20%) of showers late Saturday night,
- lows 63-67 highs 93-84.
- Mostly cloudy cloudy and a bit warmer with a slight (20%) chance of showers Sunday, just partly cloudy Sunday night,
- Partly cloudy and a bit cooler Monday, mostly clear at night,
- Then mostly sunny and a bit warmer Tuesday and Wednesday, mostly clear Tuesday night.
- highs near 82-86 cooling to 85 Monday warning to 86 Tuesday lows 63-57 (seasonal averages high 86 low 58).
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Forecast for The South Oregon Coast Including Coos Bay and North Bend:
- Mostly cloudy with patchy coastal fog tonight while mostly cloudy with patchy inland fog late tonight,
- Mostly cloudy with areas of AM coastal fog while patchy inland AM fog, sunny Thursday afternoon, mostly cloudy in the evening, a slight (20%) chance of coastal showers mostly cloudy with patchy fog and a slight (20%) chance of showers late Thursday night,
- Patchy AM fog, mostly cloudy with a slight (20%) chance of showers Friday afternoon, cloudy with evening coastal showers likely (70%) late Friday night while a good (50%) chance of evening showers and inland showers likely (70%) late Friday night,
- Mostly cloudy with AM showers likely (70%), a bit cooler with a good (50%) chance showers Saturday afternoon, then mostly cloudy a slight (20%) chance of showers late Saturday night.
- lows 58-62 highs 74-75 cooling to 73 Saturday.
- Mostly cloudy with a slight (20%) chance of AM showers, just partly cloudy and a bit warmer Sunday afternoon, partly cloudy Sunday night,
- Partly cloudy Monday and Monday night,
- Then mostly sunny Tuesday and Wednesday, mostly clear Tuesday night.
- highs 73-75 lows 57-54.
- (seasonal averages high 67 low 54). _______________
Forecast for the Northern Oregon Cascades including the Cascades in Lane County:
- Mostly clear this evening, partly cloudy late tonight,
- Mostly sunny and a bit cooler Thursday, partly cloudy Thursday night,
- AM clouds and sun with a slight (20%) chance of rain, a (30%) chance of rain Friday afternoon, mostly cloudy with rain likely (70%) at night,
- Mostly cloudy with rain and a slight (20%) chance of thunderstorms Saturday, mostly cloudy with a good (50%) chance of rain Saturday night.
- free air freezing level 15,000 ft. tonight, 14,000 ft. Thursday and Thursday night, then snow level above 8,000 ft. Friday through Saturday night.
- lows 47-52 cooling to 49 Saturday night highs 70-63.
- AM clouds with a slight (20%) chance of AM rain, partly cloudy and a bit warmer with a slight (20%) chance of rain Sunday afternoon, ,just partly cloudy Sunday night,
- Mostly sunny and bit warmer Monday, partly cloudy in the evening, mostly clear late at night,
- Then sunny and a bit warmer Tuesday and Wednesday, mostly clear Tuesday night.
- snow level above 8,000 ft. Sunday, free air freezing level 12,000 ft Sunday night, 13,000 ft. Monday and Monday night, then 14,000 ft. Tuesday through Wednesday.
- highs 66-73 lows 49-47.
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