Here is my weekly weather quiz question for the last time. “What is a “Roll Cloud?” Here is the correct answer. A Roll Cloud is a low, horizontal tube-shaped arcus cloud associated with a thunderstorm gust front (or sometimes with a cold front). Roll clouds are relatively rare; they are completely detached from the thunderstorm base or other cloud features, thus differentiating them from the more familiar shelf clouds. Roll clouds usually appear to be “rolling” about a horizontal axis, but should not be confused with funnel clouds.
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An Upper Level High Pressure Ridge (“Arch” shape) starts heating us up. The graphics for days 1-3 show a frontal system offshore headed to the Pacific Northwest today then pushing through by tonight. The graphics for days 3-7 Tuesday through Saturday show a cold front that will be pushing through the Pacific Northwest Tuesday and Tuesday night. Another front will slide through Oregon Friday and Friday night.
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.
Forecast for the Southern and lower Mid Willamette Valley including Eugene-Springfield and Albany-Corvallis:
- Mostly cloudy tonight,
- Sunny and a bit cooler Sunday, mostly clear Sunday night,
- Sunny Monday, clear at night,
- Sunny Tuesday, then mostly clear Tuesday night.
- lows 52-48 warming to 50 Monday night cooling back to 48 Tuesday night high near 79.
- Sunny and a bit cooler Wednesday, clear Wednesday night,
- Sunny and a bit warmer Thursday, mostly clear at night,
- Mostly sunny and a bit cooler Friday, partly cloudy Friday night,
- Then mostly sunny and a bit warmer with a slight (20%) chance of rain Saturday.
- highs 75-78 cooling to 68 Saturday lows near 47. (seasonal averages high 72 low 47)
Forecast for the Umpqua Valley including Roseburg:
- Mostly cloudy with a slight (20%) chance of early evening thunderstorms, just partly cloudy late tonight,
- Sunny and a bit cooler Sunday, mostly clear in the evening, partly cloudy late Sunday night,
- Sunny and a bit warmer Monday, mostly clear at night,
- Sunny and a bit cooler Tuesday, then mostly clear Tuesday night.
- lows 56-54 warming back to 56 Monday night highs 82-86 cooling to 85 Tuesday.
- Mostly sunny and a bit cooler Wednesday, clear Wednesday night,
- Sunny and a bit warmer Thursday, mostly clear at night,
- Mostly sunny and a bit cooler Friday, partly cloudy Friday night,
- Then partly cloudy and a bit cooler Saturday.
- highs 79-82 cooling to 72 Saturday lows near 50. (seasonal average high 75 low 51)
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Forecast for The South Oregon Coast Including Coos Bay and North Bend:
- Mostly cloudy with a slight (20%) chance of inland early evening, mostly cloudy late tonight,
- Some AM clouds, sunny and a bit cooler Sunday afternoon, partly cloudy in the evening, mostly cloudy Sunday night,
- Some AM clouds, sunny Monday afternoon, mostly clear at night,
- Sunny and a bit warmer Tuesday, then partly cloudy Tuesday night.
- lows near 48 highs 63-67.
- Some AM clouds, sunny and a bit cooler Wednesday afternoon, clear Wednesday night,
- Sunny and a bit cooler Thursday, partly cloudy at night,
- Partly cloudy Friday, partly cloudy Friday night,
- Then partly cloudy and a bit cooler Saturday.
- highs 66-64 lows near 47. (seasonal average high 63 low 51)
Forecast for the Northern Oregon Cascades including the Cascades in Lane County:
- Mostly cloudy with a slight (20%) chance of thunderstorms tonight,
- A slight (20%) chance of AM thunderstorms, mostly sunny and a bit cooler Sunday afternoon, mostly clear Sunday night,
- Sunny and a bit warmer Monday, mostly clear at night,
- Sunny and a bit cooler Tuesday, mostly clear in the evening, then partly cloudy late Tuesday night.
- free air freezing level 14,000 ft. falling to 13,000 ft. late tonight, 12,000 ft. Sunday, 13,000 ft. Sunday night, 14,000 ft. Monday and Monday night, then 14,000 ft. Tuesday and Tuesday night.
- lows 48-43 warming to 46 Monday night cooling to 42 Tuesday night highs 66-70.
- Sunny Wednesday, clear Wednesday night,
- Sunny and a bit warmer Thursday, mostly clear at night,
- Sunny and cooler Friday, partly cloudy in the evening, mostly cloudy late Friday night,
- Then mostly sunny and a bit cooler with a slight (20%) chance of rain Saturday.
- free air freezing level 14,000 ft. Wednesday and Wednesday night, 15,000 ft. Thursday, 14,000 ft. Thursday night, 11,000 ft. Friday, 10,000 ft. Friday night, then snow level 6,500 ft. Saturday.
- highs 68-72 cooling to 59 Saturday lows 43-39.