TIM CHUEY WEATHER

April 27, 2024

Note: Weather is a constantly changing phenomenon and weather forecasting is a combination of science, experience, and intuition. The accuracy of any given forecast can chance due to unexpected changes in atmospheric conditions, so there are no guarantees the the actual weather will conform to the projected forecast.

(NOTE: I won’t be able to publish my forecasts starting April 30th Due to shoulder surgery. I’ll resume as soon as possible.).

ADVISORIES

• A WINTER WEATHER ADVISORY IS IN EFFECT FROM 11 PM SUNDAY UNTIL 11 AM MONDAY FOR THE NORTH OREGON CASCADES, THE CASCADES ON MARION AND LINN COUNTIES, AND THE CASCADES OF LANE COUNTY.
• A WINTER WEATHER ADVISORY IS IN EFFECT FROM 11 PM SUNDAY UNTIL 11 AM MONDAY ABOVE 4,000 FT. THE EAST SLOPES OF THE OREGON CASCADES.FOR
• A FLOOD WARNING IS IN EFFECT UNTIL WEDNESDAY MORNING FOR THE OWYHEE RIVER BELOW THE OWYHEE DAM AFFECTING MALHEUR COUNTY.

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.

THE WEATHER PATTERN:

An Upper Level Low Pressure Trough (“U” shape) sitting right over the Pacific Northwest. The graphics for days 1-3  show a frontal system sliding into the Pacific Northwest today. The graphics for days 3-7    Tuesday through Saturday show the frontal system moving across the Pacific Northwest Tuesday, then another front offshore that pushes in between Thursday and Friday. A frontal system will be poised offshore next Saturday.

Forecast For The South Willamette Valley Including Eugene-Springfield:

• Mostly cloudy with evening rain likely (70%), a good (50%) chance of showers late tonight (under 0.10 in. of rain possible),
• Mostly cloudy with a good (50%) chance of AM showers, partly cloudy and a bit warmer with a good (50%) chance of showers Sunday afternoon (under 0.10 in. of rain possible), showers Sunday night (0.10 in. of rain possible),
• Mostly cloudy and a bit cooler with showers Monday (0.10 in. of rain possible), a good (50%) chance of evening showers, showers likely (70%) late Monday night (under 0.10 in. of rain possible),
• Mostly cloudy with showers likely (70%) and a slight (20%) chance of thunderstorms Tuesday, then partly cloudy with a slight (20%) chance of showers Tuesday night.
• lows 47-38 highs 58-56.
• Mostly sunny and a bit warmer Wednesday, partly cloudy with a (40%) chance of evening showers, a (40%) chance of showers late Wednesday night,
• A mix of clouds and sun and a bit warmer with a (40%) chance of showers Thursday, partly cloudy with a slight (20%) chance of showers at night,
• Mostly sunny and a bit warmer Friday, partly cloudy with a slight (20%) chance of showers Friday night,
• Then a mix of clouds and sun and as bit cooler with a (40%) chance of showers Saturday.
• highs 63-68 cooling to 65 Saturday lows 40-44 (seasonal averages high 64 low 42)

Forecast for the Umpqua Valley including Roseburg:

• Mostly cloudy with a (40%) chance of showers tonight (under 0.10 in. of rain possible),
• Mostly cloudy and a bit warmer with a (30%) chance of showers Sunday snow level 3,500 ft), a (30%) of showers Sunday night (under 0.10 in. of rain possible, snow level 3,500 ft. falling to 3,300 ft. late at night),
• Mostly cloudy with AM showers, a good (50%) chance of showers and a bit cooler Monday afternoon (under o.10 in. of rain possible, snow level 3,000 ft.), a (30%) of evening showers, a (30%) chance of rain and snow showers late at night (snow level 3,000 ft. falling to 2,500 ft. late at night),
• Mostly cloudy with a (30%) chance of AM rain and snow showers, a bit warmer with a (40%) chance of showers Tuesday afternoon, then partly cloudy with areas of frost late Tuesday night.
• lows 44-47 cooling to 42 Sunday night highs 62-57 warming to 59 Saturday.
• Some AM clouds with patchy frost, sunny and a bit warmer Wednesday afternoon, partly cloudy with a slight (20%) chance of evening showers, mostly cloudy with a slight (20%) chance of showers Wednesday night,
• Mostly cloudy and a bit warmer with a (30%) chance of showers Thursday, partly cloudy with a slight (20%) chance of evening showers, just partly cloudy late at night,
• Some AM clouds, sunny and a bit warmer Friday afternoon, partly cloudy with a slight (20%) chance of rain late Friday night,
• Then mostly cloudy and a bit cooler with a slight (20%) chance of rain Saturday.
• highs 66-72 cooling to 68 Saturday lows 40-44. (seasonal average high 66 low 44)

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

• Mostly cloudy with early evening coastal showers likely (70%) and a (40%) chance of late evening coastal showers continuing through tonight while a (40%) chance of inland showers tonight (under 0.10 in. of rain possible),
• Mostly cloudy with a (40%) chance of showers Sunday (under 0.10 in. of rain possible), a slight (20%) chance of evening coastal showers and coastal showers likely (70%) late Sunday night while a good (50%) chance of inland showers Sunday night (0.10 in. of rain possible),
• Mostly cloudy with AM showers likely (70%), a bit warmer with a good (50%) chance of showers Monday afternoon (under 0.10 in. of rain possible), partly cloudy with a (40%) of evening showers, mostly cloudy with a (40%) chance of showers late at night (under 0.10 in. of rain possible),
• Mostly sunny and a bit warmer with a good  (50%) chance of showers Tuesday, then just partly cloudy Tuesday night.
• lows 45-40 highs near 56.
• Some AM clouds, sunny and a bit cooler Wednesday afternoon, partly cloudy with a (30%) chance of showers Wednesday night,
• Partly cloudy and a bit cooler with a (30%) chance of showers Thursday, partly cloudy with a slight (20%) chance of evening showers, just partly cloudy late at night,
• Partly cloudy and a bit warmer Friday, partly cloudy with a slight (20%) chance of evening rain, mostly cloudy with a slight (20%) chance of rain late Friday night,
• Then mostly cloudy and a bit cooler with a (30%) chance of rain Saturday.
• highs 60-62 cooling back 60 Saturday lows 42-44. (seasonal average high 58 low 45)

Forecast for the Northern Oregon Cascades including Willamette Pass:

• Mostly cloudy with evening rain, a good (50%) chance of showers late tonight (0.25 in. of rain possible),
• Mostly cloudy and a bit warmer with a good (50%) chance of rain and snow showers Sunday (0.10 in. of rain possible, little or no snow accumulation expected), rain and snow showers Sunday night (0.50 in. of rain possible, 1 in. of snow possible),
• Mostly cloudy and a bit cooler with snow and rain showers Monday (AM snow possibly heavy at times), rain and snow showers Monday night,
• Mostly cloudy and a bit warmer with snow and rain showers likely (70%) Tuesday, then a good (50%) chance of rain and snow showers with a slight (20%) chance of thunderstorms Tuesday night.
• snow level 5,000 ft. tonight, 4,500 ft. Sunday, 3,500 ft. Sunday night, 3,000 ft. Monday, 2,500 ft. Monday night, 3,000 ft. Tuesday, then 3,500 ft. Tuesday night,
• lows 34-24 highs 46-37 warming to 48 Tuesday.
• Mostly sunny and a bit warmer with a slight (20%) chance of rain and snow showers Wednesday, mostly cloudy with a (40%) chance of evening rain showers and a slight (20%) chance of snow showers, mostly cloudy with a (40%) chance of rain and snow showers late Wednesday night,
• A mix of clouds and sun with a (40%) chance of rain and snow showers and a bit warmer Thursday, mostly cloudy with a (40%) chance of evening rain and snow showers, partly cloudy with a (40%) chance of  rain showers and a slight (20%) chance of snow showers late at night,
• Mostly sunny and a bit warmer with a (30%) chance of snow showers and a slight (20%) chance of rain showers Friday, partly cloudy with a slight (20%) chance of showers Friday night,
• Then a mix of clouds and sun and a bit cooler with a good (50%) chance of rain and snow showers Saturday.
• snow level  4000 ft. Wednesday, 5,000 ft. Wednesday night, 5,500 ft. Thursday, 6,000 ft. Thursday night and Friday, 6,500 Friday night, then 6,000 ft. Saturday.
• highs 48-56 cooling to 52 Saturday lows 29-34.