TIM CHUEY WEATHER

April 25, 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.

ADVISORIES

• A FLOOD WARNING IS IN EFFECT UNTIL  FURTHER NOTICE FOR THE OWYHEE RIVER BELOW THE OWYHEE DAM AFFECTING MALHEUR COUNTY.
• A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL MIDNIGHT FRIDAY NIGHT ABOVE 4,500 FT. FOR THE NORTH OREGON CASCADES, THE CASCADES OF MARION AND LINN COUNTIES, AND THE CASCADES OF LANE COUNTY.
• A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 2 PM FRIDAY ABOVE 5,000 FT. FOR THE SOUTH CENTRAL OREGON CASCADES, THE SISKIYOU MOUNTAINS, AND THE SOUTHERN OREGON CASCADES.

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 High Pressure Ridge (“Arch” shape) is weakening and moving eastward away from us to be replaced by an Upper Level Low Pressure Trough.  The graphics for days 1-3  show a complex frontal system sliding into the Pacific Northwest tonight into Friday. The graphics for days 3-7    Sunday through Thursday show the frontal system moving across the Pacific Northwest between Sunday and Monday and then another front offshore that pushes in next Thursday.

Forecast For The South Willamette Valley Including Eugene-Springfield:

• Mostly cloudy with showers tonight (0.50 in. of rain possible),
• Mostly cloudy with showers and a bit cooler Friday (0.50 in. of rain possible),a good (50%) chance of evening showers, a (30%) chance of showers late Friday night,
• Mostly cloudy with a slight (20%) chance of AM showers, showers likely (70%) and a bit warmer Saturday afternoon and evening, a good (50%) chance of rain late at night,
• Mostly cloudy with showers likely (70%) and a bit warmer Sunday, then a good (50%) chance of showers Sunday night.
• lows 48-43 warming to 47 Saturday night highs 56-59.
• A mix of clouds and sun and a bit cooler with a good (50%) chance of showers Monday, partly cloudy with a slight (20%) chance of showers Monday night,
• Mostly sunny and a bit warmer with a slight (20%) chance of showers Tuesday, partly cloudy with a slight (20%) chance of evening showers, mostly cloudy with a slight (20%) chance of showers late at night,
• A mix of clouds and sun with a good (50%) chance of AM showers, mostly cloudy with a good (50%) chance of showers Wednesday afternoon and Wednesday night,
• AM clouds and sun with a good (50%) chance of showers, then mostly cloudy with a good (50%) chance of showers Thursday afternoon.
• highs 62-59 warming back t0 62 Tuesday and Wednesday lows 44-39 (seasonal averages high 64 low 41)

Forecast for the Umpqua Valley including Roseburg:

• Mostly cloudy with rain tonight (0.10 in. of rain possible),
• Mostly cloudy with rain Friday (0.25 in. of rain possible) and in the evening, a slight (20%) chance of rain late Friday night (under 0.10 in. of rain possible),
• Mostly cloudy with a slight (20%) chance of AM rain, rain likely (70%) and a bit cooler Saturday afternoon, evening rain likely (70%), a good (50%) chance of rain late at night,
• Mostly cloudy with a good (50%) chance of AM rain, showers likely (70%) and a bit warmer Sunday afternoon, then mostly cloudy with a (30%) chance of showers Sunday night.
• lows 46-43 warming back to 46 Saturday night cooling to 44 Sunday night highs 56-62.
• Mostly cloudy with a (30%) chance of AM rain and snow showers, a (30%) chance of showers Monday afternoon, partly cloudy with a slight (20%) chance of showers Monday  night,
• Partly cloudy and a bit warmer with a slight (20%) chance of showers Tuesday and at night,
• Mostly cloudy and a bit cooler with a (30%) chance of showers Wednesday, a (40%) chance of showers Wednesday night,
• Mostly cloudy with a good (50%) chance of AM showers, then showers likely (70%) Thursday afternoon.
• highs 62-69 cooling back to 62 Thursday lows 39-45. (seasonal averages high 66 low 44)

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

• Mostly cloudy with evening coastal rain and coastal rain likely (70%) late tonight (0.25 in. of rain possible),
• Mostly cloudy with AM rain, rain likely (70%) Friday afternoon (0.25 in. of rain possible), a (40%) chance of evening rain, a slight (20%) chance of rain late Friday night,
• Mostly cloudy with a slight (20%) chance of AM rain, rain likely (70%) Saturday afternoon, cloudy with evening rain likely (70%), a good (50%) chance of rain late Saturday night,
• Mostly cloudy with AM rain likely (70%), a good (50%) chance of rain Sunday afternoon, then a (40%) of showers Sunday night.
• lows 48-44 warming to 47 Saturday night cooling to 42 Sunday night highs near 56.
• Mostly cloudy with a (40%) chance of AM showers, partly cloudy and a bit warmer with a (50%) chance of showers Monday afternoon, partly cloudy with a slight (20%) of showers Monday night,
• Partly cloudy and a bit warmer with a slight (20%) chance of showers Tuesday and in the evening, mostly cloudy with a  slight (20%) chance of showers late at night,
• Mostly cloudy and a bit cooler with a (40%) chance of showers Wednesday and Wednesday night,
• Then mostly cloudy and a bit cooler with a good (50%) chance of showers Thursday.
• highs 57-60 cooling back 57 Thursday lows 38-42. (seasonal average high 58 low 45)

Forecast for the Northern Oregon Cascades including Willamette Pass:

• Mostly cloudy with rain and snow showers tonight (1.00 in. of rain possible, 1 in. of snow possible, snow possibly heavy at times),
• Mostly cloudy and a bit cooler with rain and snow showers Friday (0.50 in. of rain possible, 1 in. of snow possible), evening rain and snow showers, snow showers likely (70%) with a good (50%) chance of rain showers late Friday night (0.25 in. of rain possible, little or no snow accu0mulation expected),
• Mostly cloudy with a (40%) chance of AM snow showers and a slight (20%) chance of rain showers, rain showers with snow showers likely (70%) and a bit warmer with rain and snow showers likely (70%) Saturday afternoon, rain and snow showers Saturday night,
• Mostly cloudy and a bit warmer with rain and snow showers likely (70%) Sunday, then rain and snow showers likely (70%) Sunday night.
• snow level 5,000 ft. tonight, 4,500 ft. Friday, 4,000 ft. Friday night, 4,000 ft. rising to 5,000 ft. Saturday afternoon, 5,500 ft. Saturday night, 5,000 ft. Sunday, then 4,000 ft. Sunday night.
• lows 34-32 warming back to 34 Saturday night cooling to 30 Sunday night highs 39-46.
• Mostly cloudy with a good (50%) chance of AM rain and snow showers, partly cloudy and a bit cooler with a good (50%) chance of rain and snow showers Monday afternoon, mostly cloudy with slight (20%) chance of evening rain and snow showers, partly cloudy with a slight (20%) chance of  rain and snow showers late Monday night,
• Mostly sunny and warmer with a (30%) chance of rain and snow showers Tuesday, partly cloudy with a slight (20%) chance of evening rain and snow showers, mostly cloudy with a slight (20%) chance of rain and snow showers at night,
• A mix of clouds and sun and a bit warmer with a good (50%) chance of rain and snow showers Wednesday and Wednesday night,
• Then mostly cloudy and cooler with rain and snow showers likely (70%).
• snow level  3,500 ft. Monday and Monday night, 4,500 ft.  Tuesday, 5,000 ft. Tuesday night, 5.500 ft. Wednesday, 5,000 ft. Wednesday night, then 4,500 ft. Thursday.
• highs 43-55 cooling to 46 Thursday lows 27-34 cooling to 32 Wednesday night.
• highs 45-43 warming to 48 Monday night and Tuesday night lows 32-28 warming back to 32 Tuesday night.