TIM CHUEY WEATHER

April 26, 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 LATE THURSDAY 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 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 Saturday. The graphics for days 3-7    Monday through Friday show the frontal system moving across the Pacific Northwest between Monday and Tuesday, then another front offshore that pushes in next Thursday.

Forecast For The South Willamette Valley Including Eugene-Springfield:

• Mostly cloudy with a good (50%) chance of evening showers, a slight (20%) chance of showers late tonight (0.25 in. of rain possible),
• Mostly cloudy with rain likely (70%) and a bit warmer Saturday (under 0.10 in. of rain possible), evening showers likely (70%), a good (50%) chance of showers late Saturday night (under 0.10 in. of rain possible),
• Mostly cloudy with showers likely (70%) and a bit warmer Sunday (under 0.10 in. of rain possible), a good (50%) chance of evening showers, showers likely (70%) late at night (under 0.10 in. of rain possible),
• Mostly cloudy and a bit cooler with showers likely (70%) Monday, then a good (50%) chance of showers Monday night.
• lows 43-47 cooling to 42 Sunday night highs 57-60 cooling back to 57 Monday.
• A mix of clouds and sun and a bit warmer with a good (50%) chance of showers and a slight (20%) chance of thunderstorms Tuesday, just partly cloudy Tuesday night,
• A mix of clouds and sun and a bit warmer with a slight  (20%) chance of showers Wednesday, mostly cloudy with a (40%) chance of showers at night,
• A mix of clouds and sun with a good (50%) chance of showers Thursday, mostly cloudy with a good (50%) chance of showers Thursday night,
• Then a mix of clouds and sun with a (40%) chance of showers Friday.
• highs 59-65 lows 39-44 (seasonal averages high 64 low 41)

Forecast for the Umpqua Valley including Roseburg:

• Mostly cloudy with showers likely (70%) and a slight (20%) chance of thunderstorms late tonight,
• Mostly cloudy with a good (50%) of rain Saturday afternoon, a slight (20%) chance of rain Saturday night (under 0.10 in. of rain possible),
• Mostly cloudy with a (30%) chance of showers Sunday, a good (50%) of showers at night (snow level 4,400 ft. falling to 3,300 ft. late at night),
• Mostly cloudy and a bit warmer with a good (50%) chance of showers Monday afternoon (snow level 3,000 ft.), then just mostly cloudy with a slight (20%) of showers Monday night (snow level 3,100 ft).
• lows 44-47 cooling to 42 Sunday night highs 54-56.
• Mostly cloudy with a (30%) chance of showers and a bit warmer Tuesday (snow level 2,800 ft. rising to 4,100 ft.), just partly cloudy Tuesday night,
• Mostly sunny and a bit cooler with a slight (20%) chance of showers Wednesday, a (%) chance of showers at night,
• A mix of clouds and sun and a bit cooler with a good (50%) chance of showers Thursday, mostly cloudy with a (40%) chance of showers Thursday night,
• Then a mix of clouds and sun with a (30%) chance of showers Friday.
• highs 56-62 lows 40-44. (seasonal average high 66 low 44)

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

• Mostly cloudy with a (40%) chance of evening rain, a slight (20%) of rain late tonight (0.10 in. of rain possible),
• Mostly cloudy with rain likely (70%) Saturday afternoon, cloudy with a good (50%) chance of rain Saturday night,
• Mostly cloudy with a good (50%) chance of AM rain, a slight (20%) chance of rain Sunday afternoon, showers likely (70%) Sunday night (snow level 3,300 ft.),
• Clouds and sun with AM showers showers likely (70%), a mix of clouds and sun and a bit warmer Monday afternoon, then partly cloudy with a (30%) of showers late Monday night (snow level 3,300 ft.).
• lows 48-44 warming to 47 Saturday night cooling to 42 Sunday night highs near 56.
• AM sun with a slight (20%) chance of showers, mostly sunny and a bit warmer Tuesday afternoon, just partly cloudy Tuesday night,
• A mix of clouds and sun and a bit cooler with a (40%) chance of showers Wednesday afternoon, mostly cloudy with a slight (20%) chance of showers at night,
• A mix of clouds and sun and a bit cooler with a good (50%) chance of showers Thursday, mostly cloudy with a (40%) chance of showers Thursday night,
• Then a mix of clouds and sun with a slight (20%) chance of showers Friday.
• 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 evening rain and snow showers, a good (50%) chance of rain and snow showers late tonight (0.50 in. of rain possible, l1 in. of snow possible),
• Mostly cloudy with a slight (20%) chance of AM rain and snow, rain showers with snow showers likely (70%) and a bit warmer Saturday afternoon, rain and snow showers Saturday night,
• Mostly cloudy and a bit warmer with rain and snow showers likely (70%) Sunday, rain and snow showers at night,
• Mostly cloudy and a bit cooler with snow showers and rain showers Monday, mostly cloudy with good (50%) chance of snow and rain showers Monday afternoon, then mostly cloudy with a good (50%) chance of snow and rain showers late Monday night.
• snow level 4,500 ft. tonight and Saturday, 4,500 ft. Saturday night, 4,500 ft. Sunday, 4,500 ft. falling top 3,500 ft. late Sunday night, then 3,000 ft. Monday and Monday night.
• lows 33-25 highs 42-46 cooling 39 Monday.
• A mix of clouds and sun and warmer with snow showers and rain showers likely (70%) and a slight (20%) chance of thunderstorms Tuesday, partly cloudy with a slight (20%) chance of thunderstorms and snow showers Tuesday night,
• Mostly sunny and a bit warmer with a slight (20%) chance of rain and snow showers Wednesday, a good (50%) chance of rain and snow showers at night,
• Mostly cloudy with rain and snow showers likely (70%) Thursday, a good (50%) chance of rain and snow showers Thursday night,
• Then a mix of clouds and sun with a good (50%) chance of rain and snow showers Friday.
• snow level  3,500 ft. Tuesday at the surface Tuesday night, 5.000 ft. Wednesday, then 5,500 ft. Wednesday night through Friday.
• highs 44-52 lows 27-33.