Here is my weekly weather quiz question for the last time. What is a “Tornado Vortex Signature “? Here is the correct answer. A Tornado Vortex Signature is an image of a tornado on the Doppler radar screen that shows up as a small region of rapidly changing wind speeds inside a mesocyclone. The following velocity criteria is normally required for recognition: velocity difference between maximum inbound and outbound (shear) is greater than or equal to 90 knots at less than 30 nmi and is greater than or equal to 70 knots between 30 and 55 nmi. It shows up as a red upside down triangle on the Storm Relative Velocity Display. Existence of a TVS strongly increases the probability of tornado occurrence, but does not guarantee it; therefore, the feature triggering it must be examined closely by the radar operator. A TVS is not a visually observable feature.
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An Upper Level High Pressure Ridge (“Arch” shape) is sending moisture to the Pacific Northwest. The graphics for days 1-3 show a frontal system moving through the Pacific Northwest between Sunday and Monday. The graphics for days 3-7 Tuesday through Saturday show frontal activity continuing through the period.
Note: Ski Report: Willamette Pass, Hoodoo, and Mt. Ashland are all open for the ski season. Check their Web sites for specific mountain conditions and hours of operation.
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ADVISORIES:
- A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL IS IN EFFECT UNTIL 10 AM SUNDAY ABOVE 3,500 FT. THE NORTH OREGON CASCADES, THE CASCADES OF MARION AND LINN COUNTY, AND THE CASCADES OF LANE COUNTY.
- A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 10 AM SUNDAY ABOVE 4,000 FT. FOR THE EAST SLOPES OF THE OREGON CASCADES.
- A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 7 AM SUNDAY ABOVE 4,500 FT. FOR THE NORTHERN BLUE MOUNTAINS OF OREGON AND THE NORTHWEST BLUE MOUNTAINS.
- A HIGH WIND WATCH IS IN EFFECT FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR THE SOUTH CENTRAL OREGON COAST AND THE CURRY COUNTY COAST.
- A HIGH SURF ADVISORY IS IN EFFECT UNTIL 10 PM TONIGHT FOR THE SOUTH CENTRAL OREGON COAST.
- A HIGH SURF ADVISORY IS IN EFFECT UNTIL 10 PM TONIGHT FOR THE CLATSOP COUNTY COAST AND THE TILLAMOOK COUNTY COAST.
- A HIGH SURF ADVISORY IS IN EFFECT UNTIL 10 PM TONIGHT FOR THE CURRY COUNTY COAST.
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 with evening showers with a slight (20%) chance of thunderstorms, showers likely (70%) late tonight (0.25 in. of rain possible, more in storms),
- AM clouds and sun with a good (50%) chance of showers, mostly cloudy and slightly cooler with rain likely (70%) Sunday afternoon (0.10 in. of rain possible), rain at night (0.50 in. of rain possible).
- Mostly cloudy with rain Monday, rain at night,
- Mostly cloudy and a bit warmer with a good (50%) chance of rain Tuesday, then a slight (20%) chance of showers Tuesday night.
- lows 38-43 cooling to 40 Tuesday night highs 49-53.
- Mostly cloudy and a bit warmer with a good (50%) chance of showers Wednesday, a slight (20%) chance of showers Wednesday night,
- Mostly cloudy and a bit cooler with a slight (20%) chance of rain Thursday and at night,
- Mostly cloudy with a (30%) chance of rain Friday, a good (50%) chance of rain Friday night,
- Then rain Saturday.
- highs 53-52 lows 39-42. (seasonal averages high 46 low 34)
Your College Football Weather Forecast:
Wednesday January 1, 2025:
The Ducks will play either #8 Ohio State or #9 Tennessee in the Rose Bowl, Pasadena, California: Game time to be announced. Way too soon for a preliminary weather forecast.
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HOME WOOD HEATING ADVISORY:
Eugene & Springfield: GREEN – The burning wood is allowed.
Oakridge and Westfir: GREEN – The burning wood is allowed.
The use of pellet stoves is always allowed.
Data courtesy of Lane Regional Air Protection Agency (LRAPA.org)
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Forecast for the Umpqua Valley including Roseburg:
- Mostly cloudy with evening rain and snow showers and a slight (20%) chance of thunderstorms, rain and snow showers likely (70%) late tonight (0.10 in. of rain possible, snow level 2,500 ft.),
- Partly cloudy with a slight (20%) chance of AM rain and snow showers, mostly cloudy with rain likely (70%) Sunday afternoon (0.10 in. of rain possible, AM snow level 2,500 ft.), evening rain likely (70%), rain late Sunday night (0.25 in. of rain possible, evening snow level 3,500 ft.),
- Mostly cloudy and a bit warmer with rain Monday and in the evening, rain likely (70%) late Monday night,
- Mostly cloudy with a good (50%) chance of AM rain, a bit warmer with a slight (20%) chance of showers Tuesday afternoon, mostly cloudy with a slight (20%) chance of showers late Tuesday night.
- lows 39-44 cooling to 42 Tuesday night highs 49-54.
- Mostly cloudy with a (30%) chance of showers Wednesday, a slight (20%) chance of evening showers, just mostly cloudy Wednesday night,
- Mostly cloudy and a bit warmer Thursday, mostly cloudy with a slight (20%) chance of rain at night,
- Mostly cloudy with a slight (20%) chance of rain and a bit warmer Friday and in the evening, rain likely (70%) late Friday night,
- Mostly cloudy with AM rain likely (70%), then rain and a bit cooler Saturday afternoon.
- highs 54-56 cooling to 53 Saturday lows 40-44. (seasonal averages high 48 low 37)
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Forecast for The South Oregon Coast Including Coos Bay and North Bend:
- Mostly cloudy with coastal showers likely (70%) and a slight (20%) chance of thunderstorms while a slight (20%) chance of inland showers tonight (0.10 in. of rain possible),
- Mostly cloudy and a bit warmer with a (30%) chance of coastal showers while a slight (20%) chance of inland showers and a bit warmer Sunday afternoon, mostly cloudy with coastal rain Sunday night while inland evening rain likely (70%) and inland rain late Sunday night (0.25 in. of rain possible), breezy (Wind: S 15-25 mph gusts to 40 mph late evening through the night).
- Mostly cloudy with rain and a bit warmer Monday and breezy (Coastal Wind: S 15-25 mph decreasing to S 10-20 mph while Inland Wind: S 10-20 mph), evening rain, rain likely (70%) late at night,
- Mostly cloudy with a (40%) chance of AM rain, a bit warmer with a slight (20%) chance of showers Tuesday afternoon, then a (30%) chance of showers Tuesday night.
- lows 42-45 cooling to 43 Tuesday night highs 55-60.
- Mostly cloudy with a good (50%) chance of showers Wednesday, a slight (20%) of evening showers, just mostly cloudy late Wednesday night,
- Partly cloudy and a bit warmer with a slight (20%) chance of showers Thursday, mostly cloudy with a (30%) chance of rain at night,
- Mostly cloudy and a bit warmer with a (40%) chance of rain Friday, rain likely (70%) Friday night,
- Then mostly cloudy and a bit cooler with rain Saturday.
- highs 60-62 cooling to 59 Saturday lows 42-45. (seasonal averages high 53 low 40)
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Forecast for the Northern Oregon Cascades including the Cascades in Lane County:
- Mostly cloudy with evening snow showers and rain showers and a slight (20%) chance of freezing rain, snow showers and freezing rain likely (70%) late tonight,
- Mostly cloudy with a good (50%) chance of AM snow showers, snow likely (70%) and slightly cooler Sunday afternoon (0.10 in. of rain possible, 2 in. of snow possible), freezing rain, evening rain and snow likely (70%), then rain and snow late Sunday night (0.25 in. of rain possible, 3-6 in. of snow possible, trace of ice accumulation possible),
- Mostly cloudy with rain and snow Monday, rain and snow at night (snow possibly heavy at times),
- Mostly cloudy and a bit warmer with a slight (20%) chance of showers Tuesday, then mostly cloudy with a slight (20%) chance of showers Tuesday night.
- snow level 2,500 ft. tonight and Sunday, 3,500 ft. rising to 5,000 ft. Sunday night, 4,000 ft Monday and Monday night, 5,000 ft. Tuesday, then 5,500 ft. Tuesday night.
- lows 22-29 highs near 32.
- A mix of clouds and sun and a bit warmer with a (40%) chance of showers Wednesday, mostly cloudy with a slight (20%) chance of showers Wednesday night,
- A mix of clouds and sun and a bit warmer with a slight (20%) chance of rain Thursday, mostly cloudy with a slight (20%) chance of rain at night,
- A mix of clouds and sun with a (40%) chance of rain Friday, a good (50%) chance of rain Friday night,
- Then mostly cloudy and a bit cooler with rain and snow likely (70%) Saturday.
- snow level 6,000 ft. Wednesday, 6,500 ft. Wednesday night, 7,000 ft. Thursday and Thursday night, 7,500 ft. Friday, 7,000 ft. Friday night, then 6,000 ft. Saturday.
- highs 37-42 lows 27-29.