Prolonged Atmospheric River in the Pacific Northwest; Snow and High Winds from the Upper Midwest into the Northeast

A prolonged atmospheric river will continue to impact the Pacific Northwest into the Northern Rockies with heavy rainfall, areas of urban and river flooding, landslides, heavy mountain snow, and gusty winds into Thursday. A strong clipper system will bring the threat of heavy snow and high winds across the Upper Midwest/Great Lakes as well as portions of the interior Northeast and Appalachians. Read More >

NZUS99 KBUF 092352
GLFLOT

Experimental Tabular Open Lake Forecast for Lake Ontario
National Weather Service Buffalo NY
652 PM EST Tue Dec 9 2025

Waves are the significant wave height - the average of the highest
1/3 of the wave spectrum. Occasional wave height is the average of
the highest 1/10 of the wave spectrum.

.SYNOPSIS...A 29.2 inch low will approach the region tonight and
move just northwest of the Lake Wednesday. The region will be
situated between a 29.1 inch low over the Canadian Maritimes and a
30.1 inch high over the Southern Plains Thursday. A 29.9 inch ridge
of high pressure is expected to move into the Great Lakes region
Friday. A 29.8 inch low may move north of the Lake on Saturday, then
30.2 inches will average across the Lower Great Lakes region between
the departing low to the east and a 30.7 inch high over the Plains
Sunday.

LOZ062-100900-
Lake Ontario open waters from the Niagara River to Hamlin Beach-
652 PM EST Tue Dec 9 2025

.Overnight...
Weather.............Snow likely, then rain and snow after midnight.
Sfc winds...........Southwest 20 to 25 knots.
100-ft winds........Southwest to 30 knots.
Sig waves...........6 to 9 feet.
Ocnl waves..........Around 11 feet.

.WEDNESDAY...
Weather.............Rain and snow, then rain in the afternoon.
Sfc winds...........South 20 to 25 knots.
100-ft winds........Southwest to 30 knots.
Sig waves...........5 to 7 feet.
Ocnl waves..........Around 9 feet.

.WEDNESDAY NIGHT...
Weather.............Mostly cloudy with chance of snow showers, then
                              mostly cloudy with snow likely after midnight.
Sfc winds...........West to 30 knots.
100-ft winds........West gales to 35 knots.
Sig waves...........6 to 9 feet.
Ocnl waves..........Around 12 feet.

.THURSDAY...
Weather.............Mostly cloudy with chance of snow showers, then
                              partly sunny in the afternoon.
Sfc winds...........West to 30 knots.
100-ft winds........West gales to 35 knots.
Sig waves...........6 to 9 feet.
Ocnl waves..........Around 12 feet.

.THURSDAY NIGHT...
Weather.............Mostly cloudy.
Sfc winds...........West 20 to 25 knots.
100-ft winds........West to 30 knots.
Sig waves...........6 to 9 feet.
Ocnl waves..........Around 10 feet.

.FORECAST DAYS 3 THROUGH 5......
.FRIDAY...Chance of snow showers. West winds 15 to 20 knots.
Waves 3 to 5 feet.
.SATURDAY...Windy. Chance of snow showers, then snow showers
likely after midnight. West winds to 30 knots. Waves 6 to 9 feet.
.SUNDAY...Breezy. Chance of snow showers. West winds 20 to
25 knots. Waves 4 to 6 feet.

$$

LOZ063-100900-
Lake Ontario open waters from Hamlin Beach to Sodus Bay-
652 PM EST Tue Dec 9 2025

.Overnight...
Weather.............Cloudy with chance of snow showers, then rain
                              and snow after midnight.
Sfc winds...........South 20 to 25 knots.
100-ft winds........South to 30 knots.
Sig waves...........5 to 7 feet.
Ocnl waves..........Around 9 feet.

.WEDNESDAY...
Weather.............Rain and snow, then rain in the afternoon.
Sfc winds...........South 20 to 25 knots.
100-ft winds........South to 30 knots.
Sig waves...........5 to 7 feet.
Ocnl waves..........Around 9 feet.

.WEDNESDAY NIGHT...
Weather.............Mostly cloudy with rain with snow likely, then
                              mostly cloudy with snow likely after midnight.
Sfc winds...........West to 30 knots.
100-ft winds........West gales to 35 knots.
Sig waves...........8 to 12 feet.
Ocnl waves..........Around 14 feet.

.THURSDAY...
Weather.............Mostly cloudy with chance of snow showers.
Sfc winds...........West gales to 35 knots.
100-ft winds........West gales to 45 knots.
Sig waves...........10 to 14 feet.
Ocnl waves..........Around 16 feet.

.THURSDAY NIGHT...
Weather.............Mostly cloudy.
Sfc winds...........Northwest to 30 knots.
100-ft winds........Northwest gales to 35 knots.
Sig waves...........8 to 12 feet.
Ocnl waves..........Around 14 feet.

.FORECAST DAYS 3 THROUGH 5......
.FRIDAY...Chance of snow showers in the morning. chance of snow
showers after midnight. West winds 15 to 20 knots. Waves 4 to
6 feet.
.SATURDAY...Windy. Snow showers likely in the morning, then
chance of snow showers in the afternoon and evening. snow showers
likely after midnight. Southwest winds to 30 knots. Waves 8 to
12 feet.
.SUNDAY...Windy. Chance of snow showers. West winds to 30 knots.
Waves 6 to 9 feet.

$$

LOZ064-065-100900-
Lake Ontario open waters from Sodus Bay to Mexico Bay-
Lake Ontario open waters from Mexico Bay to the Saint Lawrence
River-
652 PM EST Tue Dec 9 2025

.Overnight...
Weather.............Cloudy with chance of snow showers, then cloudy
                              with snow after midnight.
Sfc winds...........South to 30 knots.
100-ft winds........South gales to 35 knots.
Sig waves...........6 to 9 feet.
Ocnl waves..........Around 12 feet.

.WEDNESDAY...
Weather.............Snow and rain, then rain in the afternoon.
Sfc winds...........South to 30 knots.
100-ft winds........South gales to 35 knots.
Sig waves...........6 to 9 feet.
Ocnl waves..........Around 11 feet.

.WEDNESDAY NIGHT...
Weather.............Rain with snow likely, then mostly cloudy with
                              chance of snow showers after midnight.
Sfc winds...........Southwest to 30 knots becoming west gales to 35
                              knots after midnight.
100-ft winds........Southwest gales to 35 knots becoming west at 45
                              knots after midnight.
Sig waves...........8 to 12 feet.
Ocnl waves..........Around 14 feet.

.THURSDAY...
Weather.............Mostly cloudy with chance of snow showers.
Sfc winds...........West gales to 35 knots.
100-ft winds........West gales to 45 knots.
Sig waves...........10 to 14 feet.
Ocnl waves..........Around 17 feet.

.THURSDAY NIGHT...
Weather.............Mostly cloudy with chance of snow showers.
Sfc winds...........West to 30 knots.
100-ft winds........West gales to 35 knots.
Sig waves...........8 to 12 feet.
Ocnl waves..........Around 15 feet.

.FORECAST DAYS 3 THROUGH 5......
.FRIDAY...Chance of snow showers in the afternoon and evening.
snow showers likely after midnight. West winds 15 to 20 knots.
Waves 5 to 7 feet.
.SATURDAY...Windy. Snow showers likely. Southwest winds to
30 knots. Waves 8 to 12 feet.
.SUNDAY...Breezy. Snow showers likely in the morning, then chance
of snow showers in the afternoon and evening. West winds 20 to
25 knots. Waves 6 to 9 feet.

$$

LOZ061-100900-
MAFOR 1004/
ONTARIO WEST 1/2 11537 11527 12427 11526 11636 11637 11730. A
chance of snow showers Wednesday evening. Waves 4 to 7 feet
subsiding to 3 to 5 feet overnight. Waves 2 to 4 feet building to
3 to 6 feet Wednesday. Waves 5 to 8 feet Wednesday evening.

ONTARIO EAST 1/2 11540 11430 12437 11537 11536 11636 11637. A
chance of snow showers late this evening, then a chance of rain
showers overnight. Waves 5 to 8 feet overnight. Waves 3 to 6 feet
building to 5 to 8 feet Wednesday. Waves 5 to 9 feet Wednesday
evening.

$$