Jeff Masters Weather Blog

Winter weather brings pre-holiday chaos » Yale Climate Connections

The entire central third of the United States was covered by windchill watches and warnings on Wednesday morning, signaling one of the most dramatic and dangerous pre-Christmas cold waves in U.S. history. An intense cold front gathering strength and speed over the Northern Plains on Wednesday morning will have plowed all the way to the Gulf and Atlantic coasts by Saturday, Christmas Eve.

The leading edge of the cold air pushed far enough west on Tuesday to dump snow over parts of the far Pacific Northwest, including Seattle and Vancouver. Another round of snow and/or freezing rain will afflict the region on Thursday and Friday, potentially bringing major impacts as far south as the Columbia River, including Portland.

Driving the Arctic air south and east across the United States will be a sprawling zone of high pressure that forecast models suggest could top the highest surface pressure ever recorded in the contiguous U.S.:  1064 millibars (31.42 inches of mercury), recorded at Miles City, Montana on Dec. 24, 1983, during a similar preholiday winter onslaught. (That 1983 cold wave was so intense and widespread that many of its low-temperature records will be difficult to dislodge over the next few days, despite the intensity of the winter weather now on tap.)

Life-threatening wind chill values, in some cases far below zero Fahrenheit, will affect tens of millions of people this week. Fierce winds gusting to 40–60 mph over vast areas will whip fine, powdery snow across the landscape, leading to blizzard and near-blizzard conditions behind the front from Minnesota to Michigan and potentially as far southwest as Oklahoma. Blizzard conditions are defined as snow and/or blowing snow reducing visibility to a quarter mile or less in winds gusting above 35 mph for a period of three hours or more.

Wednesday morning computer model forecasts indicated that the moisture supply for the blizzard will be more limited than previously thought, resulting in lower snowfall totals. Snowfall amounts behind the fast-moving front will generally be well under a foot. However, major drifts and white-out conditions are still expected. The bitter cold, frigid winds, and blowing snow will make highway travel inadvisable when not impossible over large parts of the Midwest, even after the snow stops falling. Flight delays and cancellations will hobble much of the U.S. aviation system during the crucial pre-Christmas travel window. Major airlines were offering waivers for customers to switch flights out of dozens of major airports through Christmas weekend.

A quick-hitting Arctic blast

While not expected to be the most frigid or most prolonged cold wave in U.S. history, this week’s front will be among the sharpest and most dramatic in recent decades – and quite dangerous, given the raging and bitterly cold winds expected. In Dillon, Montana, the temperature dropped a remarkable 26 degrees Fahrenheit in just three minutes on Wednesday morning, falling to 1°F at 4:25 a.m. MST, while the winds went from calm to 32 mph with gusts of 39 mph.

In the Denver area, forecasters were predicting that temperatures would drop from the 40s Fahrenheit to values below zero in just three hours on Wednesday afternoon and evening.

The Arctic air will plunge across the Great Plains from Wednesday into Thursday as a “blue norther,” racing toward the Gulf Coast at speeds of 25-30 mph or greater. The front should move through all of western Kansas in less than six hours, with temperatures dropping by 50 degrees Fahrenheit or more in a matter of hours.

It’s even possible the front will arrive with a wall of dust in some parts of the drought-stricken High Plains, à la stark photographs from the 1930s Dust Bowl.

In Texas, temperatures could stay below freezing for more than 36 hours in Houston and up to 72 hours in the Dallas-Fort Worth area, likely into Saturday. This cold wave won’t be as intense or long-lasting as the catastrophic one that sent the Texas power grid to its knees in February 2021, but frozen and bursting pipes are still a major concern.

Figure 1. Surface temperatures (in degrees Fahrenheit) predicted by the Tuesday-night run of the GFS model for 7 a.m. Friday, Dec. 23. (Image credit:

A topsy-turvy temperature map

As a low-pressure center along the cold front slows down and “bombs out” in Michigan and Ontario late Thursday and Friday, the intense cold front will wrap around its southern end, leading to a spectacular and unusual temperature pattern that briefly bucks the standard warmer-to-the-south, colder-to-the-north tendency (see Figure 1).

In Michigan, it’s quite possible that temperatures will hover around the freezing mark in the eastern Upper Peninsula around sunrise Friday even as they are plummeting to near zero Fahrenheit toward the southern end of the state!

Figure 2. Predicted wave heights on Lake Michigan at 4 p.m. EST Friday, Dec. 23, from the 2 a.m. EST Dec. 21 run of the WaveWatch III model. The southeastern shore of Lake Michigan between Muskegon and Benton Harbor is predicted to get sustained winds of 50 – 60 mph on Friday. (Image credit: NOAA/GLERL)
Figure 3. Predicted wave heights on Lake Erie at 7 p.m. EST Friday, Dec. 23, from the 2 a.m. EST Dec. 21 run of the WaveWatch III model. (Image credit: NOAA/GLERL)

Buffalo braces for a blizzard with epic Lake Erie flooding

The ferocious winds of the blizzard will create huge waves of 15-20 feet on all of the Great Lakes, causing damaging shoreline flooding and dangerous conditions for shipping. The greatest danger of flooding lies on the east shore of Lake Erie in New York in Buffalo. The mighty winds of the blizzard are predicted to blow at 35-55 mph from the southwest along the length of Lake Erie on Friday and Saturday, causing waves on the lake to peak Friday afternoon through Saturday morning at 15-20 feet.

Not only will these winds deliver heavy lake-effect snow, they will also pile up Lake Erie’s waters along the eastern shore and cause major flood problems in Buffalo and Niagara Falls. According to the Buffalo National Weather Service, water levels in Buffalo have the potential to reach 11 feet above the normal low water level sometime between Friday afternoon and Friday night, approaching the record of 12.08 feet set on Dec. 2, 1985. High winds with gusts exceeding 65 mph will be accompanied by heavy snow, wind chills of 10 to 20 below zero, and near white-out conditions, making travel difficult to impossible. Power outages will be a major concern.

Coastal flooding and big waves for the Northeast U.S. and Nova Scotia

Storm-force winds of 60-65 mph are expected on Friday and Saturday along portions of the mid-Atlantic and New England coasts, bringing waves of 15-20 feet and coastal flooding. A coastal flood watch is in effect for portions of Rhode Island, Massachusetts, New Hampshire, and western Maine. A storm surge of 1.5-3 feet is expected in Massachusetts and Rhode Island, causing minor to moderate flooding. The National Weather Service in Maine is warning of a potential storm surge of four feet on the coast of western Maine, which has the potential to bring a top-10 water level on record if the peak surge aligns with the time of high tide. Waves up to 25 feet high are predicted for the offshore waters of Nova Scotia, Canada, on Saturday, when the potential for damaging storm surge flooding is expected during the high tide cycles.

On the east shore of Chesapeake Bay, Maryland, two tide gauges are predicted to approach the major flood threshold during the Friday afternoon high-tide cycle. Minor to moderate coastal flooding is predicted along the shores of Delaware, New Jersey, New York, and Connecticut during the Friday morning high-tide cycle.

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