Cold snaps are often part of life in North America. Some reach the status of legend such as the cold snaps of 1899, 1936, the late 1970s, or December 1983. The one in December 1983 brought the coldest December on record for Omaha. Just 6 years later, another brutal cold snap in December 1989 would freeze the nation. Albeit not as long-lasting as the one in 1983, it was more intense in terms of cold.
In this installment of This Week in Weather History, we look back at the week the nation froze right before Christmas.
THE ANATOMY OF A COLD SNAP
Our weather patterns are driven by that high-level belt of fast-moving air, the jet stream, that moves west to east across the country. The jet stream is not a steady flow but oscillates constantly in waves across the country. A dip in the jet stream, called a trough, allows colder weather to spill in from Canada. A bump in the jet stream, called a ridge, allows warmer air from the tropics to push northward. This is why the US constantly switches from warm to cold air masses.
Rarely do conditions line up to allow for a huge push of truly arctic air to invade the US. This happened in many historic cold snaps and would occur in December 1989. For much of the month, the jet stream became "stuck" with a large ridge over the western US/Pacific Ocean and a big trough in the eastern US. This would allow uninhibited flow of cold air from Canada into the US. This, alongside other climatological factors known as teleconnections lining up, created the recipe for the December 1989 cold snap.
Signs of the impending cold were seen as early as the 18th when forecasters noted a powerful high-pressure system screaming southward in Canada. Pressure in meteorological terms is measured in millibars. The standard pressure at any given point is around 1013 mb, anything higher is considered a "high-pressure system" while anything lower is a "low-pressure system". A typical high-pressure system for Nebraska would record anything between 1020-1035 mb, anything higher than that would be considered rare. The high pressure in Canada at that point was around 1055 mb, which if it held its strength would be some of the highest pressure ever recorded in the United States. When it moves over Omaha, the highest pressure recorded at Eppley Airfield was 1053.7 mb, the second-highest reading ever recorded at the airport (records date back to 1948). It was beaten by a 1055.3 mb reading on January 7, 2015.
THE COLD IN OMAHA
It was average and warm even for the first week of December 1989. Omaha's high reached 63 degrees on December 5, and on a few other days, highs topped out in the 50s.
Things took an abrupt turn around December 13th when the first major arctic blast shuttered the US. Some snow fell in Omaha which caused some slowdowns along with a few accidents, but the bigger story was the cold. High temperatures on December 14 did not rise above 0, and low temperatures crashed into the -15 range on the 15th. This low in Omaha broke the record low. Chadron in northwest Nebraska dropped to -30, the coldest temperature in the nation. Schools were closed, sporting events and other outdoor activities were canceled, and pipes burst. By the 16th, the air warmed some with highs returning above zero. Omaha and the Midwest could catch its breath. Yet the worst was still to come.
December 18th brought a new round of snow to Omaha, 2-4", which caused some issues. The evening commute was slow as numerous accidents occurred on the snow-packed roads. In Iowa, I-80 near Shelby had many problems as several cars slid off the interstate. By the 19th, most of the snow had been cleared from the main roads. Highs were in the single digits with lows well below zero.
The influence from the powerful high made its presence known by December 20th. The high reached 6 and the low fell to -8 by midnight, then continued to fall into the 21st. An inch of snow fell too, causing more issues with roads.
December 21st sat in the -15 range for most of the day, a 20-35 mph wind sent the wind chill value to close to -50 at times! The wind chill of -50 is one of the lowest wind chills observed at Eppley Airfield since it began recording data in 1948. Tow truck drivers spent all day jump-starting cars, and semi-trucks had the diesel fuel begin to jell up. Schools were closed area-wide as the cold became dangerous to be out in for more than a few minutes.
Omaha hit rock bottom in the cold on the morning of December 22 with a low of -25 degrees. Not only is this a record for the day, but it's the third-lowest temperature ever recorded in Omaha. The two above it are -26 on February 11, 1899, and -32 on January 5, 1884. Wind chills hovered around -45 for much of the morning. Elsewhere in the state, lows dropped to below -40 in the panhandle, the record low temperature for Nebraska was tied at -47 on December 22nd.
The 22nd would be the worst, by the 23rd it started to warm up. Shockingly, Christmas Day was surprisingly mild with a high of 42. The toll in Nebraska and Iowa was severe with many burst pipes, stalled cars, and cold-related injuries. One homeless man was treated at the hospital for severe frostbite. A few others tragically lost their lives shoveling snow after suffering heart attacks.
THE TOLL ON THE NATION
Omaha was not the only place to experience the brutal cold in the days before Christmas, much of the eastern half of the nation did too. Records were shattered across the Midwest as Chicago and St. Louis experienced lows of -10 to -20 degrees. The cold spread into the south, where the worst impacts were felt. Temperatures in Houston dropped to 7 degrees, the coldest since the 19th century. Dallas reported 25 million dollars in damage from burst pipes.
The arctic air combined with a low-pressure system in the southeast to produce one of the worst snowstorms in the history of the region. Snow fell from northern Florida to the Carolinas. Wilmington NC saw its highest snowfall on record with 15.3", and Charleston SC also broke its all-time record with 8". Snow fell in northern Florida, with Jacksonville receiving 0.8" and snowflakes being reported in Tampa. The snow stuck to Christmas, bringing parts of Florida its only white Christmas in recorded history.
In Florida, the cold impacts were uniquely devastating. 26 people died as a direct result of the cold. Desperate attempts to keep pipes working were made, such as Gator Bowl Stadium in Jacksonville flushing all of their toilets simultaneously to keep the pipes moving. Airports shut down as de-icing equipment failed. The cold also brought untold impacts on the citrus industry, with around 1/3rd of the entire crop being wiped out due to the cold. The impacts were so severe, it has permanently altered the landscape of the citrus industry in Florida today.
Across the US, the December 1989 cold wave killed upwards of 100 people directly or indirectly and led to millions of dollars in damage. It remains one of the worst cold waves to impact the country in recent memory.
