Tuesday was a top 10 day — just not in a good way.
The temperature in Omaha dropped to its seventh lowest on record for Nov. 12, said Natalie Umphlett, regional climatologist at the High Plains Regional Climate Center.
The Omaha temperature bottomed out at 11 degrees at 6:57 a.m. — a good distance from the record low of 1 degree set Nov. 12, 1911, but still some 20 degrees below the average low of 31 degrees.
Records date to 1871.
Several factors combined to make the day so cold. The mass of Arctic air that plunged southward had been bottled up, which allowed the cold to intensify before it finally broke loose.
Another factor was the intense high pressure that settled over the region.
The pressure reading over Omaha on Tuesday morning was the highest since Jan. 15, 2009, said Cathy Zapotocny, meteorologist with the National Weather Service.
High pressure causes winds to die down, which allows warm air to lift away from the Earth and cold air to pool at the surface.
Wednesday's forecast high of 52 will be about 20 degrees warmer than Tuesday's high. That rapid shift in temperature, from one day to the next, is similar to what happened the last time the pressure was higher.
On Jan. 15, 2009, the day's high peaked at 2 degrees and the overnight low dropped to 16 degrees below zero.
On the day before and day after — which lacked the chilling effect of the high-pressure readings — the day's highs were more tolerable. On the day before the high was 38 degrees, and the day after it was 20 degrees, she said.