The remarkable Arctic cold blast that brought dangerously cold wind chills of -30°F or lower to at least nineteen states is winding down today. Tuesday's high
temperature in Detroit
struggled to just -1°F. It was just the fourth time in recorded history
that the high temperature had failed to reach zero. In Buffalo, New York
, Tuesday's epic lake effect blizzard dumped 12.6" of snow on the city, with up to 25" falling in nearby regions. Another 2 - 3" are expected on Wednesday as the winds over Lake Erie wind down and temperatures warm up. Temperatures will moderate to levels about 10 - 20° below normal on Wednesday, in contrast to the 20 - 40° below normal temperatures commonly observed on Monday and Tuesday over large portions of the eastern half of the United States. By Friday, the majority of the U.S. will see above normal temperatures, and by Saturday, high temperatures will be up to 40°F warmer than Tuesday's highs over much of the Midwest.Figure 1.
Arctic air flowing over the Lake Erie on January 7, 2014 created two major bands of lake-effect snow snow near Buffalo, New York. Image credit: NASA.Figure 2.
For those of you who have to be texting out in the cold, there's always the texting mitt sold by FE Clothing.Not a Historic Cold Wave
As notable as this week's cold wave was--bringing the coldest air seen since 1996 or 1994 over much of the nation--the event failed to set any monthly or all-time record low minimum temperature records at airports and cooperative observing stations monitored by NOAA's National Climatic Data Center.
As wunderground's weather historian Christopher C. Burt summed it up for me, "The only significant thing about the cold wave is how long it has been since a cold wave of this force has hit for some portions of the country--18 years, to be specific. Prior to 1996, cold waves of this intensity occurred pretty much every 5-10 years. In the 19th century, they occurred every year or two (since 1835). Something that, unlike the cold wave, is a truly unprecedented is the dry spell in California and Oregon, which is causing unprecedented winter wildfires in Northern California."
Part of the reason that this week's cold wave did not set any all-time or monthly cold records is that it is becoming increasingly difficult to do so in a warming climate. As Andrew Freedman of Climate Central wrote in a blog post yesterday,
"While the cold temperatures have been unusual and even deadly, climate data shows that intense cold such as this event is now occurring far less frequently in the continental U.S. than it used to. This is largely related to winter warming trends due to man-made global warming and natural climate variability."
For example, in Detroit during the 1970s, there were an average of 7.9 nights with temperatures below zero. But this decade, that number has been closer to two nights.Figure 3.
Trend in frigid nights in Detoit from the 1970s to the most recent decade. Yellow line indicates linear trend since 1970. Image credit: Andrew Freedman, Climate Central