The Lower 48 shivered this morning in a November cold snap unrivaled in several decades. The average temperature over the contiguous U.S. fell to a frigid 19.4 degrees F. at 7 a.m. according to a dataset used by forecasters.
All 50 U.S. states, including Hawaii, recorded a low temperature at or below 32 degrees.
Update: all 50 states have now hit freezing this morning, with Mauna Kea, Hawaii and Chepachet, Rhode Island the last two.— Eric Holthaus (@EricHolthaus) November 18, 2014
WeatherBell Analytics meteorologist Ryan Maue found that this morning’s 19.4F estimate for the Lower 48 was the coldest reading since November 30, 1976, when the mercury dipped to 17.8 F. The data record dates back to 1955.
(The 19.4F estimate comes from the Real-Time Mesoscale Analysis, a dataset from the National Weather Service that incorporates local temperature readings as well as model estimates in areas where data coverage is sparse.)
Roughly 85 percent of the Lower 48 was below freezing this morning, according to the data.
Scores of record lows and cold weather milestones were (or are forecast to be) established across the U.S. – from Idaho to Atlanta today. Several examples:
- Atlanta is forecast to have its coldest November afternoon since 1940
- State College, Pa. dipped to 14 F, its earliest excursion into the teens since 1997
- Joplin, Mo. set a record low for November, dropping to 6 degrees.
- Detroit tied a record low for November 18 of 11 degrees (records there date back to 1880)
- Houston had its earliest fall freeze since 1999
- Mount Mitchell, N.C. dropped to 0 degrees.
- Kansas City, Mo. set a record low for the date of 6 degrees, shattering the old record of 14 from 1903
- Boise, Idaho set a record low of 5 degrees this morning
- Record low temperatures were broken at Paducah, Ky, Evansville, Ind., and Cape Girardeau, Mo. of 10, 9, and 8 respectively
For a second straight day, 50 percent of the Lower 48 was covered in snow, the most in the relatively short record (dating back to 2003).
The historic November cold shot reflects an extreme jet stream pattern channeling Arctic air directly into the Lower 48 states. Although the contiguous U.S. is in the deep freeze, on the flip-side of the jet stream see-saw, mild air is streaming into Alaska.
Incredibly, the average temperature of the Lower 48 this morning was about the same as Barrow, Alaska, the Last Frontier’s northernmost town, where the mercury varied between 15 and 20 degrees.
Lest anyone believe today’s cold in the Lower 48 refutes global warming, consider the Northern Hemisphere, overall, is warmer than normal – some 1.35 F degrees above the 1979-2000 baseline.
(Not to mention, we just posted several data centers found it was the warmest October on record globally.)