Both the winters of 1997-1998 and the present featured El Niño events, which tend to increase the flow of Pacific moisture into the Lower 48 states.
Of the three winter months this year, the finale was particularly soggy, ranking second-wettest on record. Nineteen states posted one of their 10 wettest Februaries. Tennessee registered its wettest February, while the month ranked second-wettest in Kentucky and Wisconsin.
The February deluges in the Tennessee Valley spurred flooding along the Mississippi River and mudslides in Tennessee and North Carolina.
From the mid-South to the Tennessee Valley, record February rainfall was logged in numerous population centers, including Knoxville (13.08 inches); Nashville (13.47 inches); Bristol, Tenn. (10.47 inches); Tupelo, Miss. (15.61 inches); Muscle Shoals, Ala. (14.13 inches); and Huntsville, Ala. (13.63 inches).
Greg Carbin, a meteorologist with the National Weather Service, told The Washington Post that a record 5.5 percent of the Lower 48 received more than 10 inches of rain in February.
Heavy precipitation visited the northern tier, as well.
The zone from the Pacific Northwest to the Great Lakes was hit repeatedly by winter storms that unloaded historic amounts of snow.
Record February snowfall was observed in Seattle (20.2 inches); Pendleton, Ore. (32.5 inches); Great Falls, Mont. (31.3 inches); Rochester, Minn. (40.0 inches); Minneapolis (39.0 inches); and Eau Claire, Wis. (53.7 inches).
In addition, numerous ski areas in the Sierra Nevada, blasted by a series of atmospheric rivers, witnessed record snowfall in February. Mammoth Mountain and Squaw Valley reported record snowfall over 200 inches.
For the winter overall, all but five of the Lower 48 states reported above-normal precipitation.
U.S. precipitation over the past three, six and 12 months has been unsurpassed.
While precipitation over a short period cannot be conclusively linked to climate change, a greater frequency of heavy downpours is projected in a warming world, which would increase the likelihood of any given period being abnormally wet.