(CNN)There’s never been a wetter 12 months than the period that recently ended, reported the National Weather Service, which has been keeping such records for 124 years.
It’s all a result of hurricanes, atmospheric rivers
and the very wet autumn that unfolded between May 1, 2018, and April 30. The effect fits the broad trend of climate change pushing up US precipitation totals
The continental United States averaged 6 inches of precipitation above average during the one-year period, with 36.2 inches tallied. That blew away the previous record, set in 2015 and 2016, by almost half an inch.
A map created by NASA shows just how much groundwater there was on May 13, 2019, compared with previous months of May. Areas in blue have more groundwater than previous Mays; places in orange and red have less.
Hurricanes, bomb cyclones and El Niño
dumped massive amounts of rain last year across the Southeast. Atmospheric rivers, which suck water vapor from the ocean and dump it on land, deluged California with rain and snow, helping to pull the state out of drought. And the El Niño
weather pattern — with warming, eastward-moving Pacific waters — contributed to the new benchmark.
Rapidly strengthening storms known as bomb cyclones
in the winter
across the central US also helped bury the previous record.
The exceptional snowfall and rainfall set the stage for a treacherous snowmelt and spring in the Midwest, where huge swaths remain flooded
. Though it’s not counted in the new record, the torrent has continued across the Arkansas River Valley in Kansas and Oklahoma, with rainfall 200% above average between May 1 and 27, according to the Arkansas-Red Basin River Forecast Center.
Climate change has forced precipitation records to topple more frequently.
“Heavy precipitation events in most parts of the United States have increased in both intensity and frequency since 1901,” a report from the US Global Change Research Program found. “The frequency and intensity of heavy precipitation events are projected to continue to increase over the 21st century.”
Read more: https://www.cnn.com/2019/05/30/us/wettest-12-months-continental-us-wxc-trnd/index.html