On average 4.36 inches of rain and snow — mostly rain — fell over the Lower 48 in May, sloshing past October 2009 which had been the wettest month in U.S. records with 4.29 inches. National Oceanic and Atmospheric Administration records go back to 1895.
NOAA climate scientist Jake Crouch calculated that comes to more than 200 trillion gallons of water in May.
For the time being, the outlook for the Austin area is sunny and dry. Forecasters with the National Weather Service call for dry, hot weather in Central Texas through the end of the week, with highs in the 90s under partly cloudy skies.
Friday brings a 20 percent chance for thunderstorms, with odds edging up to 50 percent on Saturday, prompted by the arrival of a front from the Gulf of Mexico. Sunday has a 40 percent for showers.
Crouch said the record wet weather in May was triggered by a stalled pattern of storms that dumped massive amounts of rain in the central U.S., especially in Texas and Oklahoma, which had their rainiest months.
Texas and Oklahoma had been in a five-year drought and it was washed away in just one month, Crouch said: "It's like one disaster ending a catastrophe."
Nine people have been found dead in Central Texas in connection with the Memorial Day weekend floods. William Randall Charba, 42, William Charba, 6, and Leighton McComb, 4, are all still missing. They were part of a group of three Corpus Christi families visiting Wimberley when the flood tore their vacation house off its foundation.
Statewide, at least 28 people in Texas were killed in the Memorial Day weekend storms. More than two dozen counties in Texas — including Travis, Hays, Williamson, Bastrop, Blanco and Caldwell — received a disaster declaration by the Federal Emergency Management Agency. The declaration offers federal aid to supplement other recovery efforts in the areas affected by severe weather since May 4.
Colorado had its rainiest May on record. Arkansas, Nebraska and Utah had their second-wettest month on record. Fourteen states had one of their 10 rainiest Mays on record — all of them west of the Mississippi River and east of California.
Still, parts of the Northeast were unusually dry. It was the second-driest May for Massachusetts and the third-driest May for Rhode Island and New Jersey.
Last month was 1.45 inches wetter than 20th century average for May. It was only the seventh time the entire contiguous United States averaged four inches of rain or more.
The global climate phenomenon El Niño, which starts with a warming in the central Pacific and changes weather worldwide for a year or so, is usually associated with such heavy rainfall, Crouch said. He added that it is too early to say if it triggered the record moisture. Though more heavy downpours are expected as the world warms, Crouch said there's no way to connect climate change to a single, soggy month.
May's average temperature in the U.S. was 60.8 degrees, which is slightly warmer than the 20th century average. However, Connecticut, Massachusetts, New Hampshire and Rhode Island had their warmest Mays on record.
©2015 Austin American-Statesman, Texas. Distributed by Tribune Content Agency, LLC.
