In just over a years time, the nations rainfall fortunes have shifted suddenly and dramatically. Rainfall famine has turned to rainfall feast.
The amount of U.S. real estate covered by drought is about as low as it has been in recent decades, the National Oceanic and Atmospheric Administration reported Wednesday. Drought affects just 2 percent of the country about the smallest area since the federal government began official monitoring in 2000.
Meanwhile, NOAA data show the last 12 months (May 2018 to April 2019) were the wettest on record for the nation. Averaged across the contiguous U.S., the total of 36.20 inches made the period from May 2018 to April 2019 the first year-long span ever to top 36 inches, wrote Bob Henson on Weather Undergrounds Category 6 blog. U.S. precipitation records date back to 1895.
Heavy precipitation extremes have been a staple of U.S. climate conditions over the past year whether Hurricane Florences record-setting rain in the Carolinas, Washingtons wettest year on record, a sopping wet winter in California, and recent flooding in the central United States.
The sudden lack of drought is remarkable considering that in January 2018, nearly 40 percent of the nation suffered from a lack of precipitation. But since then, storm after storm has eaten away at the dry conditions.
Much of drought relief came in a span of just three months this past winter. As recently as December, over 20 percent of the nation still suffered from a shortage of precipitation. Then, the Lower 48 posted its wettest winter on record and the territory affected by drought shrank remarkably.
Nowhere has precipitation fortunes changed as quickly or as radically as in California. In December, 75 percent of the state was in drought. That amount sank to zero after a stormy winter. More than 20 atmospheric rivers, streams of moisture from the Pacific, bombarded the state. Plant life exploded, and the state enjoyed a magnificent super bloom this spring.
El Niño, the episodic warming of waters in tropical Pacific Ocean, is certainly a major driver of the rainfall recovery. It tends to pump subtropical moisture toward the West Coast and nudge the prevailing storm track across the southern part of the country. Here weather systems can draw moisture from not only the Pacific but also the Gulf of Mexico. NOAA projects that El Niño could persist into next winter, so there is no reason to expect drought to quickly rebound.
NOAA tweeted Wednesday that these historically low drought levels are good news. But the rapid increase in rainfall over the nation could also be too much of a good thing.
While the lack of drought is a positive for places such as California that were desperate for water, this springs excessive rainfall has resulted in historic flooding in parts of the central United States. In its spring outlook, NOAA warned that flooding could be unprecedented in some areas, and that has played out.
Recall the March bomb cyclone that became a $4 billion flooding disaster in Nebraska, Iowa, Missouri, South Dakota, Minnesota and Wisconsin? Since then, additional historic flooding has hit the upper Midwest and Mississippi River basin, with the river level in Davenport, Iowa, reaching its highest crest recorded.
More than 100 river and stream gauges, mostly in the central United States, are reporting moderate to major flooIding.
A powerful spring weather system this week has triggered a new round of flooding in several states in the central United States, and more is expected.
Our meteorologists are predicting rainfall amounts of 5 to 10 inches from southeast Texas into portions of Arkansas, Louisiana, and Mississippi through the weekend with locally higher amounts approaching a foot, the National Weather Service tweeted Wednesday. This intense rainfall will lead to dangerous flooding.”
Over the next two weeks, at least, the Weather Service projects wetter-than-normal conditions for large parts of the country. So concerns will continue to center on too much water rather than too little.
