This week’s drought summary
Two atmospheric river events struck California and portions of neighboring states, with the second arriving as the drought-monitoring period ended. Torrential rain in central California caused a levee break along the Pajaro River, flooding the community of Pajaro in Monterey County. Rain, along with melting of lower-elevation snowpack and dam releases, also led to significant water rises along many waterways in California’s Central Valley. By March 15, the San Joaquin River at Patterson, California, neared a record crest, with the water rising to within less than a foot of the February 2017 high-water mark. The average mid-March water equivalency of the high-elevation Sierra Nevada snowpack topped 55 inches, more than 220% normal for an entire season, according to the California Department of Water Resources. Most other areas of the West received mostly light to moderately heavy precipitation. Farther east, storms delivered light to moderately heavy snow across the northern Plains and upper Midwest, with some of the most significant precipitation falling on March 11. Meanwhile, a band of heavy showers (locally 2 to 4 inches) stretched from northeastern Texas to the southern Appalachians, before shifting into the Deep South. Notably, northern Florida and environs received much-needed rain, following an extended period of record-setting warmth. Farther north, a powerful coastal storm developed as the monitoring period ended, battering parts of the Northeast with heavy, wet snow and high winds. Mostly dry weather covered the remainder of the country, including the central and southern High Plains, the Rio Grande Valley, and southern Florida. Elsewhere, chilly conditions dominated areas from the Pacific Coast to the northern half of the Plains, while record-setting warmth finally ended cross the Deep South. In fact, freezes were reported for several days, starting on March 14, as far south as Alabama, Georgia, and Mississippi.
The “hot spot” for drought in South remained the southern tier of the region, across northern, central, and western Oklahoma and roughly the western two-thirds of Texas. According to the U.S. Department of Agriculture, 68% of the rangeland and pastures in Texas were rated in very poor to poor condition on March 12, along with 50% of the winter wheat and 47% of the oats. Additionally, statewide topsoil moisture in Texas was rated 69% very short to short, with values ranging from 92 to 100% very short to short across the Northern and South High Plains, Trans-Pecos, Edwards Plateau, Coastal Bend, and the South region. Meanwhile in Oklahoma, statewide topsoil moisture was categorized as 49% very short to short. Rangeland and pastures in Oklahoma were rated 60% in very poor to poor condition on March 12, while 44% of the state’s winter wheat was rated very poor to poor. Notably, an extremely sharp gradient existed across eastern sections of Oklahoma and Texas between drought-free conditions to the east and moderate to exceptional drought (D1 to D4) to the west. Elsewhere, moderate drought (D1) expanded across southern Louisiana, where New Orleans, reported just 5.72 inches of rain (51% of normal) for the year to date through March 14.