According to the April 24, 2018, U.S. Drought Monitor, moderate to exceptional drought covers 29.0% of the contiguous United States, a slight increase from last week’s 28.9%. Extreme and exceptional drought—the worst categories—expanded to cover 8.5% of the Lower 48, up from 8.2% last week.
April is in the middle of the spring transition season when the storm track normally contracts to the north, to be replaced by high pressure ridging from the south. During this U.S. Drought Monitor week, ridging tried to become established over the continent, but two strong weather systems moved across the contiguous United States in a more southerly track as a vigorous upper-level circulation continued.
The upper-level weather systems dragged fronts and low pressure systems along with them, resulting in a cooler-than-normal week for most of the Lower 48. These systems were relatively dry as they crossed the West, but they tapped Gulf of Mexico and Atlantic moisture once they crossed the Rockies to bring above-normal precipitation to parts of the Plains and much of the Southeast.
As a result, most of the West to the Rio Grande Valley was drier than normal, with drought expanding or intensifying in places. The southerly storm track also resulted in a drier-than-normal week from the Midwest to Northeast. Beneficial rains finally fell across the core drought area in the southern Plains, but it generally wasn’t enough to show drought improvement. However, drought and abnormal dryness contracted across the Southeast where above-normal rains fell.
Abnormal dryness and drought are currently affecting over 91 million people across the United States—about 29.3% of the country’s population.
In addition to Drought.gov, you can find further information on the current drought as well as on this week’s Drought Monitor update at the National Drought Mitigation Center. See their recent news releases.
The most recent U.S. Drought Outlook is available from NOAA’s Climate Prediction Center and the U.S. Department of Agriculture provides information about the drought’s influence on crops and livestock.