U.S. Drought: Weekly Report for February 14, 2023

According to the February 14, 2023 U.S. Drought Monitor, moderate to exceptional drought covers 34.6% of the United States including Puerto Rico, a decrease from last week’s 35.0%. The worst drought categories (extreme to exceptional drought) decreased from 5.3% last week to 4.7%.

The atmospheric circulation across the contiguous U.S. during this U.S. Drought Monitor week (February 8–14) behaved like it had two personalities. On one hand, a strong westerly flow at jet-stream level moved Pacific weather systems quickly across the U.S.-Canadian border. On the other hand, upper-level low-pressure systems further south moved through a transient ridge over the West before getting cut off from the flow and sluggishly moving across the southern states. 

The rapid movement of the northern systems and divergent pattern for the southern systems resulted in a drier-than-normal week for much of the West and northern Plains states. As the cutoff lows tarried over the Southwest, they created an upper-level trough over the West which resulted in a cooler-than-normal week for much of that region as well as the southern Plains. The cutoff lows and their cold fronts and surface low-pressure systems tapped Gulf of Mexico moisture as they moved east, spreading above-normal precipitation across the southern Plains to Great Lakes, along the Gulf Coast, and up to the Mid-Atlantic coast. Between these wet areas lay a band of drier-than-normal weather that extended from the Tennessee Valley to southern New England. 

Southern weather systems triggered a bout of severe weather across the Mississippi Valley early in the week. Because the westerly jet stream along the northern border kept cold air bottled up in Canada, much of the contiguous U.S. east of the Rockies was warmer than normal for the week. Drought or abnormal dryness contracted across parts of the Plains to the Mississippi Valley, along the Southeast coast, and in parts of the Southwest. Here precipitation was above normal but it expanded or intensified in a few areas in northern parts of the West, in the southern Plains, and in parts of Florida where the week was drier than normal. 

Nationally, contraction exceeded expansion, with the nationwide moderate to exceptional drought area decreasing this week. Abnormal dryness and drought are currently affecting over 112 million people across the United States including Puerto Rico—about 36.0% of the population.