ST. LOUIS (AP) — The latest U.S. Drought Monitor survey shows an increase in extreme drought conditions in four Plains states but a slight decrease in the overall area of the lower 48 states experiencing some form of drought. The map posted Thursday on the monitor’s website shows that nearly two-thirds of the lower 48 states is experiencing some drought. Recent rainfall pushed the percentage down to 62.91, from last week’s 63.86. The report says one-fifth of the U.S. is experiencing extreme drought. That number ticked up nearly 2 percentage points to 22.3 percent, largely because of worsening conditions in parts of Nebraska, Kansas, Missouri, and Oklahoma.