Study: Droughts Can Travel Like a Slow-Moving Hurricane.
Depending on the continent, some droughts move 800 to 1,900 miles from what researchers are calling hotspots.
From that data, the researchers located as many as four hotspots from each continent.
In North America, on average it takes 16 months for a drought to migrate 500 miles.
In North America, hotspots do not seem to favor a particular region of the continent, but droughts do typically move toward the north from the southwestern United States.
Movement of the droughts is erratic on most continents, except in Australia where drought tends to travel toward the north.
Since there is less water to evaporate from a drought-stricken area, there is less water available to fall out as rain or snow downwind.
In the first scenario, a ridge or dome of high pressure may move slightly from region to region over time while creating dry conditions underneath it.
In the second scenario, the weather patterns that result from El Niño often breed areas of drier conditions in some parts of the globe.
In the United States, the Ohio Valley is often a location where drier than average conditions set up.