US drought migration patterns are not what I expected

We also note that migrants are very strongly attracted to areas experiencing drought. Drought are associated with low precipitation and higher-than-average temperatures, two amenities that attract residents (even if they may be detrimental for local agriculture).

That is from The Effect of Natural Disasters on Economic Activity in US Counties: A Century of Data, an NBER paper looking at 90 years of county data from the United States by Leah Platt Boustan, Matthew E. Kahn, Paul W. Rhode, Maria Lucia Yanguas.

In general hurricanes, forest fires, and landslides encourage people to leave. “On the other hand, and surprisingly,” they write, “tornados and earthquakes appear to have no effect on mobility flows.” Floods actually cause in-migration, perhaps because infrastructure improvements in response to flooding (dams, levees, and the like) create more buildable land.

But droughts?