Here is a map depicting the total amount of precipitation that was received in the Billings County Warning Area for the entire month of May.
May 2011 was an historically wet month across our region. Billings and Miles City each observed their wettest
month on record, and flooding problems were widespread and persisted for weeks. Several factors came together to
bring us a prolonged period of wet weather, which began about a week into May. High pressure in northwestern
North America allowed for the storm track to remain over the central and southern Rockies. A series of slow-moving
storms tapped into Gulf of Mexico moisture as they moved into the plains, as they often do in late spring.
East winds added to the strength of the storm systems as well. Certainly, one or two of these wet systems are not
uncommon during the month of May, but the stagnant weather pattern of 2011 allowed for several very wet systems to
impact our region. The recent wet weather will keep the grasses green and the ground moisture high for awhile,
which will help fuel thunderstorm activity into the summer, but otherwise it will not have much of an impact on
our weather by late summer into fall.