Could the Drought Affect Severe Weather this Fall?

The few storms that rolled through Thursday served as a good reminder that autumn often brings a second severe weather season, particularly to the Gulf States. October is usually the beginning of this season, averaging 5 tornadoes per year, over a 25 year period. November is the height of the season, averaging 6 tornadoes per year. That doesn’t mean severe weather strikes every year; it’s more realistic to say that some years we see little to no activity and other years we see outbreaks during the fall which give us these numbers.

mapbuild_1

Average number of tornadoes during November, based on a 25 year period.

You’ve no doubt noticed that this fall has been less than active. In fact, we’ve spent this fall sinking deeper into drought. That doesn’t mean that a strong storm system still couldn’t come through. We spoke to Alabama State Climatologist Dr. John Christy to see if the drought could affect our chances of severe weather in the coming weeks.

He explained that there are only minor correlations between severe weather and drought in general. There is, however, a slightly greater tendency towards severe weather during La Nina years. Right now we’re in a neutral ENSO pattern, but a La Nina watch is out. One severe weather risk Dr. Christy outlined during drought though is flooding:

“Dry ground with dormant vegetation tends to absorb less moisture in the
first hour or so of a heavy rain, so that runoff actually can be higher
in a storm event – creating more chances for flooding situations if a
relative sudden downpour occurs.”

He also says that during winters under a weak La Nina there tends to be a higher tendency for arctic air outbreaks.

Keep in mind that you should always be prepared for severe weather. Check the forecast regularly for storm chances and be sure to download the Live Alert 19 app!