Excessive rain soaks central Louisiana again.
For the third time in a month, portions of central Louisiana were inundated with excessive rainfall. Recall these dates: April 2-3; April 30; and May 3-4. Each of these episodes brought a round of severe weather and flooding rains.
All three of these situations shared some meteorological factors that are known to cause severe weather and heavy rain in the Deep South and Gulf Coast. An active jet stream with a major disturbance gets the air on the move. This causes warm, moist air from the Gulf and cooler, drier air from the Rockies/Plains to mix. The leading edge of these moving bodies of air (air masses) is termed a front. Added to this was the copious amount of moisture through a deep layer of the atmosphere. This unusual amount of moisture, some 200% of normal, can be traced at least partially to high than average near-shore water temperatures in the Gulf. When these air masses mix, the battle creates storms, clouds, and rain.
As you know, rainfall amounts vary greatly over short distances. The totals you see on the graphic do not tell the whole story. Between these plotted values are other locations where more rain fell. For example, Ragley in Beauregard Parish measured 7.46 inches. This is about a 10-year amount.
The best news is that a different weather pattern will dominate the forecast for a while. A strong ridge of high pressure will develop over the center of the United States and take the active jet stream on a path away from central Louisiana. Also, drier air will rule as well.