Flash Flood — Richland, Louisiana

2006-10-16 to 2006-10-17 · near Archibald, Richland, Louisiana

Event narrative

Tremendous amounts of rain fell across Richland Parish during the afternoon and evening of October 16th. Eight to fifteen inches of rain fell during this time causing significant flooding across the parish. Dozens of homes were flooded along with a large majority of the roads across the parish. Many roads had sections washed out and were impassable. Locals who have lived in the area all their life mentioned they have never seen water like that before.

Wider weather episode

A significant heavy rain and flash flooding event occurred on October 16 and into the first part of October 17. The event was set up by an anomalous pool of tropical type moisture (300% of normal) over the western Gulf of Mexico which was then pulled northward by strong low level winds in advance of a westward moving upper level disturbance. There were several other factors in play which contributed to the large amounts of rain, such as a northward moving warm front and a building upper ridge over the eastern Gulf of Mexico. The warm front helped lift the air while the building upper ridge served to weaken the westward moving upper disturbance. This then caused the progression of the heavy convective rains to slow and dump tremendous amounts of rain from southeast Texas to north and central Louisiana and then into west-central Mississippi. By late evening, dry mid level air began pushing east from Texas and allowed the heavy rain shield to move and exit the region by early Tuesday morning. Heavy rains were not the only weather type during this event, a couple of tornadoes occurred along with scattered reports of wind damage.

What makes this event rare is that such a large area received 6 to 10 inches of rain and an even larger area received 4 to 6 inches. Embedded in that swath, a few locations in northern and central Louisiana received a whopping 12 to 17 inches! During this time of year, these kinds of rains usually occur from slow moving tropical cyclones, not from a warm front and westward moving upper disturbance. The result of all this rain was numerous reports of flash flooding, some even significant, across northeast Louisiana and west-central Mississippi. This event will go down in the record books for the amount of real estate covered by heavy rainfall and the several locations that measured extreme amounts.

View location on OpenStreetMap → (32.2000, -91.9600)

Source: NOAA Storm Events Database, event_id 1505. Narrative written by the NWS forecast office that issued the report.