Nov 1, 1993

Frequency of Heavy Rainfall Events in New Orleans, Louisiana, 1900 to 1991

Barry D. Keim, Robert A. Muller
Southeastern Geographer
  • States that the large number of recent heavy rainfall events in New Orleans, Louisiana, has raised concerns about change in the heavy rainfall climatology in the area
  • Finds that "recent" (study was published in 1993) magnitudes of New Orleans storms were significantly larger than storms over the preceding 100 years and heavy rainfall events appear to be increasing in frequency
  • Examines all rainfall events exceeding 125 mm (4.6 inches) with respect to their generating mechanisms, seasonality, and changing frequencies through time
  • Finds that two thirds of the storms were induced by frontal weather situations and tropical systems produced about a fourth
  • Finds that storm seasonality was bimodal with peaks in late spring and early fall
  • Finds that with regard to changing frequencies through time, the entire New Orleans rainfall record suggests that storms may have a pattern of increasing occurrence