This Hurricane Surge Hazard Primer summarizes important basic technical information about surge phenomena, hazard, and risk. It provides an overview of surge hazard analysis, including uncertainty in surge hazard estimates. Importantly, this Primer describes the limitations of hurricane surge hazard analysis and risk management under the National Flood Insurance Program. The reader is encouraged to refer to other reports listed in the References for a more detailed explanation of many key concepts.
This is a more technical account of the specific issues of surge in the Pontchartrain basin:
Analysis of time-lapse dynamics of recently simulated major storm surges and historical storm surge maximum observations shed new light on spatial and temporal patterns of storm surge within the Lakes Pontchartrain and Maurepas region (PMSC region, see Figure 1). While the terms tilting or sloshing have been previously used to describe key dynamic processes of storm surge movement in Lake Pontchartrain, these terms can be misleading because the peak surge generally rotates around the lake perimeter (“surge rotation”) rather than directly transferring (tilting/sloshing) from one end of the lake to the other.
In this analysis, two recent storms are examined as archetypical events that exemplify a new conceptual model that we introduce. Hurricanes Katrina (2005) and Isaac (2012) had fundamentally different tracks which seem to illustrate well the contrasting patterns of storm surge rotation introduced here. However, while these exemplify a generalized surge rotation model, it is important to keep in mind that our conceptual model is built around local forcing on storm surge and not the larger coastal processes. Every storm is different and the resulting surge is always a result of regional and local forcing. The limitation of this study is that we only discuss the movement of surge within the PMSC region and not the dynamics of surge entering into the PMSC region by more regional meteorological or coastal processes. In spite of this limitation, much can be said about the generalized relative movement of maximum surge in the PMSC region