New Mexico Geological Society Annual Spring Meeting — Abstracts

This project is an observational investigation of the wettest year on record in New Mexico, the year 1941. Many different variables and climatic indices are examined, including the Palmer Drought Severity Index (PDSI), monthly precipitation statistics, temperature, monsoon rainfall, sea surface temperature (SST) anomalies, weather map analysis, tropical storm remnants, synoptic-scale composites, analysis of individual conditions that produce certain storm events, and external factors such as El Niño-Southern Oscillation indices over various spatial and temporal extents. In particular, extensive use is made of a new large-scale data set generated from a 20th Century “reanalysis”. The reanalysis uses historical surface data that is assimilated by a modern atmospheric general circulation model with a consistent analysis scheme, essentially using the model to carry out a three-dimensional dynamical interpolation of sparse data using just surface weather data to anchor the analysis. The reanalysis product yields reconstructed three-dimensional weather information for an era in which there are no direct upper air measurements. The overall goal of this project is to explore why the year 1941 was so abnormal for the state of New Mexico in terms of precipitation, allowing me to assess whether these conditions are likely to occur again. It was found that a combination of the highest Pacific Decadal Oscillation (PDO) value with a moderate El Niño led to large precipitation anomalies region-wide that are consistent with an El Niño event. In conclusion, a widespread precipitation anomaly like the one that occurred in 1941 is a low-probability event based on the severity, area, and duration of the precipitation anomaly that was generated.