Anomalous Early Onset of Spring Across North America

During the month of March 2012, an amplifying upper level ridge over the central United States became the catalyst for unseasonable warmth as 15,272 warm temperature records were broken and subsequently led to the warmest March since records began in 1895 across the contiguous United States. Normal to below normal temperatures later returned in April producing frosts and freezes across northern portions of the United States and delivered significant economic losses to the agricultural and ecological sectors. Changes in the start of the growing season during spring are a source of significant uncertainty in modeling the Earth's climate system.

Utilizing the Spring Indices (SI-x) model derived by Dr. Mark D. Schwartz, this study analyzes synoptic and teleconnection patterns responsible for anomalously early springs across North America as simulated by a 1°x1° control run of the Community Earth System Model (CESM). Understanding and identifying the large-scale synoptic wavelengths responsible for early springs, such as March 2012, may allow atmospheric scientists to identify patterns responsible for the unusual warmth in a changing climate. Future work for this project will evaluate the regional short and long-term temporal trends in the onset of spring according to the standard SI-x metrics.