U.S. Department of Commerce


Date of this Version



Science and Technology Infusion Climate Bulletin NOAA’s National Weather Service 33rd NOAA Annual Climate Diagnostics and Prediction Workshop Lincoln, NE, 20-24 October 2008


U.S. Government Work


The El Niño-Southern Oscillation (ENSO) is known to affect synoptic patterns across the continental United States, particularly by its impact on the upper tropospheric jet stream position. Global circulation patterns influence synoptic weather patterns by impacting the location of mid-tropospheric ridge and trough locations and thus areas favorable for temperature and precipitation anomalies, which in turn influence regional severe weather activity. Though it is one of several factors associated with the potential for severe weather, the synoptic environment plays a key role in severe weather potential by providing favorable ingredients for the development of severe convection (e.g. Miller 1967). While ENSO is one of many factors that influence global circulations, and by distillation may have a less distinguishable influence on the synoptic pattern, coherent signals can be uncovered in the synoptic environment, based on ENSO phase, that would influence the potential for severe convection in the north central United States. Seasonal predictions of severe weather potential are not much aid for daily operations, but they can be used by emergency managers, the media, and forecasters to increase preparedness for seasons that have the potential for above normal convective activity.