Adam J. Stepanek, Capt, USAF Co-Advisors: Tom Murphree, Ph.D., & Carlyle Wash, Ph.D.

1. North Pacific – North American Circulation and Precipitation Anomalies Associated with the Madden-Julian Oscillation • Overview: • DoD knowledge of interannual phenomena such as the MJO is minimal, but is a major topic in meteorological research. • Current studies highlight teleconnections from MJO to NPNA but are incomplete. Further research is necessary in order to enhance the ability to base medium and long range forecasts on the MJO. • Hypotheses: • MJO teleconnections to the NPNA region are sensitive to a variety of critical factors, especially phase, amplitude, season of MJO occurrence, and concurrent El Nino/La Nina conditions. • Knowledge of these factors will lead to improved extended-range forecasts of NPNA circulation and precipitation. Adam J. Stepanek, Capt, USAF Co-Advisors: Tom Murphree, Ph.D., & Carlyle Wash, Ph.D. Naval Postgraduate School - March 16, 2006

2. All Months, All Amplitudes (1.00+), All EN/LN/N, No Lag Categorize by EN, LN and N Change Phase Only Change Amplitude Only Change Season Only Identify Critical Factors and their NPNA Impacts – Benchmark Results Z200 Anomaly OLR Anomaly Precip Rate Anomaly Key Method – Composite According to Critical Factors

3. Composite of 5 Wettest Periods in CA Composite of 5 Driest Periods in CA Comparison of Driest and Wettest Composites - CA • Composites based on MJO and wet (dry) conditions in CA-DSW show clear EN (LN) patterns in tropical and northeast Pacific. • Onshore/offshore flow anomalies a major contributor to western CONUS precip anomalies.

4. MJO - NPNA teleconnections are very complex. • Highly dependent on phase, season, and concurrent El Nino and La Nina conditions (less sensitive to MJO amplitude) • Have enhanced scientific basis for extended range NPNA forecasting and developed preliminary forecasting rules-of-thumb Key Results of Research • Favorable (F) and unfavorable (U) conditions during MJO activity for fall-winter: • Positive precipitation anomalies in CA-DSW: F: Early and late phases of MJO F: Presence of neutral conditions in OND F: Presence of El Nino during JFM F: Anomalous wave train from Asia with low over northeast Pacific F: SW-NE tilt to anomalous low-high dipole over northeast Pacific U: Middle phases of MJO U: Presence of LN • Negative precipitation anomalies in CA-DSW: F: Middle and late phases of MJO F: Presence of La Nina F: Anomalous high over northeast Pacific F: SW-NE tilt to anomalous high-low dipole over northeast Pacific U: Early phases of MJO