CICS-NC: MJO monitoring v2

Register  |  Archive  |  RMM (v1)  |  Extratropics (v1)

Wheeler and Weickmann (2001) developed a method for filtering OLR in real-time to identify, track, and predict the MJO and equatorial waves. This webpage expands on their methodology and applies it to other variables.

• Original:

  • Very similar to the original Wheeler-Weickmann method. One notable difference is that the zonal mean wave variance is maintained constant in the projections. This helps maintain realistic wave amplitudes.

• No TCs:

  • Tropical-cyclone-related anomalies are removed before filtering following the method of Schreck et al. (2011) and Aiyyer et al. (2012)

• CFS Forecasts:

  • Instead of appending with climatology as in Wheeler-Weickmann, the observations are instead padded with 45-day forecast anomalies from the CFS. These anomalies are the mean of a 16-member pseudo-ensemble including all four runs each from 00z, 06z, 12z, and 18z yesterday.

These Hovmöllers show longitude-time plots for OLR, zonal wind (uwnd850 & uwnd200), meridional wind (vwnd850 & vwnd200), velocity potential (chi850 & chi200), and streamfunction (psi850 & psi200) at 850-hPa and 200-hPa.

Shading shows anomalies from climatogy in the past. In the future, shading is either the sum of all modes or the CFS forecast and its departure from its own climatology. Contours identify the MJO, equatorial Rossby waves, Kelvin waves, and the low-frequency background (> 120 days). Hurricane symbols denote tropical cyclogenesis identified by NHC and JTWC, with the direction indicating Northern or Southern Hemisphere.

OLR data used here are NOAA's interim Climate Data Record as obtained from Univ. of Maryland. Tropical cyclone data are obtained from NHC and JTWC through NCEP's tcvitals data. All other fields are obtained from CFS analyses.