Hovmollers

The hovmollers presented here are based on ECMWF ensemble forecasts (J1-J45). They make it possible to follow the evolution of equatorial waves through observations and forecasts. The filtering methodology is described in the filtering tab.

LThe graphs on this page show the coloured PW and wind anomalies at 850 hPa obtained from the difference between the mean of the 51 members of the ECMWF ensemble forecast and the hindcast (11 members). The superimposed contours show the contribution of equatorial waves to these anomalies in phases favourable to convection only.

For PW, wet contributions (PW*>0) are outlined.

For the zonal wind, the westerly anomalies are shown in red. The westerly wind contributions associated with the waves are shown as contours.

For meridional winds, southerly wind anomalies are shown in red. The favourable contribution to convection depends on the hemisphere considered. We have therefore outlined the southerly anomalies associated with waves in the northern hemisphere (West Africa in particular) and indicated the northerly anomalies associated with waves in the southern hemisphere.