WEEKLY Weather FORECAST

This is a contour map of weekly average sea level pressure and anomalies for Africa with respect to the 1981-2010 climatology.

The Weekly mean position of ITD, CAB and ITCZ and their maximum and minimum displacements, respectively

This is a contour map of monthly Relative Humidity and anomalies at 700 hPa for Africa with respect to the 1981-2010 climatology.

The geopotential height of the 500 hPa pressure surface shows approximately how far one has to go up in the atmosphere before the pressure drops to 500 hPa (i.e. 500 millibars). On average this level is around 5.5 km above sea level, and it is often referred to as a steering level, because the weather systems beneath, near to the Earth's surface, roughly move in the same direction as the winds at the 500 hPa level. Height contours are labelled in tens of metres (=decametres, ="dam") with an interval of 4 dam. The contours effectively show the main tropospheric waves that "control" our weather - low heights indicate troughs and cyclones in the middle troposphere whilst high heights indicate ridges and anticyclones.

This is a contour map of weekly relative humidity and anomalies at 850 hPa for Africa with respect to the 1981-2010 climatology.

The Madden-Julian Oscillation (MJO) is the major fluctuation in tropical weather on weekly to monthly timescales. The MJO can be characterised as an eastward moving 'pulse' of cloud and rainfall near the equator that typically recurs every 30 to 60 days.

 The weekly wind anomaly vectors and Weekly DIvirgence anomaly are computed separately. Vectors show the resultant wind anomaly direction, and the vector length indicates the magnitude of the resultant wind anomaly.

This product shows wind direction and anomaly at 700 and 850 hPa level. This makes it possible to examine the intensity of the West African monsoon at different levels.

This product shows wind speed and anomaly at 200 hPa level. It shows the position of Tropical EasterlyJet and Subtropical Jet

Total precipitation in percentage of average is based on the formula: P(%)= Total current precipitation/long term (1981-2010) average of precipitation X 100

Precipitation forecast based on analysis of Weekly observed precipitation , Weekly precipitation climatology,MJO observed and forecasted, Precipitable water forecast, Zonal wind, Wind anomalies forecast, Divergence, Weekly NCEP/GFS Ensemble Forecasts precipitation and NAO (see practical guide).

The climate outlook for soil moisture shows the current analysis and the forecasted change over the next 8 days.