In common with the anomalies found in other regions around Lake Victoria's proximity, the time series plot for this area's precipitation anomalies show huge (> 1σ) positive anomalies during the latter part of the 20th century. The 1960s were particularly very wet. The models give an indication for continued wet conditions in this area during the 21st century.
The time series plots show that the long-rains fell in abundance during much of the 20th century. The variability during this season is apparently lower as evidenced by the low (compared to short-rains) amplitudes of the anomalies. Towards the close of last century, the long rains were apparently erroneous. The models give an indication for a reversal of the subtle negative anomalies from the early decades of the 21st century. However, the signal-to-noise ratio in the model projections for this season's precipitation is comparatively low.
With very few exceptions, the models show a clear wet bias with regard to their 20th century annual cycle. Notwithstanding, they correctly locate the peaks of the rainfall seasons. The MRI CGCM2.3.2 is remarkably too wet. All models project an increase in mean monthly precipitation in this area, an exception being the HadGEM1.