In response to the extreme rainfall at Cherapunjee, severe flash floods have been observed in the North Eastern region of Bangladesh. The observed and the forecasted water level by the BWDB of 3- and 5-day lead time-based forecast are illustrated in Figure 4. The anomalies between the observed and the forecasted water level by the BWDB are compared in order to assess the accuracy of the forecasts. The water level of the stations observed in the upstream of the NE region of Bangladesh (Lourergarh, Sylhet, Sheola, and Sherpur) is underestimated by the 3 days and 5 days  forecast just after the extreme rainfall on 15 June, and the difference is significant after 16 June, just after the extreme rainfall on Meghalaya. During the extreme event time (16-20 Jun) at Laurergarh (Jadukata-Rakti River) the maximum anomalies of 3 days and 5 days forecast was 1.51 m and 1.4 m respectively. In the case of Sylhet (Surma river), they were 1.34 m and 1.74 m for 3 days and 5 days  lead time, respectively. The maximum anomalies at Sheola (Kushiyara) were 1.43 m and 2.22 m for the above-mentioned lead times.