Broadband satellite-based IP networks have been considered as the technology to enable a strong and promising next-generation market. In satellite communication systems, the channel performance might be severely degraded due to the dynamic weather conditions such as the precipitation, and thereby lead to network congestion. Therefore, congestion control is critical in such networks to satisfy QoS based Service Level Agreement (SLA). Moreover, the inherent large bandwidth-delay product of satellite channels impedes the deployment of existing numerous congestion control schemes. In this paper, we propose a modified Random Early Detection (RED) based congestion avoidance/control mechanism that incorporates a fuzzy logical controller to tune the queue thresholds of RED according to the dynamic weather conditions. We will show using analysis and simulations that the newly developed congestion control method is effective and efficient for broadband satellitebased IP networks.