Disclosed is an improved implementation of a flood fill mesh radio network that utilizes probability forwarding for rebroadcasting network messages. The forwarding probability may be determined based on analyzing a neighbor topology map constructed by each network node relative to its neighbor nodes on the network and derived from state information supplied in synchronization frames. The forwarding probability may comprise a statistical probability that a message frame received by a network node will be forwarded to the intended destination network node by one or more of the network node's neighbor network nodes. The forwarding probability may also be based on constructing a heat map of hot nodes that are identified as those originating nodes in originating node/forwarding node pairs that are the first to forward message frames along paths in the network relative to duplicate message frames received from different originating/forwarding node pairs along different paths.