El Nino's most reliable hydrological fingerprint is not in the Atlantic, it is over the Panama isthmus. The canal is not a sea level cut, it is a staircase of locks fed entirely by rainfall into Gatun and Alhajuela lakes, and every transit spends roughly 50 million gallons of fresh water that has to be replaced from the sky. The three most recent strong El Nino events, 1997/98, 2015/16 and 2023/24, each produced draft cuts and transit rationing in the following January to April dry season. The 2026 event is behaving like a strong one: it has suppressed Atlantic hurricane formation while driving an unusually violent East Pacific season, which is exactly the atmospheric signature that precedes a dry Panamanian dry season.
The second link is the one most readers miss: rationing is not applied evenly, it is auctioned, and gas carriers lose the auction. The Panama Canal Authority allocates scarce slots through booking and a bidding system. A container line runs a scheduled service, holds long term slot allocations and can spread a seven figure slot cost across more than ten thousand boxes, so it pays and keeps its rotation. A VLGC carrying roughly 44,000 tonnes of propane cannot. In November 2023 an LPG carrier did pay $3.975m for one transit, still the record, and the rest of the segment drew the obvious conclusion and stopped bidding. Gas carriers are the marginal, price taking user of the canal, so they are the first cargo class physically pushed out.