Daniel Swain on the next wave of Four Corners storms expected this weekend (Halloween 2026):

The fact that this pair of back-to-back extreme-to-record shattering rain events across the interior Southwest have occurred during the autumn during (one of the) strongest El Niño events on record is not a coincidence! Such events are known to be amplifed by 1) unusually warm ocean waters in the eastern subtropical Pacific, 2) increased East Pacific tropical cyclone activity, and 3) a strengthened early-season subtropical jet in this region–all of which are much more likely to occur under strong El Niño conditions. We also know that climate change has warmed both the atmosphere and oceans–raising the ceiling on how much moisture can be in the air when it is saturated, as in a storm cloud, and thus also the ceiling on extreme precipitation intensity. When natural climate cycles (e.g., El Niño) align with the effects of long-term human-caused warming (i.e., climate change), this is precisely when we should expect to see an increased possibility of historically unprecedented hydroclimate extremes.