Strong El Niño conditions, with sea-surface temperature anomalies on track to set records through fall 2026, represent the dominant driver shaping first measurable snow (≥0.1 inch) timing across the U.S. NOAA outlooks favor milder temperatures and altered jet stream patterns that typically delay accumulating snow in the northern Plains, Upper Midwest, and Northeast relative to climatology, while boosting moisture in the southern tier. Recent model consensus and observations show early-season snow possible at high elevations in the northern Rockies and parts of the interior West this mid-October due to a cold front interacting with tropical moisture, consistent with typical October windows for those sites. Traders should monitor updated NWS and ECMWF runs for landfall or cold-air intrusion timing, plus official first-snow reports from major stations, as these will refine implied probabilities ahead of November resolution thresholds.