Seasonal Weather Outlook — May 25, 2026

Seasonal Weather Outlook — May 25, 2026 El Nino is emerging fast, with C3S multi-system ensembles now pushing above +2.5C in Nino3.4 by late 2026, reshaping global energy demand patterns from European gas storage through Asian monsoon timing. ENSO & Teleconnections ENSO-neutral conditions persist but transition is underway. The Nino3.4 weekly SST hit +1.1C, while the ONI remains +0.1 based on the three-month running mean through March. Subsurface temperatures have risen for six consecutive months. NOAA CPC assigns 82% probability of El Nino by May-July, rising to 96% by Dec-Feb 2027. Peak strength uncertain — no single category exceeds 37% — but the ECMWF C3S multi-system is aggressive, with over half of ensemble members exceeding +2.5C amplitude. The MJO is active in Phase 3 at amplitude 1.5, supporting enhanced convection over the eastern Indian Ocean. QBO at 50 hPa is easterly at -1.5 m/s. Easterly QBO plus developing El Nino historically favours milder European winters — bearish for TTF winter contracts if the pattern holds. NAO GEFS 16-day forecast oscillates near zero, drifting slightly negative. The AO is more notable: rising from +0.61 to +1.89 over the forecast period. Strongly positive AO suppresses cold air outbreaks — bearish for heating gas demand into early June. 6-Week Temperature Trajectory EC46 shows a clear pattern for NW Europe: warm week 1, sharp week 2 cooldown, gradual recovery weeks 3-6. London drops from 20.6C (18.7-22.9) to 15.7C (12.7-18.7) in week 2 — a 4.9C decline with the ensemble spread doubling. Frankfurt's week 2 spread is widest at 9.2C (13.6-22.8), reflecting genuine model disagreement. The 00Z EC46 changes amplify both extremes: Amsterdam May 30 revised +4.2C warmer, Paris May 30 +3.3C. But Frankfurt June 5 dropped -3.6C, London June 5 down -3.3C, Paris June 5-6 both down over 3C. Week 1 warmth getting warmer, week 2 cooldown getting cooler. East Asia shows steady warming: Seoul 20.9C to 24.3C over six weeks with narrow spreads. Tokyo 22.1C to 25.8C. CDD implications grow through June-July. Houston ramps from 25.1C to 29.2C — consistent US summer build. Regional Seasonal Outlooks ECMWF C3S predicts above-average European summer temps in all regions, highest confidence in southeastern Europe. Northern Europe expected to see anomalously high SLP — blocking patterns that could reduce wind generation. Eastern Europe flagged for below-average precipitation, bearish for hydro. NOAA CPC US outlook favours above-normal temps over western CONUS and Great Plains through June, with 70%+ probability in Pacific Northwest. Bullish for Henry Hub summer CDDs if sustained. JMA shows rainy season onset for Japan with precipitation probabilities rising to 70% across northern Honshu by May 28-29. Mumbai's steady decline from 30.9C to 26.9C signals Indian monsoon onset with high confidence. Hydro & Storage EU gas storage at 37.5%, well below 50% seasonal norm. Injection rate of +0.28%/day implies ~100 days to reach 90%. Equinor warns storage cannot survive three more months of Hormuz disruption. Warm week 1 helps — minimal HDD allows unimpeded injection. Strategic Positioning - ICE Endex TTF winter strip: El Nino + positive AO = bearish heating demand. But 37.5% storage deficit constrains downside. Net flat to cautiously bearish, Hormuz resolution as primary catalyst. - Platts JKM front-month: Monsoon onset suppresses near-term Asian cooling demand. Coal-to-gas reversal structurally bearish for LNG spot. Watch $17.11 support. - NYMEX Henry Hub summer strip: CPC warm outlook bullish for CDDs. MM net short -96,289 lots creates short-covering fuel. - German baseload power front-month: Week 1 warmth + low wind = elevated. But 00Z wind uplift from May 31 could compress prices entering June. - European carbon (EUA): Weak eastern European precipitation + week 2 temp drop could increase thermal generation. Modestly supportive. - Newcastle coal: Sydney drops to 10.9C by week 6 as winter deepens. Heating demand ramp bullish into June-July.