La Nina Gains Strength, Strongest Signature of Late 2025 So Far
12/23/2025, 8:23 am EST
Equatorial Pacific Ocean Subsurface Heat Warming; La Nina Likely to End Early 2026
12/29/2025, 11:54 am EST
Climate Impact Company Daily Feature
Issued: Friday, December 26, 2025
Highlight: Climate drivers in the extended-range (11-15-day) forecast…MJO weak, stratosphere rules.
Discussion: Climate drivers in the 11-15-day extended-range forecast indicate the Madden Julian oscillation (MJO) is weak therefore tropical forcing is weak (Fig. 1). The stratosphere is shifting much colder following the NOV/DEC warm event as indicated by the 40-day CFS V2 projection (Fig. 2). The core of the colder stratosphere is in the same location as the NOV/DEC warming event, across northwestern North America (Fig. 3). However, regional (stratospheric) warming is projected across Europe which sustains a cold Europe pattern in the 11-15-day period as indicated by AI Graph Cast (Fig. 4). Below normal snow cover across Europe (Fig. 5) finally shifts by 10 days according to GFS as Central and East Europe gain snow cover helping to sustain the cold (Fig. 6).
Fig. 1-2: ECMWF 30-day MJO forecast and CFS V2 4-day upper atmosphere temperature anomaly outlook.
Fig. 3-4: The ECM ENS 11-15-day 10 MB temperature anomaly forecast and AI Graph Cast 11-15-day temperature anomaly outlook for Europe.
Fig. 5-6: The daily snow cover anomalies analysis from the Rutgers Snow Lab and GFS day-10 snow depth projection.