Long-range ensemble mean for Helsinki on April 28 indicates a positive thermal anomaly. GFS/ECMWF guidance projects a developing anticyclonic ridge over Fennoscandia, favoring dry continental air advection and strong diurnal warming. While the climatological mean is ~9°C, sustained solar insolation under stable conditions pushes the median forecast high to 13-14°C. Model probabilities of exceeding 12°C are >65%. 80% YES — invalid if a persistent maritime cyclonic influence establishes before April 27.
Long-range ensemble mean for Helsinki on April 28 indicates a positive thermal anomaly. GFS/ECMWF guidance projects a developing anticyclonic ridge over Fennoscandia, favoring dry continental air advection and strong diurnal warming. While the climatological mean is ~9°C, sustained solar insolation under stable conditions pushes the median forecast high to 13-14°C. Model probabilities of exceeding 12°C are >65%. 80% YES — invalid if a persistent maritime cyclonic influence establishes before April 27.
