Fig. 3: Composite anomaly maps for Ural Blocking events under strong and weak positive AO regimes at selected lag times.

Each panel shows detrended 2-m temperature anomalies (shading, °C), 500-hPa geopotential height anomalies (contours, gpm), and wave activity flux (vectors, m2·s−2) for UB events under (left) SPAO and (right) WPAO at: a, b Lag −3 days, c, d onset date, e, f Lag +4 days, and g, h Lag +8 days. White dots indicate temperature anomalies statistically significant at the 95% confidence level based on a two-tailed Student's t test.