Atlantic-Modulated UK Warm-Summer Cycle Hypothesis: Stage 1

This Stage 1 publication presents the Atlantic-Modulated UK Warm-Summer Cycle Hypothesis, which proposes that clusters of unusually warm UK summers may exhibit a quasi-periodic multidecadal recurrence centred approximately on a 50-year timescale. An apparent historical sequence is proposed around 1726, 1776, 1826, 1876, 1926, 1976 and 2026. The sequence is treated as a set of nominal cycle centres to be tested, not as proof of an exact 50-year climatic clock. The proposed mechanism places North Atlantic sea-surface temperature (SST) variability and recurring atmospheric circulation configurations at the centre of the hypothesis. Possible solar-cycle modulation is retained as a secondary, provisional mechanism requiring independent testing. Existing research supports the broader proposition that North Atlantic SST variability can influence European summer climate, but it does not by itself validate the specific approximately 50-year recurrence proposed here (Sutton & Hodson, 2005; Sutton & Dong, 2012). Stage 1 defines the hypothesis, terminology, evidence framework, proposed mechanisms, data sources and falsifiable predictions. It does not claim statistical validation. Stage 2 will test the apparent periodicity using objective cluster detection, detrending, cycle-length comparison, significance testing, mechanism analysis and out-of-sample validation.