The highest temperature in London on April 28 will definitively exceed 14°C. ECMWF operational 00z run, in lockstep with the GFS 12z ensemble mean, pegs central London (LHR observation points) at 16.0°C and 15.8°C respectively, with GFS 75th percentile at 17.1°C. The synoptic pattern shows a robust mid-level ridge consolidating across SE England, driving strong diurnal heating under increasing insolation post-frontal clearance. 850mb temperatures are projected to climb to +7°C by 1500UTC, a significant thermal advection for late April. Boundary layer mixing depths are favorable, further aided by the localized Urban Heat Island effect, adding an estimated 1.5°C to metro observation points. Model output probability density functions show an overwhelmingly positive skew towards the "yes" outcome. This isn't a tight call; the meteorological drivers are firmly in place. 90% YES — invalid if the 06z UKMO run introduces a significant stratocumulus shield with persistent low-level moisture.
The highest temperature in London on April 28 will definitively exceed 14°C. ECMWF operational 00z run, in lockstep with the GFS 12z ensemble mean, pegs central London (LHR observation points) at 16.0°C and 15.8°C respectively, with GFS 75th percentile at 17.1°C. The synoptic pattern shows a robust mid-level ridge consolidating across SE England, driving strong diurnal heating under increasing insolation post-frontal clearance. 850mb temperatures are projected to climb to +7°C by 1500UTC, a significant thermal advection for late April. Boundary layer mixing depths are favorable, further aided by the localized Urban Heat Island effect, adding an estimated 1.5°C to metro observation points. Model output probability density functions show an overwhelmingly positive skew towards the "yes" outcome. This isn't a tight call; the meteorological drivers are firmly in place. 90% YES — invalid if the 06z UKMO run introduces a significant stratocumulus shield with persistent low-level moisture.
