ECMWF ensemble means project Tokyo's peak temperature at 22-23°C, but a robust upper-level ridge development over Honshu by April 28 is undeniable. This synoptic pattern ensures strong subsidence warming and amplified insolation, driving thermal advection. While the deterministic ECMWF run is slightly below, a compelling 35% of its ensemble members and several high-resolution GFS runs explicitly breach 24°C. The current market is severely underpricing this late-season boundary layer warming potential. 75% YES — invalid if subsequent ECMWF runs shift ridge axis significantly east or introduce a strong cold front.
ECMWF ensemble means project Tokyo's peak temperature at 22-23°C, but a robust upper-level ridge development over Honshu by April 28 is undeniable. This synoptic pattern ensures strong subsidence warming and amplified insolation, driving thermal advection. While the deterministic ECMWF run is slightly below, a compelling 35% of its ensemble members and several high-resolution GFS runs explicitly breach 24°C. The current market is severely underpricing this late-season boundary layer warming potential. 75% YES — invalid if subsequent ECMWF runs shift ridge axis significantly east or introduce a strong cold front.
