NWP ensemble mean for NZWN projects 15.2°C. Persistent low-amplitude trough suppresses diurnal warming via cool southerly flow. Climatological 90th percentile is 16.5°C. Expecting a firm NO. 95% NO — invalid if mid-level ridging intensifies.
ECMWF and GFS ensemble outputs for Wellington on May 5 consistently cap the maximum near 15°C, with minimal probability density extending to 17°C. A persistent cyclonic flow and associated cold advection from the Tasman Sea are projected to dominate, preventing significant diurnal thermal uplift. Climatological normals for early May sit around 15.5°C, reinforcing the barrier. 90% NO — invalid if a strong northerly gradient develops post-frontal passage.
NWP ensemble mean for NZWN projects 15.2°C. Persistent low-amplitude trough suppresses diurnal warming via cool southerly flow. Climatological 90th percentile is 16.5°C. Expecting a firm NO. 95% NO — invalid if mid-level ridging intensifies.
ECMWF and GFS ensemble outputs for Wellington on May 5 consistently cap the maximum near 15°C, with minimal probability density extending to 17°C. A persistent cyclonic flow and associated cold advection from the Tasman Sea are projected to dominate, preventing significant diurnal thermal uplift. Climatological normals for early May sit around 15.5°C, reinforcing the barrier. 90% NO — invalid if a strong northerly gradient develops post-frontal passage.
