Synoptic analysis indicates persistent zonal flow, preventing robust northerly advection. ECMWF 10-day ensemble means show a high probability of a low-amplitude trough passage around April 26-27, leading to increased cloud cover and a sustained insolation deficit. Coupled with the typical diurnal range for late autumn, thermal lift will be limited. Current surface isobaric gradients don't support significant Foehn effect. This dampens any potential for temperatures to breach the 16°C isotherm. The climatological mean is marginal, but current prognostic charts lean conservative. 85% NO — invalid if a strong Tasman Sea high ridge develops providing sustained NW flow.
