ECMWF 00z and GFS 12z ensemble means for April 29 consistently depict a robust northerly flow pattern over Île-de-France, promoting polar air advection. The 850 hPa isotherm analysis indicates anomalies -3 to -5°C below climatological averages. Upper-level troughing is forecast to maintain cold airmass dominance. This synoptic setup strongly signals a suppressed thermal profile. Consequently, peak diurnal warming will struggle to breach 16°C. 95% YES — invalid if the Azores High ridge extends eastward.
ECMWF 00z and GFS 12z ensemble means for April 29 consistently depict a robust northerly flow pattern over Île-de-France, promoting polar air advection. The 850 hPa isotherm analysis indicates anomalies -3 to -5°C below climatological averages. Upper-level troughing is forecast to maintain cold airmass dominance. This synoptic setup strongly signals a suppressed thermal profile. Consequently, peak diurnal warming will struggle to breach 16°C. 95% YES — invalid if the Azores High ridge extends eastward.
