ECMWF ops and GFS ensemble mean show high-confidence convergence around 56-57°F for NYC nocturnal lows on May 5. A post-frontal, transient ridging pattern sets up favorable boundary layer stability. Critically, forecast 850mb temps of +8C coupled with weak southerly advection and scattered mid-level cloud deck will temper radiative cooling. Urban heat island effect will elevate surface temps, precisely landing within the target range. 90% YES — invalid if frontal passage accelerates by >6 hours.
ECMWF ops and GFS ensemble mean show high-confidence convergence around 56-57°F for NYC nocturnal lows on May 5. A post-frontal, transient ridging pattern sets up favorable boundary layer stability. Critically, forecast 850mb temps of +8C coupled with weak southerly advection and scattered mid-level cloud deck will temper radiative cooling. Urban heat island effect will elevate surface temps, precisely landing within the target range. 90% YES — invalid if frontal passage accelerates by >6 hours.
