Current National Weather Service and ensemble model guidance for New York City shows considerable spread in the overnight low for May 19–20, with GFS and ECMWF runs projecting a range from the low 50s°F under clear skies and light northwest winds to the upper 60s°F if thicker cloud cover or a warmer air mass lingers. This uncertainty stems from the position of an approaching trough and variable radiational cooling rates, which directly influence whether the minimum temperature settles in the 63°F-or-below bin or climbs toward 82°F or higher. Historical climatology places the typical mid-May Central Park low near 54–58°F, so traders are weighing how quickly any post-frontal clearing develops against the risk of delayed cooling. Updated model runs and National Weather Service briefings through the weekend will likely narrow the spread ahead of market resolution.