National Weather Service ensemble guidance and recent GFS-ECMWF model runs project a daytime high near 77°F for New York City on May 16 under a building high-pressure ridge promoting clear skies and light southerly flow. Subsidence within the ridge suppresses cloud development and maximizes solar insolation, while the mild advection supports modest boundary-layer warming without significant instability or moisture return that could trigger convection and cap temperatures. Historical analogs for mid-May under similar synoptic patterns show highs clustering tightly around 75–78°F, aligning with the market-implied 80.5% probability for the 76–77°F bin. Traders are monitoring the afternoon observational update from LaGuardia Airport, with only minor model spread leaving limited room for an 80°F+ outlier.