Latest model runs from the GFS, ECMWF, and NAM place NYC’s May 17 afternoon maximum in the mid-to-upper 80s, with the market’s near-even split between 86–87 °F and 88–89 °F reflecting subtle differences in predicted boundary-layer mixing depth and the timing of peak solar heating. A warm, dry air mass advecting from the southwest under mostly sunny skies and light southwesterly flow supports rapid daytime warming, while modest dew-point spreads limit cloud development. Historical May climatology for LaGuardia and Central Park shows highs near 75 °F, so the current setup represents a notable warm anomaly driven by the absence of onshore flow or significant cloud cover. National Weather Service forecast updates tomorrow morning will resolve the remaining spread before official observations are recorded.