Explaining the chill this morning: Radiational Cooling
Most of the region saw their coolest temperatures of the fall-season this morning. However, urban areas did not — the most extreme examples of the discrepancy were lows of 29 and 32 degrees at Westhampton Beach Airport, NY (KFOK) and Somerset Airport, NJ (KSMQ) respectively, while Central Park (KNYC) and LaGuardia Airport (KLGA) had lows of 50 and 52, respectively. There are often temperature differences between urban and suburban/rural areas, but not of this magnitude. The phenomenon is not without precedent, however, and once explained — it actually makes a ton of sense.
What do we know, to start, about radiational cooling? For one, we know that everything radiates heat. During the daytime hours, the suns incoming radiation serves as a heat source. But with nightfall, and the loss of daytime heating, the surface will continue to radiate the days heat outward — and cool. This is called, by definition, radiational cooling.
