Climatological Aspects of Radiation Fog Occurrence at Albany, New York

Abstract

We present a detailed investigation of the local radiation fog climatology, carried out in support of our ongoing field program to study radiation fog mechanisms at Albany, New York. At Albany, a distinct "radiation fog season" is observed during September and October. We show that this late-summer{sol}early-autumn maximum in radiation fog observations is primarily due to a sufficient period of nocturnal cooling coupled with an adequate moisture supply. Five critical surface synoptic patterns are responsible for initiating the radiation fog process. In addition, radiation fog life cycles are generally confined to a modest time window centered on sunrise. Key parameters necessary for forecasting the onset time of fog are shown to be the initial relative humidity and nocturnal cooling rate.