Wednesday Afternoon Update
Posted by Trevor Cole in Daily Weather Updates on 30-12-2009
Clouds are increasing across the tri-state ahead of a two stage storm system. Temps have begun to level off (were increasing at a steady pace earlier) due to evaporational cooling (cooling due to evaporating water droplets/ice crystals) and the increased cloud cover. However, even with marginal surface temps, the mid and upper levels of the atmosphere are still cold enough to support snow (850s below 0 and the 540 critical thickness line is south of the river). Given the slowed warming and colder column, most areas will start as all snow this afternoon/evening, with rain mixing in later tonight for areas inside and SSW of the 275 loop. Areas NNE of the loop look to stay mostly snow through the entire event, adding up to an inch or two in spots. Given the marginal surface temps, however, most paved surfaces will stay wet.
