Dense fog tonight will once again be an issue to contend with tonight into early on Monday. Some portions of our region have not seen the dense fog lift all day long and with the loss of daylight shortly, the fog should only expand. The widespread near zero visibilities of the past 24 hours may not occur overnight as there will be a bit of a south wind, although it will be very light. But still widespread one-quarter of mile visibilities with some pockets of visibilities around zero can be expected. The inversion looks to stay intact most of the night. A cold front moves in early on Monday and the wind and flow increasing prior to the passage may result in enough mixing to scour out the fog. We shall see. Today’s fog prevented us from warming to the expected highs.
Temperatures should hold steady or rise a few degrees prior to the morning cold front passage. Temperatures could creep up through the fifties throughout Monday Morning, before slowly falling through the afternoon and evening as it becomes breezy with gusts of 25 to 30 MPH. By late Monday Night, temperatures are expected to drop steadily as a wave of low pressure develops and moves northward along a slowly, southeastward moving cold front. The temperature profile will slowly become more favorable for sleet and wet snow to mix with rain, especially north and west of Philadelphia. More details can be found in our previous post.
A second piece of energy may impact our region for Tuesday Afternoon/Evening into Wednesday. Temperatures by this point may even be slightly colder. The question is how far north will be the measurable precipitation be falling. Still, the temperature profile appears to support some sort of mixed precipitation event with sleet, wet snow, and rain across the region should measurable precipitation fall. By Wednesday Morning, the remaining falling precipitation may be mostly of the frozen variety.
During Monday, Tuesday, and Wednesday…skies should be mostly cloudy between intervals of precipitation.