It was a calm and sunny end to the weekend with well above temperatures in the mid 40s. We have mainly clear skies this evening and temperatures are falling fast. Already 30 degrees in Harrisburg. Lows will drop into the mid and upper 20s. There will be some clouds streaming in as a weak frontal boundary drops south.
Monday will bring a chance for some wintry precip. Low pressure will spread a light snowfall north of the turnpike with more of a mix south of the turnpike Monday afternoon. There will be a period of snow but as the low moves in so does some milder air which will mix or change the snow to rain, especially along the MD border from Adams to Lancaster County. Temperatures will get to the mid and upper 30s by the afternoon.
Christmas is looking quiet. Sunshine by the afternoon which highs in the low 40s.
The next more significant storm will form over the Lower Mississippi Valley during the day Christmas and move in our direction by Wednesday. There is still uncertainty with respect to the timing and intensity of a secondary low that will form then strengthen near the Mid-Atlantic coast Wednesday night. This will play an important role in what type and intensity of the precipitation to cross our area. The heaviest snow looks to remain just to our north but we could see a period of snow before warmer air in the mid levels comes streaming in causing the snow to mix or change to sleet and rain at times. I will keep you posted.
Temperatures turn colder towards the end of the week. It looks like another quick moving system Saturday could bring a shot a rain or snow showers.