After a soggy Sunday which provided much-needed rain to Pennsylvania, high pressure will build across the Commonwealth, with the sun finally returning today. The high pressure will allow for a northwesterly flow to maintain its grip over the region for the first part of the week, keeping the state’s temperatures well below-average for this time of year. There is the potential for frost formation through Thursday north and west, particularly overnight tonight. Tuesday will be on the breezy side. Some moisture off of Lake Erie is possible, and with very cold air aloft, some wet snow flakes mixing in isn’t out of the question north of I-80. On the bright side, the sun will dominate the region overall, with afternoon highs creeping up a bit each day and returning to around average by the end of the week.