The season's first measurable snowfall blanketed the higher elevations of the St. John Valley in northern Maine on Monday. By early afternoon close to four inches were on the ground and covering vehicles. The National Weather Service in Caribou was calling for snow showers to the north and rain toward the south today with some possible thunder. Drivers were urged to use caution on area roadways that could become slushy or during times of low visibility thanks to strong bands of snow moving through northern Maine this afternoon. All snow and rain was expected to clear out by early evening and conditions will be dry and cold through Thursday with some rain coming in for the weekend.