Snow and ice maps for the weekend:
- The 1st and 2nd images are the latest maps from the National Weather Service for snow and ice (freezing rain) through 7 PM Sunday.
- The 3rd image is for 1 AM Sunday from the NAM. It's showing sleet (orange) on Long Island, which will be followed by freezing rain.
- The 4th image shows the surface temperatures at 1 AM Sunday.
- The 5th image shows the temperatures (in degrees C) at 1 AM Sunday at the 850 mb level, which is a little less than a mile high, and you can see they are above freezing on Long Island. It's this warm layer aloft that is preventing it from falling as snow. The temperatures around 1/2 mile up are below freezing, so the rain freezes and becomes sleet. When the warmer layer gets closer to the ground, it will fall as plain rain, but freeze on contact with the colder ground surface, which is freezing rain. It was only about 0.1" of freezing rain that contributed to the deadly pile-up in Fort Worth, TX this morning.