By Kathy Orr

PHILADELPHIA (CBS) — Low pressure developing off the Mid-Atlantic is tracking northeast and spreading rain into our area.

New information Tuesday night suggests the threat of rain mixing with and changing to a wet snow Wednesday. The heaviest precipitation will be late Wednesday into the evening. One to three inches of wet snow are possible along the I-95 corridor, and adjacent suburbs, accumulating mainly on the grassy surfaces.

Upper level temperatures still support snow from southern NJ on north and west, but surface temps are marginal. With a cold dry air mass in place Tuesday night, the onset of the precipitation Wednesday will allow the temperatures to drop as the moisture evaporates initially. Rain will develop during the morning Wednesday and change over to some wet snow. The snow will have a tough time sticking to the roads during the day, however, if it falls heavy enough, especially after sunset, it could stick on some roads. The higher elevations have the best chance of seeing some light accumulation. Any leftover showers or snow showers will end Thursday morning as the storm lifts northeast.

A winter storm warning advisory has been issued Wednesday through early Thursday AM for inland southern NJ up through the southern Poconos, for a couple of inches possible north & west of Philadelphia, and lesser amounts south and east. This will depend on the track of the storm. If the track shifts farther east, the higher amounts will shift farther to the coast.

Coastal Flood Warnings and High Wind Warnings are in effect Wednesday morning through Thursday morning for the NJ and DE coast. A wind advisory has been issued for Phila. and surrounding suburbs from Wednesday through early Thursday morning. The Shore will see the main impacts with wind gusts 50-65 mph, 1-2″ of rain, and moderate tidal flooding. The times of the high tides of concern are early afternoon on Wednesday and 2 to 3am Thursday morning. The earlier the wind switches offshore (northwest) the better, as the flow of wind will push the water back out to seas and end the flooding threat.