The sun was shining brightly Sunday morning and temperatures climbed into the mid-40s by early afternoon. But that could certainly be called the calm before the storm.

The National Weather Service (NWS) issued a winter weather advisory Sunday for Northumberland and other central Pennsylvania counties as a weather system approaches that was expected to bring as much as 3 to 5 inches of snow starting a little after midnight.

The heaviest snow was expected to fall this morning and early afternoon and will likely taper off around noon with road conditions improving by late afternoon, NWS Meteorologist Kevin Fitzgerald said.

The storm - the 16th in the last three months to bring anywhere from a coating to 5 inches to the greater Shamokin area - approached from the mid-Mississippi Valley, moved into central Pennsylvania during the evening and was expected to deliver moderate to heavy snow that is expected to last through much of today. The advisory is in effect until 8 p.m. today for most of central Pennsylvania south of Interstate 80.

Winds are expected to come from the northeast at 5 to 10 mph, with gusts of up to 20 mph. Temperatures are expected be in the upper 20s to lower 30s.

This will be the second snowstorm in a week, testing the patience of those who are ready for spring. Last Monday, the region dealt with about 3 inches.

Parts of Pennsylvania from Altoona west are under a winter storm warning, with accumulations of 6 to 8 inches expected over the Laurel Highlands.

Fitzgerald said the rest of the week looks "quite dry" in Northumberland County with below normal temperatures, but there may be chances of flurries slightly west of the county.