Going into today, Pittsburgh had seen measurable snowfall on seven of the past nine days.

According to weather forecasters, today will make it eight of 10.

The National Weather Service was forecasting accumulations of 4 to 6 inches of snow by Saturday morning.

The city issued an alert Thursday afternoon saying the snow is expected to start between 9 a.m. and noon and be heaviest during today's evening rush. Road conditions will begin to deteriorate between noon and 2 p.m., the Public Works Department said.

A full complement of crews will be available to work 12-hour shifts, and the department has placed all of its vehicles and equipment into salting and plowing mode, the department said.

Pennsylvania Department of Transportation crews were expected to be out overnight pretreating with salt brine to slow the accumulation of snow on roads once the storm begins. Some roads were already covered with a salt residue and won't need to be retreated, spokesman Jim Struzzi said.

A relatively mild first half of January saw only one measurable snowfall, 0.8 inches on New Year's Day, and a high of 67 degrees on Jan. 13.

Since then, it has been mostly a downhill slide into more winterlike conditions, marked by the lowest temperature of the season, 4 degrees, recorded at Pittsburgh International Airport on Wednesday.

Through Wednesday, 5.3 inches of snow had fallen for the month, bringing the seasonal total to 19.8 inches, or about half of what falls in a typical winter here.

According to the weather service, snow showers will persist into Saturday with gusty winds and a high in the mid-20s. Sunshine and a high near 30 are forecast for Sunday, followed by a warmup early next week.

First Published: January 25, 2013, 10:00 a.m.