An area of high pressure early on the 10th gave way to an advancing low pressure system which traveled up the Ohio Valley. This system moved across the region during the nighttime hours of the 10th and then tracked to the northeast during the morning of the 11th. Moisture in the form of snow and rain overspread the area from southwest to northeast during the day on the 10th. Some of the snow was moderate to occasionally heavy for a time across northeastern Pennsylvania. As milder air worked its way into the area, the snow and rain mixed with sleet and then changed over to some freezing rain and plain rain. The precipitation ended from west to east during the morning hours of the 11th.
While most roadways in Berks County remained relatively clear on the 10th, the weather conditions helped cause some accidents, including one that closed eastbound Interstate 78 in Greenwich Township for more than an hour in the afternoon. The driver of the truck involved was taken to a local hospital and was in satisfactory condition. Road conditions worsened during the night of the 10th as more frozen precipitation occurred. Numerous ambulance calls in Lehigh County were received during the snowstorm on the 10th, which were for people who were injured from falls. This was due to ice that was still in place, but then new snow fell on top of it, which resulted in walkways and other untreated surfaces being extra icy. Snow emergencies were called by numerous municipalities on the 11th, which implemented specific parking rules. Meanwhile, roadways in Northampton County turned rather slippery during the 10th due to snow, which resulted in numerous accidents. The majority of the accidents were minor, although some involved injuries. Minor accidents were reported on Interstate 78.
Some specific snowfall totals included; 6.0 inches in Delaware Water Gap (Monroe County), 5.5 inches in Bossardsville (Monroe County), 5.0 inches in Albrightsville (Carbon County), 4.4 inches in Walnutport (Northampton County), 4.3 inches in Tobyhanna (Monroe County), 4.0 inches in Jim Thorpe (Carbon County), 3.4 inches in Glendon (Northampton County), 3.3 inches in Middle (Monroe County), 3.0 inches in Lehighton (Carbon County), 2.8 inches in Catasauqua (Lehigh County), 2.7 inches in Martins Creek (Northampton County), 2.6 inches at the Lehigh Valley International Airport (Lehigh County), 2.5 inches in Bethlehem (Northampton County), 2.0 inches in Quakertown (Bucks County), 2.0 inches in East Allentown (Lehigh County), 1.9 inches in Perkasie (Bucks County), 1.1 inches in Furlong (Bucks County), 1.0 inch in Reading (Berks County), 0.8 of an inch in Trappe (Montgomery County), 0.6 of an inch in Villanova (Delaware County), 0.5 of an inch in East Nantmeal Township (Chester County), 0.5 of an inch in Lansdale (Montgomery County), 0.4 of an inch in Somerton (Philadelphia County) and 0.1 of an inch at the Philadelphia International Airport (Philadelphia County). Ice accumulations were generally less than one tenth of an inch.

Winter Weather in MONTGOMERY, PENNSYLVANIA
From 10-JAN-09 04:00:00 to 11-JAN-09 01:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snow overspread the region during the early morning hours of the 10th. There was then a break for a few hours from about mid-morning to midday, then another round of snow moved in, some of which was moderate. As some milder air moved in above the surface, the snow mixed with sleet then changed to some freezing rain before ending during the early morning hours of the 11th. The combination of temperatures below freezing, fallen snow and a little icing on top, produced slippery conditions.

Winter Weather in BUCKS, PENNSYLVANIA
From 10-JAN-09 06:00:00 to 11-JAN-09 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snow overspread the region during the early morning hours of the 10th. There was then a break for a few hours from about mid-morning to midday, then another round of snow moved in, some of which was moderate. As some milder air moved in above the surface, the snow mixed with sleet then changed to some freezing rain before ending during the early morning hours of the 11th. The combination of temperatures below freezing, fallen snow and a little icing on top, produced slippery conditions.

Winter Weather in DELAWARE, PENNSYLVANIA
From 10-JAN-09 12:00:00 to 11-JAN-09 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Light snow overspread the region during the midday hours of the 10th. The snow then changed to a mix of rain and sleet with even a few pockets of freezing rain. There was a break for a few hours from about late in the afternoon through early evening, then a round of light rain and snow moved in. The combination of temperatures right around freezing and some snow and ice produced slippery conditions, especially on bridges, overpasses and other elevated structures.

Winter Weather in PHILADELPHIA, PENNSYLVANIA
From 10-JAN-09 12:00:00 to 11-JAN-09 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Light snow overspread the region during the midday hours of the 10th. The snow then changed to a mix of rain and sleet with even a few pockets of freezing rain. There was a break for a few hours from about late in the afternoon through early evening, then a round of light rain and snow moved in. The combination of temperatures right around freezing and some snow and ice produced slippery conditions, especially on bridges, overpasses and other elevated structures.

Winter Weather in LEHIGH, PENNSYLVANIA
From 10-JAN-09 05:00:00 to 11-JAN-09 01:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snow overspread the region during the early morning hours of the 10th. There was then a break for a few hours from about mid-morning to midday, then another round of snow moved in, some of which was moderate to occasionally heavy. As some milder air moved in above the surface, the snow mixed with sleet then changed to some freezing rain before ending during the early morning hours of the 11th. The combination of temperatures below freezing, fallen snow and a little icing on top, produced slippery conditions.

Winter Weather in NORTHAMPTON, PENNSYLVANIA
From 10-JAN-09 05:00:00 to 11-JAN-09 01:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snow overspread the region during the early morning hours of the 10th. There was then a break for a few hours from about mid-morning to midday, then another round of snow moved in, some of which was moderate to occasionally heavy. As some milder air moved in above the surface, the snow mixed with sleet then changed to some freezing rain before ending during the early morning hours of the 11th. The combination of temperatures below freezing, fallen snow and a little icing on top, produced slippery conditions.

Winter Storm in CARBON, PENNSYLVANIA
From 10-JAN-09 07:00:00 to 11-JAN-09 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snow overspread the area during the morning of the 10th, then there was a brief break around midday. More snow arrived and it became moderate to occasionally heavy during the afternoon and evening. As milder air moved in above the surface, the snow mixed with a little sleet then changed to a period of freezing rain before ending during the early morning hours of the 11th. The combination of temperatures below freezing, bursts of snow and a little icing on top, produced hazardous conditions.

Winter Storm in MONROE, PENNSYLVANIA
From 10-JAN-09 07:00:00 to 11-JAN-09 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snow overspread the area during the morning of the 10th, then there was a brief break around midday. More snow arrived and it became moderate to occasionally heavy during the afternoon and evening. As milder air moved in above the surface, the snow mixed with a little sleet then changed to a period of freezing rain before ending during the early morning hours of the 11th. The combination of temperatures below freezing, bursts of snow and a little icing on top, produced hazardous conditions.

Winter Weather in BERKS, PENNSYLVANIA
From 10-JAN-09 04:00:00 to 11-JAN-09 01:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snow overspread the region during the early morning hours of the 10th. There was then a break for a few hours from about mid-morning to midday, then another round of snow moved in, some of which was moderate to occasionally heavy. As some milder air moved in above the surface, the snow mixed with sleet then changed to some freezing rain before ending during the early morning hours of the 11th. The combination of temperatures below freezing, fallen snow and a little icing on top, produced slippery conditions.

Winter Weather in CHESTER, PENNSYLVANIA
From 10-JAN-09 04:00:00 to 11-JAN-09 01:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snow overspread the region during the early morning hours of the 10th. There was then a break for a few hours from about mid-morning to midday, then another round of snow moved in, some of which was moderate. As some milder air moved in above the surface, the snow mixed with sleet then changed to some freezing rain before ending during the early morning hours of the 11th. The combination of temperatures below freezing, fallen snow and a little icing on top, produced slippery conditions.