Winter Weather in Pennsylvania, January 11 to 12, 2015

Name: Winter Weather in Pennsylvania, January 11 to 12, 2015
Start: 2015-01-11T22:00
End: 2015-01-12T12:00
Location: Pennsylvania

January 11 to 12, 2015 · NWS PHI · 13 events in 13 counties and zones

Where it happened

Every event with a place to put it; 13 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 13

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS PHI wrote it up.

A wintry mix of precipitation, primarily freezing rain, affected all of Eastern Pennsylvania from the late night of the 11th into the morning of the 12th. Snow and sleet accumulations were only a couple of tenths of an inch and mainly over the higher terrain, while ice accumulations reached as high as around one tenth of an inch in the northern Philadelphia suburbs, Berks County and the Lehigh Valley. Because most of the wintry precipitation fell at night on the heels of an unseasonably cold air mass, untreated roadways and walkways were hazardous. Most of the main thoroughfares were treated and the relative number of accidents was low. However, accidents were reported along Interstate 76 (Schuylkill Expressway and Pennsylvania Turnpike) in the Philadelphia area. Speed restrictions were in place on the Pennsylvania Turnpike as well as the interstates in the Poconos. Some schools in the Lehigh Valley were closed. Other schools in Eastern Pennsylvania had delayed openings.

Precipitation started as sleet around Midnight EST on the 12th, except as snow shortly after Midnight EST in the Poconos. In the Poconos, the snow changed to sleet by 4 a.m. EST on the 12th, freezing rain by around 6 a.m. EST on the 12th and rain by 9 a.m. EST on the 12th. In and around the immediate Philadelphia area, precipitation was mixed with rain from the onset and became just plain rain after 7 a.m. EST on the 12th. In the Philadelphia northern suburbs, Berks County and the Lehigh Valley the sleet changed to freezing around 3 a.m. EST on the 12th and then changed to plain rain during the morning of the 12th. The rain ended during the afternoon of the 12th.

Snow accumulations included 0.2 of an inch in Bowmanstown and Lehighton in Carbon County. Ice accumulations included 0.1 of an inch in Martins Creek (Northampton County), West Rockhill Township (Bucks County), Kutztown (Berks County) and Exton (Chester County), 0.07 inches in Reading (Berks County), 0.05 inches in Schnecksville (Lehigh County), Mount Pocono (Monroe County) and Spring Mount (Montgomery County) and 0.03 inches in Wayne (Delaware County).

The wintry mix of precipitation was caused by the combination of a low pressure system that moved northeast from the Tennessee Valley and an approaching cold front from the Great Lakes. A retreating arctic air mass left enough cold air in place for precipitation to fall as a wintry mix until it was eroded during the morning of the 12th. Precipitation ended as the cold front approached Eastern Pennsylvania that afternoon.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before the first event at Jan 11, 6:56 PM EST, 3 hours 4 minutes earlier.

Area forecast discussion, Jan 11, 6:56 PM EST, 3 hours 4 minutes before

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Hazardous weather outlook, Jan 11, 3:55 PM EST, 6 hours 5 minutes before

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The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

13 winter weather. Local standard time, as filed.

Winter Weather, Western Chester

When: January 11, 10:00 PM EST to January 12, 9:00 AM EST
Where: Western Chester forecast zone
Reported by: Trained Spotter
Coordinates: 39.973, -75.748 (the zone’s center; the record gives no point)

Winter Weather, Berks

When: January 11, 11:00 PM EST to January 12, 10:00 AM EST
Where: Berks forecast zone
Reported by: Trained Spotter
Coordinates: 40.416, -75.926 (the zone’s center; the record gives no point)

Winter Weather, Lehigh

When: January 11, 11:00 PM EST to January 12, 10:00 AM EST
Where: Lehigh forecast zone
Reported by: Trained Spotter
Coordinates: 40.613, -75.592 (the zone’s center; the record gives no point)

Winter Weather, Northampton

When: January 11, 11:00 PM EST to January 12, 11:00 AM EST
Where: Northampton forecast zone
Reported by: Trained Spotter
Coordinates: 40.754, -75.307 (the zone’s center; the record gives no point)

Winter Weather, Eastern Chester

When: January 11, 11:00 PM EST to January 12, 9:00 AM EST
Where: Eastern Chester forecast zone
Reported by: Trained Spotter
Coordinates: 39.973, -75.748 (the zone’s center; the record gives no point)

Winter Weather, Western Montgomery

When: January 11, 11:00 PM EST to January 12, 11:00 AM EST
Where: Western Montgomery forecast zone
Reported by: Trained Spotter
Coordinates: 40.211, -75.367 (the zone’s center; the record gives no point)

Winter Weather, Eastern Montgomery

When: January 11, 11:00 PM EST to January 12, 10:00 AM EST
Where: Eastern Montgomery forecast zone
Reported by: Trained Spotter
Coordinates: 40.211, -75.367 (the zone’s center; the record gives no point)

Winter Weather, Delaware

When: January 12, 12:00 AM EST to 8:00 AM EST
Where: Delaware forecast zone
Reported by: Trained Spotter
Coordinates: 39.917, -75.399 (the zone’s center; the record gives no point)

Winter Weather, Philadelphia

When: January 12, 12:00 AM EST to 7:30 AM EST
Where: Philadelphia forecast zone
Reported by: ASOS
Coordinates: 40.008, -75.134 (the zone’s center; the record gives no point)

Winter Weather, Upper Bucks

When: January 12, 12:00 AM EST to 12:00 PM EST
Where: Upper Bucks forecast zone
Reported by: Social Media
Coordinates: 40.337, -75.107 (the zone’s center; the record gives no point)

Winter Weather, Lower Bucks

When: January 12, 12:00 AM EST to 11:00 AM EST
Where: Lower Bucks forecast zone
Reported by: Social Media
Coordinates: 40.337, -75.107 (the zone’s center; the record gives no point)

Winter Weather, Carbon

When: January 12, 1:00 AM EST to 9:00 AM EST
Where: Carbon forecast zone
Reported by: CoCoRaHS
Coordinates: 40.918, -75.709 (the zone’s center; the record gives no point)

Winter Weather, Monroe

When: January 12, 1:30 AM EST to 9:00 AM EST
Where: Monroe forecast zone
Reported by: ASOS
Coordinates: 41.058, -75.339 (the zone’s center; the record gives no point)

What these are

Winter Weather: Snow, sleet or freezing rain below warning levels that still caused disruption, damage or casualties.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Pennsylvania in 2015 Every state in 2015 This day in weather history Warnings in Pennsylvania, January 2015

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 553620, 553616, 553617, 553619, 553621, 553622, 553624, 553625, 553626, 553627, 553628, 553629, 553630.