Pennsylvania, 2008

Dense Fog in Pennsylvania, December 27 to 28, 2008

December 27 to 28, 2008 · NWS PHI · 6 events in 6 counties and zones

A warm and moist southerly flow over the relatively colder ground that preceded the passage of a warm front produced dense fog across most of Eastern Pennsylvania from the late morning on the 27th into the morning of the 28th. Philadelphia and the Poconos were least affected by the dense fog.

Where it happened

Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
6

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 warm and moist southerly flow over the relatively colder ground that preceded the passage of a warm front produced dense fog across most of Eastern Pennsylvania from the late morning on the 27th into the morning of the 28th. Philadelphia and the Poconos were least affected by the dense fog. The dense fog formed in the Lehigh Valley and Bucks County first and then spread outward as the 27th progressed. Many visibilities were one-quarter of a mile or less. The dense fog dissipated after the warm front moved through the eastern part of the state on the morning of the 28th.

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 Dec 27, 8:40 AM EST, 1 hour 20 minutes earlier.

Area forecast discussion, Dec 27, 8:40 AM EST, 1 hour 20 minutes before
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Hazardous weather outlook, Dec 27, 8:30 AM EST, 1 hour 30 minutes before
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In the hours before

Special weather statement, Dec 27, 9:18 AM EST, 42 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

6 dense fog. Local standard time, as filed.

Dense Fog, Lehigh

When
December 27, 10:00 AM EST to December 28, 5:00 AM EST
Where
Lehigh forecast zone
Reported by
ASOS
Coordinates
40.613, -75.592 (the zone’s center; the record gives no point)

Dense Fog, Northampton

When
December 27, 10:00 AM EST to December 28, 5:00 AM EST
Where
Northampton forecast zone
Reported by
ASOS
Coordinates
40.754, -75.307 (the zone’s center; the record gives no point)

Dense Fog, Bucks

When
December 27, 10:00 AM EST to December 28, 3:00 AM EST
Where
Bucks forecast zone
Reported by
ASOS

Dense Fog, Montgomery

When
December 27, 5:00 PM EST to December 28, 3:00 AM EST
Where
Montgomery forecast zone
Reported by
ASOS

Dense Fog, Chester

When
December 27, 6:00 PM EST to December 28, 3:00 AM EST
Where
Chester forecast zone
Reported by
ASOS

Dense Fog, Berks

When
December 27, 6:00 PM EST to December 28, 4:00 AM EST
Where
Berks forecast zone
Reported by
ASOS
Coordinates
40.416, -75.926 (the zone’s center; the record gives no point)

What these are

Dense Fog
Fog reducing visibility to a quarter mile or less, filed where it caused accidents or disruption.

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

The same day elsewhere

More

Every storm in Pennsylvania in 2008Every state in 2008This day in weather historyWarnings in Pennsylvania, December 2008

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: 143365, 143366, 143367, 143368, 143369, 143370.