Pennsylvania, 1999

Heavy Rain in Pennsylvania, December 13 to 14, 1999

December 13 to 14, 1999 · NWS PHI · 5 events in 5 counties and zones

A slow moving low pressure system moved northeast from southern Texas the morning of the 12th into southern Mississippi the morning of the 13th and into West Virginia the morning of the 14th. A second low pressure system formed near the Delmarva Peninsula during the day on the 14th and moved well offshore that night.

Where it happened

Every event with a place to put it; 5 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

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
5

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 slow moving low pressure system moved northeast from southern Texas the morning of the 12th into southern Mississippi the morning of the 13th and into West Virginia the morning of the 14th. A second low pressure system formed near the Delmarva Peninsula during the day on the 14th and moved well offshore that night. The slow movement by the low gave the region about 24 hours of steady rain from noon on the 13th into the mid afternoon of the 14th. The heaviest rain (about two-thirds of the storm total) fell during the morning and early afternoon of the 14th. Storm totals averaged around an inch and a half. There was some urban and poor drainage flooding, but no other problems were reported. Storm totals included 1.78 inches at the Franklin Institute within Philadelphia, 1.77 inches in Fricks (Bucks County), 1.63 inches in West Chester (Chester County), 1.56 inches in Neshaminy Falls (Bucks County), 1.53 inches at the Northeast Philadelphia Airport, 1.35 inches in Pottstown (Montgomery County), 1.29 inches in Valley Forge (Chester County), 1.28 inches in Palm (Montgomery County) 1.24 inches at the Philadelphia International Airport and 1.22 inches in Springtown (Bucks County).

The radar

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

Open the radar archive at this moment

Event by event

5 heavy rain. Local standard time, as filed.

Heavy Rain, Bucks

When
December 13, 12:00 PM EST to December 14, 4:00 PM EST
Where
Bucks County, Countywide
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
40.337, -75.107 (the zone’s center; the record gives no point)

Heavy Rain, Chester

When
December 13, 12:00 PM EST to December 14, 4:00 PM EST
Where
Chester County, Countywide
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
39.973, -75.748 (the zone’s center; the record gives no point)

Heavy Rain, Delaware

When
December 13, 12:00 PM EST to December 14, 4:00 PM EST
Where
Delaware County, Countywide
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
39.917, -75.399 (the zone’s center; the record gives no point)

Heavy Rain, Montgomery

When
December 13, 12:00 PM EST to December 14, 4:00 PM EST
Where
Montgomery County, Countywide
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
40.211, -75.367 (the zone’s center; the record gives no point)

Heavy Rain, Philadelphia

When
December 13, 12:00 PM EST to December 14, 4:00 PM EST
Where
Philadelphia County, Countywide
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
40.008, -75.134 (the zone’s center; the record gives no point)

What these are

Heavy Rain
Rainfall totals unusual for the place and season that did not produce a flood.

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

The same day elsewhere

More

Every storm in Pennsylvania in 1999Every state in 1999This day in weather historyWarnings in Pennsylvania, December 1999

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: 5720520, 5720521, 5720522, 5720523, 5720524.