Pennsylvania, 2009

Astronomical Low Tide in Pennsylvania, December 29, 2009

December 29, 2009 · NWS PHI · 2 events in 2 counties and zones

The combination of the strong northwest winds during the day on the 29th and the larger tide ranges associated with the approaching full moon spring tides produced blowout tides during the early evening low tide on the 29th. 54 feet below mean lower low water.

Where it happened

Every event with a place to put it; 2 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
2

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.

The combination of the strong northwest winds during the day on the 29th and the larger tide ranges associated with the approaching full moon spring tides produced blowout tides during the early evening low tide on the 29th. In Philadelphia, the low tide reached 2.54 feet below mean lower low water. Low water problems start at 1.80 feet below mean lower low water.

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 29, 4:44 PM EST, 16 minutes earlier.

Area forecast discussion, Dec 29, 4:44 PM EST, 16 minutes before
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Hazardous weather outlook, Dec 29, 4:40 PM EST, 20 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

2 astronomical low tide. Local standard time, as filed.

Astronomical Low Tide, Delaware

When
December 29, 5:00 PM EST to 7:00 PM EST
Where
Delaware forecast zone
Reported by
C-MAN Station
Coordinates
39.917, -75.399 (the zone’s center; the record gives no point)

Astronomical Low Tide, Philadelphia

When
December 29, 6:00 PM EST to 8:00 PM EST
Where
Philadelphia forecast zone
Reported by
C-MAN Station
Coordinates
40.008, -75.134 (the zone’s center; the record gives no point)

What these are

Astronomical Low Tide
Unusually low water from tides and offshore wind that caused impacts.

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

The same day elsewhere

More

Every storm in Pennsylvania in 2009Every state in 2009This day in weather historyWarnings in Pennsylvania, December 2009

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 2026-09-30. Each event’s entry at NCEI: 206366, 206365.