PAINTED SHORES
MENUBegin
PA · NOAA 8545240 · 39° 56′ N · 75° 09′ W
Tides at Philadelphia
A semidiurnal tide (form factor 0.20), spring this week. Predicted from the station's 35 harmonic constants; heights above mean lower low water, times in station time. Weather is not in these numbers.
This week
| When | Water | Height |
|---|---|---|
| Sun, Oct 25, 8:28 PM | Low | 0.5 ft |
| Mon, Oct 26, 1:52 AM | High | 6.3 ft |
| Mon, Oct 26, 8:38 AM | Low | 0.6 ft |
| Mon, Oct 26, 2:09 PM | High | 7.1 ft |
| Mon, Oct 26, 9:20 PM | Low | 0.5 ft |
| Tue, Oct 27, 2:38 AM | High | 6.2 ft |
| Tue, Oct 27, 9:24 AM | Low | 0.6 ft |
| Tue, Oct 27, 2:51 PM | High | 7.2 ft |
| Tue, Oct 27, 10:11 PM | Low | 0.6 ft |
| Wed, Oct 28, 3:25 AM | High | 6.0 ft |
| Wed, Oct 28, 10:11 AM | Low | 0.6 ft |
| Wed, Oct 28, 3:38 PM | High | 7.2 ft |
| Wed, Oct 28, 11:03 PM | Low | 0.6 ft |
| Thu, Oct 29, 4:16 AM | High | 5.9 ft |
| Thu, Oct 29, 11:02 AM | Low | 0.7 ft |
| Thu, Oct 29, 4:29 PM | High | 7.0 ft |
| Thu, Oct 29, 11:57 PM | Low | 0.7 ft |
| Fri, Oct 30, 5:11 AM | High | 5.7 ft |
| Fri, Oct 30, 11:56 AM | Low | 0.7 ft |
| Fri, Oct 30, 5:26 PM | High | 6.8 ft |
| Sat, Oct 31, 12:52 AM | Low | 0.8 ft |
| Sat, Oct 31, 6:11 AM | High | 5.6 ft |
| Sat, Oct 31, 12:53 PM | Low | 0.8 ft |
| Sat, Oct 31, 6:29 PM | High | 6.6 ft |
| Sun, Nov 1, 1:49 AM | Low | 0.8 ft |
| Sun, Nov 1, 6:14 AM | High | 5.5 ft |
| Sun, Nov 1, 12:53 PM | Low | 0.8 ft |
The constants that make it
| Constituent | Amplitude | Phase |
|---|---|---|
| M2 | 2.7 ft | 184.2° |
| N2 | 0.5 ft | 166.5° |
| SA | 0.4 ft | 126.7° |
| K1 | 0.3 ft | 281.1° |
| L2 | 0.3 ft | 198.9° |
| S2 | 0.3 ft | 224.3° |
| M4 | 0.3 ft | 252.5° |
| O1 | 0.3 ft | 264.9° |
The eight largest of 35. Source: NOAA CO-OPS harmonic constituents for 8545240, public domain.
The year as a print
The last two days, measured
At Sun, Oct 25 16:24 the gauge read 4.8 ft, 0.5 ft above the computed curve: wind and pressure, not the moon. The widest gap of the two days was 1.7 ft, at Fri, Oct 23 20:18.
- Computed here, from the constants
- NOAA's own prediction
- Measured at the gauge, every six minutes
The last twelve hours as numbers
| Station time | Measured | Computed here | NOAA |
|---|---|---|---|
| Sun, Oct 25 05:00 | 3.66 ft | 2.74 ft | 2.74 ft |
| Sun, Oct 25 06:00 | 2.57 ft | 1.75 ft | 1.74 ft |
| Sun, Oct 25 07:00 | 1.58 ft | 0.92 ft | 0.92 ft |
| Sun, Oct 25 08:00 | 0.92 ft | 0.57 ft | 0.57 ft |
| Sun, Oct 25 09:00 | 2.40 ft | 1.40 ft | 1.39 ft |
| Sun, Oct 25 10:00 | 4.29 ft | 3.26 ft | 3.26 ft |
| Sun, Oct 25 11:00 | 5.70 ft | 5.04 ft | 5.04 ft |
| Sun, Oct 25 12:00 | 6.67 ft | 6.20 ft | 6.20 ft |
| Sun, Oct 25 13:00 | 7.41 ft | 6.87 ft | 6.87 ft |
| Sun, Oct 25 14:00 | 7.41 ft | 6.83 ft | 6.83 ft |
| Sun, Oct 25 15:00 | 6.45 ft | 5.98 ft | 5.99 ft |
| Sun, Oct 25 16:00 | 5.23 ft | 4.79 ft | 4.80 ft |
Measured heights from NOAA CO-OPS station 8545240, preliminary, above mean lower low water. The print carries the computed curve only: one year, no weather.