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PR · NOAA 9755371 · 18° 28′ N · 66° 07′ W
Tides at San Juan, La Puntilla, San Juan Bay
A mixed, mainly semidiurnal tide (form factor 0.94), spring this week. Predicted from the station's 34 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, 7:50 PM | High | 1.2 ft |
| Mon, Oct 26, 1:58 AM | Low | 0.1 ft |
| Mon, Oct 26, 9:04 AM | High | 2.0 ft |
| Mon, Oct 26, 3:40 PM | Low | 0.6 ft |
| Mon, Oct 26, 8:30 PM | High | 1.2 ft |
| Tue, Oct 27, 2:38 AM | Low | -0.0 ft |
| Tue, Oct 27, 9:54 AM | High | 2.1 ft |
| Tue, Oct 27, 4:39 PM | Low | 0.6 ft |
| Tue, Oct 27, 9:13 PM | High | 1.1 ft |
| Wed, Oct 28, 3:22 AM | Low | -0.1 ft |
| Wed, Oct 28, 10:46 AM | High | 2.1 ft |
| Wed, Oct 28, 5:39 PM | Low | 0.6 ft |
| Wed, Oct 28, 9:58 PM | High | 1.1 ft |
| Thu, Oct 29, 4:12 AM | Low | -0.1 ft |
| Thu, Oct 29, 11:41 AM | High | 2.1 ft |
| Thu, Oct 29, 6:39 PM | Low | 0.7 ft |
| Thu, Oct 29, 10:49 PM | High | 1.0 ft |
| Fri, Oct 30, 5:08 AM | Low | -0.1 ft |
| Fri, Oct 30, 12:40 PM | High | 2.1 ft |
| Fri, Oct 30, 7:37 PM | Low | 0.7 ft |
| Fri, Oct 30, 11:47 PM | High | 1.0 ft |
| Sat, Oct 31, 6:09 AM | Low | 0.0 ft |
| Sat, Oct 31, 1:42 PM | High | 2.0 ft |
| Sat, Oct 31, 8:31 PM | Low | 0.7 ft |
| Sun, Nov 1, 12:58 AM | High | 1.1 ft |
| Sun, Nov 1, 7:14 AM | Low | 0.1 ft |
| Sun, Nov 1, 2:43 PM | High | 1.9 ft |
The constants that make it
| Constituent | Amplitude | Phase |
|---|---|---|
| M2 | 0.5 ft | 20.3° |
| K1 | 0.3 ft | 227.7° |
| O1 | 0.2 ft | 226.4° |
| SA | 0.2 ft | 181.4° |
| N2 | 0.1 ft | 358.3° |
| P1 | 0.1 ft | 228.9° |
| S2 | 0.1 ft | 49.4° |
| SSA | 0.0 ft | 38.3° |
The eight largest of 34. Source: NOAA CO-OPS harmonic constituents for 9755371, public domain.
The year as a print
The last two days, measured
At Sun, Oct 25 16:18 the gauge read 1.1 ft, 0.4 ft above the computed curve: wind and pressure, not the moon. The widest gap of the two days was 0.8 ft, at Sat, Oct 24 11:54.
- 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 | 1.72 ft | 1.11 ft | 1.10 ft |
| Sun, Oct 25 06:00 | 2.09 ft | 1.47 ft | 1.46 ft |
| Sun, Oct 25 07:00 | 2.37 ft | 1.73 ft | 1.72 ft |
| Sun, Oct 25 08:00 | 2.52 ft | 1.85 ft | 1.84 ft |
| Sun, Oct 25 09:00 | 2.51 ft | 1.81 ft | 1.81 ft |
| Sun, Oct 25 10:00 | 2.31 ft | 1.63 ft | 1.63 ft |
| Sun, Oct 25 11:00 | 1.92 ft | 1.35 ft | 1.36 ft |
| Sun, Oct 25 12:00 | 1.55 ft | 1.05 ft | 1.06 ft |
| Sun, Oct 25 13:00 | 1.21 ft | 0.77 ft | 0.78 ft |
| Sun, Oct 25 14:00 | 0.99 ft | 0.59 ft | 0.60 ft |
| Sun, Oct 25 15:00 | 0.98 ft | 0.56 ft | 0.57 ft |
| Sun, Oct 25 16:00 | 1.06 ft | 0.65 ft | 0.67 ft |
Measured heights from NOAA CO-OPS station 9755371, preliminary, above mean lower low water. The print carries the computed curve only: one year, no weather.