PAINTED SHORES
MENUBegin
LA · NOAA 8761724 · 29° 16′ N · 89° 57′ W
Tides at Grand Isle
A diurnal tide (form factor 9.31), spring this week. Predicted from the station's 29 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, 9:25 PM | High | 1.5 ft |
| Mon, Oct 26, 7:55 AM | Low | 0.2 ft |
| Mon, Oct 26, 9:41 PM | High | 1.6 ft |
| Tue, Oct 27, 9:06 AM | Low | 0.0 ft |
| Tue, Oct 27, 10:21 PM | High | 1.8 ft |
| Wed, Oct 28, 10:15 AM | Low | -0.1 ft |
| Wed, Oct 28, 11:16 PM | High | 1.8 ft |
| Thu, Oct 29, 11:20 AM | Low | -0.2 ft |
| Fri, Oct 30, 12:22 AM | High | 1.8 ft |
| Fri, Oct 30, 12:24 PM | Low | -0.2 ft |
| Sat, Oct 31, 1:30 AM | High | 1.8 ft |
| Sat, Oct 31, 1:27 PM | Low | -0.1 ft |
| Sun, Nov 1, 1:32 AM | High | 1.7 ft |
| Sun, Nov 1, 1:30 PM | Low | 0.1 ft |
The constants that make it
| Constituent | Amplitude | Phase |
|---|---|---|
| K1 | 0.4 ft | 34.8° |
| O1 | 0.4 ft | 27.9° |
| SA | 0.3 ft | 150.7° |
| SSA | 0.2 ft | 57.1° |
| P1 | 0.1 ft | 34.4° |
| Q1 | 0.1 ft | 11.4° |
| M2 | 0.1 ft | 160.9° |
| S2 | 0.0 ft | 147.8° |
The eight largest of 29. Source: NOAA CO-OPS harmonic constituents for 8761724, public domain.
The year as a print
The last two days, measured
At Sun, Oct 25 15:24 the gauge read 1.6 ft, 0.5 ft above the computed curve: wind and pressure, not the moon. The widest gap of the two days was 0.6 ft, at Sun, Oct 25 11:06.
- 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 04:00 | 1.00 ft | 0.52 ft | 0.54 ft |
| Sun, Oct 25 05:00 | 0.93 ft | 0.43 ft | 0.44 ft |
| Sun, Oct 25 06:00 | 0.87 ft | 0.38 ft | 0.39 ft |
| Sun, Oct 25 07:00 | 0.88 ft | 0.37 ft | 0.37 ft |
| Sun, Oct 25 08:00 | 0.92 ft | 0.39 ft | 0.39 ft |
| Sun, Oct 25 09:00 | 1.00 ft | 0.45 ft | 0.44 ft |
| Sun, Oct 25 10:00 | 1.11 ft | 0.54 ft | 0.53 ft |
| Sun, Oct 25 11:00 | 1.24 ft | 0.66 ft | 0.65 ft |
| Sun, Oct 25 12:00 | 1.31 ft | 0.78 ft | 0.76 ft |
| Sun, Oct 25 13:00 | 1.41 ft | 0.88 ft | 0.86 ft |
| Sun, Oct 25 14:00 | 1.49 ft | 0.97 ft | 0.95 ft |
| Sun, Oct 25 15:00 | 1.56 ft | 1.05 ft | 1.03 ft |
Measured heights from NOAA CO-OPS station 8761724, preliminary, above mean lower low water. The print carries the computed curve only: one year, no weather.