Tidalwater

NAME

Tidalwater - Tidal water information

DESCRIPTION

Water level forecast for a selected set of harbors in Norway. Weather condition adjustments are generally available for the immediate three days, in 10 min resolution. The files are updated 1-2 times per hour.

OUTPUT FORMAT

Data is delivered as a fixed-column plaintext file. Values are given as meters above mean sea level (middelvannstand), and all times are in UTC.

Water level have two components: Tidal forces (TIDE) and the influence of weather (SURGE). Tidal forces is the basis for calculating water level. Forecast of weather conditions for the specified harbor is then used to adjust this basis (TOTAL). Waves are not included in the forecast, only long period phenomena.

See https://kartverket.no/sehavniva/data-pa-se-havniva/viktige-vannstandsniva/ for further information on the reference water level.

Columns

AAR, MND, DAG, TIM, MIN

Year, month, day, hour and minutes (in UTC) respectively

PROG (deleted)

Prognosis length (time since model run)

SURGE

Influence of weather (wind, air pressure)

TIDE

Tidal forces (astronomical data from Kartverket)

TOTAL

Total water level (sum of SURGE and TIDE)

0p, 25p, 50p, 75p, 100p

Percentiles of SURGE, i.e. how many of the ensemble forecasts are below the indicated (absolute) value. E.g. if 75p is 0.14, this means 75% of the forecasts are below 0.14 while 25% are more than that.

Example output (Bergen harbor)

    MET - PROGNOSER

    VANNSTANDSVARSEL --- MET STORMFLO ---

    SIST OPPDATERT: 20241025 08:55 UTC
    ==========================================
    BERGEN
    ------------------------------
     AAR MND DAG TIM MIN  SURGE  TIDE   TOTAL  0p     25p    50p    75p    100p
    2024  10  24  12   0   0.09   0.17   0.26   0.04   0.09   0.09   0.09   0.14
    2024  10  24  12  10   0.09   0.19   0.28   0.04   0.09   0.09   0.09   0.14
    2024  10  24  12  20   0.10   0.21   0.31   0.04   0.09   0.10   0.10   0.15
    2024  10  24  12  30   0.09   0.23   0.32   0.04   0.09   0.09   0.09   0.14
    2024  10  24  12  40   0.10   0.25   0.35   0.05   0.09   0.10   0.10   0.15
    2024  10  24  12  50   0.11   0.26   0.37   0.06   0.11   0.11   0.11   0.16
    2024  10  24  13   0   0.11   0.28   0.39   0.06   0.10   0.10   0.10   0.16
    2024  10  24  13  10   0.10   0.30   0.40   0.05   0.09   0.09   0.10   0.16
    2024  10  24  13  20   0.11   0.32   0.43   0.06   0.09   0.09   0.10   0.16
    2024  10  24  13  30   0.11   0.34   0.45   0.06   0.10   0.10   0.10   0.16
    2024  10  24  13  40   0.11   0.36   0.47   0.06   0.10   0.10   0.10   0.16
    2024  10  24  13  50   0.11   0.38   0.49   0.06   0.10   0.10   0.11   0.16
    2024  10  24  14   0   0.11   0.39   0.50   0.06   0.10   0.10   0.10   0.16
    2024  10  24  14  10   0.12   0.40   0.52   0.06   0.10   0.10   0.10   0.17
    2024  10  24  14  20   0.11   0.41   0.52   0.06   0.10   0.10   0.11   0.17
    2024  10  24  14  30   0.12   0.42   0.54   0.07   0.10   0.10   0.11   0.17

Available

Available is implemented at https://api.met.no/weatherapi/tidalwater/1.1/available which lists all harbors which we have forecasts for.

Parameters

A request must specify the harbour of interest. Datatype and content-type are optional.

harbor (mandatory)

Specify the harbor of interest.

Available harbors:

andenes, bergen, bodø, bruravik, hammerfest, harstad, heimsjø, helgeroa, honningsvåg, kabelvåg, kristiansund, leirvik, mausund, måløy, narvik, ny-ålesund, oscarsborg, oslo, rørvik, sandnes, sirevåg, solumstrand, stavanger, tregde, tromsø, trondheim, træna, vardø, viker, ålesund

content_type (optional)

Specify content type for the returned data.

Currently only valid value is text/plain (default), so can be ignored

datatype (optional)

Specify type of data, currently only valid value is weathercorrection (default), so can be ignored

Example requests

    https://api.met.no/weatherapi/tidalwater/1.1/?harbor=bergen

    https://api.met.no/weatherapi/tidalwater/1.1/?harbor=trondheim&content_type=text/plain&datatype=weathercorrection

Changelog

Output format change

Resolution increased from 1 hour to 10 minutes.

The column "PROG" (prognosis length, i.e. time since model run) har been replaced with "MIN", showing minutes of the hour.

New harbour Sandnes, 2022-10-06

Data for Sandnes added to harbour list

Documentation errata, 2020-03-30

Corrected to say that levels are in meters (not centimeters as previously stated) and times in UTC, as well as explanations of the percentile columns.

New harbour Mausund, 2020-02-05

Data for Mausund added to harbour list

1.1 2018-07-04

Available implemented, only harbor is now a mandatory parameter

1.1 2013-01-28

- weather correction data is changed
- old product like tidal is removed

1.1 2008-02-25

  • New version 1.1 available
  • Changed name of parameter: type => datatype.
  • Parameter datatype is now mandatory.
  • Access to tidal data has been restricted.
  • Old version, 1.0, expires 1.april 2008.
 

Changelog