NOAA TidesAndCurrents provider

[alexbk66]

Ver 4.0.5.12 - Added NOAA TidesAndCurrents provider.
Ver 4.0.5.14 - TidesAndCurrents added Tides array.
Ver 4.0.5.44 - Added Currents (no forecast/predictions yet)

Please note, there's a lot of data and different formats available (i.e. MHHW, MLLW, MTL, MSL, etc. https://tidesandcurrents.noaa.gov/datum_options.html)

Since that's not my area of expertise, I will need expert users input on what and how you want to display.

The available data is also specific for the selected station. I provide the link to the station webpage (see the screenshot) - so you can check what's available.

Also, there's the data Inventory page for the station (i.e. https://tidesandcurrents.noaa.gov/in...tml?id=8723214), see the second screenshot.

[alexbk66]

Station selection

NOOA has different stations for Tides (Water Level) and Currents. Also some stations provide real time readings, other stations provide only forecast (predictions):

Tides measuring stations	https://tidesandcurrents.noaa.gov/st...e=Water+Levels
Tides prediction stations	https://tidesandcurrents.noaa.gov/tide_predictions.html
Currents measuring stations	https://tidesandcurrents.noaa.gov/cd...&filter=active
Currents prediction stations	https://tidesandcurrents.noaa.gov/noaacurrents/Regions

Please note that not every prediction station provides current measurements. So you might need to create two separate Locations and select different stations - one for current readings, one for predictions.

Here's some explanation from NOAA's Center for Operational Oceanographic Products and Services (Oceanographer Todd Ehret):

Maybe I need to explain that the "type of list" will also provide an indication of the type of data / information which is available for stations in that list.

A couple examples:

• A list of "active" currents stations (which would include cb0102 Cape Henry LB 2CH).
  • That would indicate that recent observational data for the station would be available
  • Unless the station is not presently operating correctly.
• A list of "current prediction" stations (which would include ACT3556 East Rockaway Inlet)
  • Indicates that tidal current predictions can be generated for the station.

Predictions and Observational data are two completely separate data types.

- Observational data is a measured data point, collected by a sensor installed at the site.

- Predictions are a mathematical calculation of the expected tides / currents conditions which would be experienced at the location; based solely on the positions / relative motions of the Moon, Earth, and Sun.

Most operating stations will appear in both the list of active stations, and the list of prediction stations.
Indicating that both types of data are available.
But the vast majority of the prediction stations listing WILL NOT have recent observed data.

If you are identifying a station from one list (i.e. the list of current prediction stations which ACT3556 is found in); you can only assume that that type of data (current predictions) is available for that station.

And more on Currents:

Data is collected every 6 minutes. That 6-minute data point is actually calculated based on a time period of +/- 3 minutes from the time stamp.

Example: the data point at 8:30am is actually an average of data collected from 8:27am-8:33am.

The data is transmitted within 1-4 minutes of that calculation being completed.

There is a delay from when the data is transmitted to when it is ingested into our database, allowing for a QA/Q crosscheck.

-- "bounceback" communication of the data back to the station for a confirmation of data being received correctly.

If the crosscheck is not good, the data is transmitted again from the station with the next 6-minute data package.

This crosscheck and bounceback check repeats until a clean data value is received; or 30 minutes from the original data collection has passed.



The "date=latest" only returns the last 18 minutes of data.. dated from the time stamp when it is received
Example: 8:32am would only return data from 8:14-8:32. That is only 3 data points... actually only 2 - 8:18, 8:24, as that the 8:30 data is not yet completed calculations.
If there were issues with the QA/QC of the data / transmission, it is very possible that those 2 data points may not be available.
Which would result in the error message you receive -- no data points in the database from the last 18 minutes.

Currents station, especially buoy mounted stations, are more susceptible to this kind of problem.

Currents station cb0102 Cape Henry LB 2CH - is attached to a buoy (lighted buoy 2CH).
Buoys bounce, and rock; passage of large commercial ships nearby; bad weather conditions; can all block or interfere with the radio communications from the buoy station.
It is not uncommon for the data to be 1-2 data packages "behind".
Which, depending on the timing of the "date=latest" request, could return the error message as no data for that 18 minute time window is available.

We make a "date=latest" option available for the API; and for shore-mounted stations there is usually data available in that 18-minute window.
But for buoy mounted stations, there is no guarantee that it will work as you expect.
All water level stations are shore mounted, only some currents stations are shore mounted.

I do not know what your application is, or what you are attempting to provide.


But are you sure that you absolutely need the data from only the past 18 minutes?

And are you prepared to handle the issues when there isn't data from that short time period?

Or maybe, a better option would be to get data from a longer time period - to more ensure that at least some data is returned.

- date=today (24 hours staring at midnight)

- date = recent (past 72 hours)

- or use a begin date / end date combination with time ([COLOR=#333333 !important]yyyyMMdd HH:mm) to get the last hour of data. [/COLOR]

[racerfern]

I'm curious, besides NOAA, what agency maintains tides and currents? I ask because my area, the south shore of western Long Island, NY doesn't have any NOAA points near me. However, there are numerous "official" tide stations around here.

[alexbk66]

If you click on any station at https://tidesandcurrents.noaa.gov/ma...999994&zoom=10 and then click on "Station Home" - you can see details, they mention Center for Operational Oceanographic Products and Services (CO-OPS)

[racerfern]

OK, CO-OPS shows my local station as ID 8516411 https://tidesandcurrents.noaa.gov/st...tml?id=8516411
But I can't put that number in, I can only select the "main" stations.

[alexbk66]

OK, CO-OPS shows my local station as ID 8516411 https://tidesandcurrents.noaa.gov/st...tml?id=8516411
But I can't put that number in, I can only select the "main" stations.

You can enter the station ID manually and it does report tides predictions, but not any other data.

[racerfern]

Very nice with the array, thanks! However, the "link" shows the default list rather than my custom local tide chart.
Although clicking the link takes you to my local station. I would just like the name to display correctly.

[alexbk66]

Do you mean the name of the station in the link should be "Freeport, Baldwin Bay"? Yes, I get the station names from the list of major stations, which doesn't include 8516411. I need to work out how to get the correct station info, they do have Metadata API. In the worst case I will just show station ID without the name.

[alexbk66]

BTW, you can delete the "Unknown" devices, they shouldn't be re-created until the data becomes available.

[alexbk66]

racerfern as a workaround, you can manually add your station to "C:\Program Files (x86)\HomeSeer HS4\Data\AKWeather\co-ops_stations.json".

Note, it will be overwritten when you update the plugin, so save a copy.

[EDIT]

I also save a cached file for your particular coordinates with distance from your location for each station (i.e. co-ops_stations_25.5722_-80.2321.json) which I use instead of the original file (until you modify your lat/lon). You can (should) delete all these if you modify the original file.

[alexbk66]

Ver 4.0.5.15 - TidesAndCurrents improved manual station ID config

I also added "Freeport, Baldwin Bay" to the co-ops_stations.json

[alexbk66]

racerfern I have a reply from Co-ops userservices explaining why Station 8516411 Freeport, Baldwin Bay, NY isn't listed:

Water Level Station 8516411 Freeport, Baldwin Bay, NY is a tide prediction station
-- it is NOT presently operating, and thus will not appear in the specific "list of stations" you refer to.
-- it is a historical station, last observed for 1 month in 1934. Those data have never been digitized, thus it will not appear in a list of stations with electronic historical data.
-- The only data / product / service available for this station is tide predictions; thus it will only ever appear in a list of the tide prediction stations.

Which "list of stations" are you referring to?

The list of stations which are operating / providing data in real time? (about 300 stations)
The list of stations which have electronic historical data, most of which are no longer operating? (about 2500 stations)
The list of stations which have tidal datums? (about 1800 stations)
The list of stations which have benchmark sheets? (about 1800 stations)
The list of stations which offer tide predictions (about 3500 stations)

[racerfern]

alexbk66 WOW! Thanks for the info. The only thing I use from that station is tide data so all's well.

[will40]

Hi Alex

This look's good. I just added this to my marine forecast and devices. As a feature request would it be possible to have a device for current or upcoming tide? For example a device such as

Next tide is: High @ 12:28PM or Next tide is: Low @ 6:17AM

Or even a High Tide and Low Tide device with the times. I like to display these values on my mobile.

I see the Tide [] devices now as behind, next, and look ahead but I was hoping for a way not to have to figure out the current time of day and scrape the time from the tide elevations from the device status's.

Thanks

[racerfern]

will40 My local tide shows as below. What does yours show?