[api.met.no] Change in CAP alerts for Norway + some FAQs

[api.met.no mailing list]

Dear API users,

For users in Norway we would like to inform about a change in the CAP 
output used on MetAlerts regarding icy driving conditions. The 
eventCode  "drivingConditions" will be replaced by the more specific 
"ice" and "blowingSnow" eventCodes. More information here (in Norwegian):

https://www.met.no/nyhetsarkiv/farevarsling-av-is-og-snofokk-erstattar-vanskelege-koyretilhove

At the same time we would like to address a few common questions, as 
well as correct an error in the previous mail.


Locationforecast
----------------

The new model output available under /test is nearing completion, and we 
do not anticipate any further changes before going into production at 
the end of the month. During the test period we've made some minor 
changes and fixed some bugs, here's a quick summary:

- the model name is now called met_public_forecast instead of FORTI
- the global model is now updated every 6 hours instead of 12
   (not 3 instead of 6 as stated in the previous email)
- "runended" and "nextrun" has had some bugfixes and now work as in
   the old (current) version

Example:

https://api.met.no/weatherapi/locationforecast/1.9/test?lat=60.10&lon=9.58&msl=70


Q. Until now I have been looking at the 'runended' parameter to tell me 
when the forecast model was last updated (i.e. how "fresh" the forecast 
is). How do I find out when the underlying forecast model was updated 
for the received data?

A. The "runended" parameter is only meaningful when comparing two 
different forecasts for the same location (the newer one hopefully being 
more correct). To find out when to download newer versions, use the 
"nextrun" parameter.

Note however that the "nextrun" timestamp is *not* an exact promise, but 
an approximate guess of when the next model will be ready (variable 
depending on supercomputer load) plus a random delay to allow for model 
copying latency, XML caching timeouts etc.

Q. Why can't I just add a constant time interval to the "runended" 
parameter?

A. In addition to the reasons above, the model update periods for the 
various areas is expected to change without notice as we get more data 
and constantly try to improve the product. When the model update 
frequency increases, this will be reflected in the "nextrun" parameter.

Q. Are historical weather forecasts available via the api?

A. Unfortunately no, as the sheer amount of data makes it impossible. 
Our Nordic model run data are available as NetCDF files as described in 
the API documentation. Unfortunately we cannot distribute global models 
due to licensing issues.


Radar animations
----------------

Q. Will the GIF animations be discontinued at the start of 2020? What 
about the Javascript slideshow?

A. We are looking into the possibility of open-sourcing the timeslider 
library from gaf.met.no and other sites, but it is not trivial to 
decouple from React and other dependencies. For this we need to allocate 
more resources, but at the moment our hands are full migrating over 
legacy systems and hardware. As such there is no firm date when we will 
stop producing GIF radar animations.

Best regards,

Geir Aalberg
API developer