NAME

Locationforecast - Weather forecast for a specified place

DESCRIPTION

This modules implements a full forecast for one location, that is, a forecast with several parameters for a nine-day period.

The parameters are temperature, wind speed, wind direction, pressure, precipitation, cloudiness, fog, lowClouds, mediumClouds, highClouds and humidity.

Since version 1.8 it will also have probability-elements for temperature, wind and symbol (norwegian locations only). A probability element specifies certainty of prognoses for a given parameter for a given time. This certainty is defined by a probabilitycode in the following manner:

    probabilitycode certainty values
    --------------- ----------------
           0        [90% , 100%]
           1        [50% ,  90%>
           2        [ 0% ,  50%>

Historical forecasts

While we only serve current forecasts via the API, you can find historical forecast model data in NetCDF format on http://thredds.met.no/thredds/metno.html.

Restrictions

The availability and content of this product may change without further notice.

USAGE

Parameters

lat

latitude in decimal degrees, mandatory

lon

longtitude in decimal degrees, mandatory

msl

whole meters above sea level (integers), optional. This option will only be used outside Norway. In Norway the height will always be taken from our own topographical model.

Sample request URLs

    https://aa025kn2jhfvzrxns.api.met.no/weatherapi/locationforecast/1.9/?lat=60.10&lon=9.58&msl=70
    https://aa025kn2jhfvzrxns.api.met.no/weatherapi/locationforecast/1.9/?lat=60.10&lon=9.58

Status

Operational status for each model can be checked like this:

    https://aa025kn2jhfvzrxns.api.met.no/weatherapi/locationforecast/1.9/status

Schema

The schema for the xml delivered by this product is available from https://aa025kn2jhfvzrxns.api.met.no/weatherapi/locationforecast/1.9/schema

FAQ

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.

CHANGELOG

New model backend: 2019-12-03

We are launching a new backend with a unified model. The XML output should identical in structure and validate against the existing schema, but may have some different time intervals.

The main differences are:

Should you experience any problems with the new backend, we suggest switching to LocationforecastLTS until you can make the necessary changes.

version 1.9 : 2014-05-20

phase out of version 1.5 : 2011-08-16

Version 1.5 of locationforecast will expire at 2011-10-01. Note that log entry below stating that version 1.5 will be available until version 1.9 is released is no longer correct.

version 1.8 : 2010-06-10

New attributes for the precipitation element: minvalue, maxvalue and probability. Note that these attributes will only be available for locations in a limited area in Europe. Longterm forecast/EC-data for norwegian locations will have fewer parameters available than version 1.5.

1.8 is meant as a transitional version, you may use 1.5 until we release version 1.9. Version 1.7 will be available until 2010-10-01.

version 1.7 : 2010-03-03

Precipitation and symbol values for the first time intervals have been missing in all earlier versions. This has now been corrected.

1.7 is meant as a transitional version, you may use 1.5 until we release version 1.8.

Version 1.6 will be available until 2010-09-01.

version 1.6 : 2009-01-15

1.6 is meant as a transitional version, meaning that you may use 1.5 until we release version 1.8.

version 1.5 : 2008-05-30

1.4 : 2007-12-03

1.3 : 2007-09-12

1.2 : 2007-06-15

1.1 : 2007-04-25

1.0 : 2007-05-15