News and Notes

One of the seemingly unique archives maintained by the IEM is one of NWS Terminal Aerodome Forecasts (TAF)s. An example TAF looks like so:

FTUS42 KFFC 131551 AAB
TAFATL
TAF AMD
KATL 131551Z 1316/1418 09007KT P6SM FEW250
     FM140000 12003KT P6SM SCT250
     FM141600 14005KT P6SM SCT150=

A user of this archive requested the tracking of "Amendment" status, which the IEM was previously not doing. In the example above, this is denoted as TAF AMD. Support for this was added, but it will take a few days to reprocess the archive to include this attribute within the download service and various web services. Whilst adding web service support for this, the taf overview got some interesting updates and this news item intends to advertise those changes.

Newly supported TAF overview request examples

Provide GeoJSON of all most recently issued TAFs valid at 12 UTC on 25 Dec 2025
https://mesonet.agron.iastate.edu/api/1/nws/taf_overview.geojson?at=2025-12-25T12:00:00Z
This would return the most current issued TAF at or prior to the given UTC timestamp.

Provide JSON of available TAFs for Des Moines during July 2012.
https://mesonet.agron.iastate.edu/api/1/nws/taf_overview.json?station=KDSM&sts=2012-07-01&ets=2012-08-01
This returns all TAF metadata that can be used for subsequent queries to get an individual TAF.

Provide a CSV of all available TAFs for 15 December 2021 (UTC)
https://mesonet.agron.iastate.edu/api/1/nws/taf_overview.txt?sts=2021-12-15&ets=2021-12-16
Requests like these are limited to a 10 day period. The response seqnumber value orders the TAFs descending in time for a given station.

Hopefully folks find this useful and please always send bug reports and feedback our way!