Hi,
Thanks for the pointer to tgftp.nws.noaa.gov — I'm currently polling it and it
does seem to be one of the fastest publicly available HTTP sources for METAR.
However, from what I've been reading, tgftp serves static files that are
regenerated on a cycle (the MADIS documentation at
https://madis.ncep.noaa.gov/madis_metar.shtml mentions data is "processed every
5 minutes"). So even with aggressive polling, there's an inherent delay of up
to several minutes between the observation time and when it appears on tgftp.
By contrast, the LDM/IDD network distributes METAR via push as soon as it's
injected from NOAAPort/SBN. The LDM network troubleshooting docs
(https://docs.unidata.ucar.edu/ldm/current/troubleshooting/networkTrouble.html)
reference sub-second product latency as typical for well-connected IDD nodes.
For my use case, that difference matters a lot — I need the lowest possible
latency on METAR observations. So I'm really interested in getting an LDM feed
rather than polling tgftp.
I saw in the FAQ that non-academic users can sometimes arrange a feed from a
willing upstream participant.
Thanks again for your help.
Le lundi 16 mars 2026 à 22:26, Charles Concodora <concodcw@xxxxxxxxxxxxxxxxx> a
écrit :
> As far as I'm aware, [tgftp.nws.noaa.gov](http://tgftp.nws.noaa.gov/) has the
> lowest latency.
>
>> On Mar 15, 2026, at 2:30 PM, Thomas B <thms_brgg@xxxxxxxxx> wrote:
>>
>> [tgftp.nws.noaa.gov](http://tgftp.nws.noaa.gov/)