TGFTP doesn't carry the 5-minute HFMETAR data as far as I can tell, but even
when it is available there are issues with some of its data due to rounding and
averaging periods.
https://mesonet.agron.iastate.edu/onsite/news.phtml?id=1290
Synoptic does have 1-minute METAR available.
https://docs.synopticdata.com/services/high-frequency-asos
With a status page showing timeliness:
https://demos.synopticdata.com/hf-asos-available/index.html
Rob
________________________________
From: ldm-users <ldm-users-bounces@xxxxxxxxxxxxxxxx> on behalf of Gregory
Grosshans <gregory.grosshans@xxxxxxxx>
Sent: Tuesday, March 17, 2026 1:15 PM
To: Thomas B <thms_brgg@xxxxxxxxx>
Cc: Charles Concodora <concodcw@xxxxxxxxxxxxxxxxx>; ldm-users@xxxxxxxxxxxxxxxx
<ldm-users@xxxxxxxxxxxxxxxx>
Subject: Re: [ldm-users] Looking for upstream IDD feed for personal METAR
research project
At a high level the flow of METAR data from ASOS sites at U.S. Airports
traverse the FAA networks to the NWS NWSTG/GATEWAY system. Once at
NWSTG/GATEWAY, essentially, the data is sent to
TGFTP.nws.noaa.gov<http://TGFTP.nws.noaa.gov> as well as to the NCF, where the
NCF uplinks the data to the SBN/NOAAPORT. UNIDATA and other top-tier LDM/IDD
sites with an SBN/NOAAPORT ingest system will receive METAR data from the
SBN/NOAAPORT and inject it into the LDM/IDD network. Returning to the
NWSTG/GATEWAY, they also send METAR data to other WMO member countries at the
same time they send the data to TGFTP and NCF.
MADIS is different from the NWSTG/GATEWAY. Note MADIS originated on the
research side of NOAA (i.e. OAR ESRL/GSD per your weblink) and then a version
became operational at NWS/NCEP many years ago. MADIS also collected various
mesonets. From my understanding MADIS is no longer being developed, instead
the NWS is utilizing SynopticData <https://synopticdata.com/> to acquire the
various mesonets. I understand SynopticData also connects with the FAA to
acquire observational data via a special agreement. You would have to check
with the FAA (and I'm not sure who it would be) to see if other private sector
companies connect to the FAA to receive METAR data.
I suspect the lowest latency will be obtaining data from TGFTP, followed by an
LDM feed from the IDD.
Some weather enthusiasts repurpose old satellite dishes from the 1980s or
1990s, originally used for satellite TV, for their own SBN/NOAAPORT satellite
ingest systems. This includes buying a NOVRA box, computer, etc to ingest the
data from the dish. This is an option to obtain METAR data from the SBN and it
would be slightly faster than the latency introduced by the IDD (which is
likely only a few seconds faster depending on how close your connection is to a
top-tier site). You could also set up a smaller satellite dish (compared to
the SBN/NOAAPORT dish) and use the Emergency Managers Weather Information
Network (EMWIN), which is supposed to include METAR observations. I suspect
the route of METAR data for EMWIN goes from NWSTG/GATEWAY -> NESDIS -> GOES
EAST/WEST satellites. Also, I believe there is a terrestrial based EMWIN
server if you don't want to set up a satellite ingest system.
Gregg
On Tue, Mar 17, 2026 at 10:06 AM Thomas B
<thms_brgg@xxxxxxxxx<mailto:thms_brgg@xxxxxxxxx>> wrote:
Hi,
Thanks for the pointer to tgftp.nws.noaa.gov<http://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<mailto: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<mailto:thms_brgg@xxxxxxxxx>> wrote:
tgftp.nws.noaa.gov<http://tgftp.nws.noaa.gov/>
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