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GOES-West Satellite Imagery Is Not Radar

GOES-West is a geostationary satellite, not radar. Infrared and water-vapor imagery from current GOES-18, with historical West-slot context.

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The historical path is /radar/noaagoeswest. The subject is not radar. GOES-West is a geostationary weather satellite: it stares at the Western Hemisphere from a fixed longitude and records radiance in visible, infrared, and water-vapor channels. Those pictures are remote sensing of the atmosphere from orbit. They are not WSR-88D reflectivity, not a rain gauge, and not a current loop of a 2005 JPEG. This article keeps the old URL and states the distinction in the first heading so a backlink does not train a search engine to treat GOES as NEXRAD.

TNET Weather does not rehost GOES captures. For current official imagery, use NOAA NESDIS viewers such as the GOES Imagery Viewer. TNET is not a warning service.

Historical context

Personal weather sites routinely filed satellite thumbnails under a “Radar” menu because the public word for “animated weather picture” was radar. The TNET Weather page named NOAA GOES-West explicitly. That was the right satellite family and the wrong parent folder. Operators wanted infrared and water-vapor loops for the western United States and the eastern Pacific—cloud-top temperature and mid- to upper-level moisture—beside the station table. Any GRLevel3 or Weather Underground still that once appeared under this slug is a historical image, valid only at its stamped time. It is not today’s GOES-West.

Geostationary viewing versus a radar volume

A WSR-88D is a ground radar. It pulses microwaves, builds a volume of elevation scans, and maps returned power and Doppler motion in a polar coordinate system centered on an antenna. GOES-West does none of that. It is an imager in geostationary orbit, looking down at a wide disk. NOAA operates a GOES-East and a GOES-West spacecraft so the Atlantic and Pacific approaches to North America stay in view. CLASS documentation places the historical West slot near 135°W; the current GOES-R series West location is documented by NESDIS near 137.2°W.

Consequences for a PWS caption:

  • A satellite pixel is a line-of-sight radiance (or a brightness temperature derived from it), not a rain rate at the ground.
  • Parallax shifts high clouds away from their true Earth location, especially at the edge of the disk. Radar range rings do not apply.
  • Night kills ordinary visible channels; infrared continues. Water-vapor channels are infrared measurements of moisture-sensitive wavelengths, not photographs of steam.
  • Update cadence is a scan schedule (minutes), not a NEXRAD volume coverage pattern.

If a page stacks a GOES frame above a radar frame, that is juxtaposition. It is not a fused “sat-radar” observation unless a documented algorithm produced a derived product and the caption says so.

Current GOES-West: GOES-18

As of the last check on 13 August 2026, NOAA NESDIS identifies GOES-18 as the operational GOES-West satellite. NESDIS’s GOES-18 mission pages describe GOES-T launching on 1 March 2022, receiving the GOES-18 name on reaching geostationary orbit, and entering operational service as GOES-West in January 2023, replacing GOES-17. A NESDIS news item dated 4 August 2026 still labels GOES West as GOES-18 while discussing Pacific Northwest smoke, which is current public confirmation of that assignment at writing time.

GOES-18 carries the GOES-R series Advanced Baseline Imager (ABI): sixteen spectral bands, including visible, near-infrared, infrared window, and water-vapor channels, at higher refresh and spatial resolution than the previous GOES imager generation. GeoColor and other RGB composites are derived displays from those bands. They are easier to look at; they are not an extra satellite.

This page does not claim GOES-18 is the reader’s serving communications satellite, and it does not claim ABI cloud fraction sets a Starlink speed. Those would mix Earth-observation spacecraft with a broadband constellation and then leap from clouds to throughput. TNET does not make that leap.

Infrared and water vapor on a station page

Infrared window channels respond to brightness temperature. Cold, high cloud tops are bright in the usual IR enhancement; clear air and warm low clouds are darker. IR is available day and night. It does not measure rainfall. Thick cold tops often accompany deep convection, but the pixel is still temperature (or radiance), not dBZ and not gauge depth.

Water-vapor channels are sensitive to water vapor in a broad layer of the middle and upper troposphere (the exact weighting depends on band and atmosphere). Dry slots, plumes, and the outlines of upper-level waves show up here even when the infrared window looks relatively clear. A water-vapor image is still not radar, and it is not a surface humidity sensor. The station hygrometer remains the in-situ moisture observation.

Visible channels show reflected sunlight: cloud texture, smoke, and snow. They are daytime only. They are not lightning and not a webcam.

A responsible PWS panel lists satellite name (GOES-West / GOES-18), channel or product, sector, and time in UTC. It links to NESDIS rather than caching a crop that will outlive its legend. Combining those frames with lightning detections is treated on lightning detection versus satellite imagery.

Historical West-slot spacecraft (without a recovered TNET archive)

Hobby pages from the GOES-I/M and GOES-N/P era did not see GOES-18. NOAA CLASS lists successive spacecraft at 135°W, the classical West longitude:

  • GOES-10: operational interval in CLASS from 21 July 1998 to 21 June 2006 at 135°W.
  • GOES-11: operational interval in CLASS from 21 June 2006 to 6 December 2011 at 135°W.
  • GOES-15: operational interval in CLASS from 2 August 2011 to 2 March 2020 at 135°W.

Those rows identify which imager occupied the West slot in which years. They are not a claim that a particular TNET thumbnail came from a particular spacecraft unless the file itself named it. OSPO’s decommissioned-satellite notes record later end-of-mission dates for some vehicles after they left the operational West role. This article does not invent handover hours beyond CLASS. If you have an old “GOES-West IR” GIF, treat it as historical radiance from whatever West spacecraft was operating at the stamp on the image, not as GOES-18.

GOES-17 served as GOES-West after GOES-15 and before GOES-18; NESDIS documents GOES-18’s replacement of GOES-17 in January 2023. Fine operational overlap is NOAA’s history, not a PWS loop.

Do not file satellite under radar without a label

Practical rules for a weather site that inherited a /radar/ URL for GOES:

  1. The H1 or the first sentence must say satellite, not Doppler.
  2. Do not put GOES frames on a dBZ color bar.
  3. Do not animate a 2009 water-vapor still and call it live.
  4. Do not treat cloud cover as a rain observation or as a Starlink outage log.
  5. Point “current view” at NESDIS GOES imagery or the GOES-West PACUS sector.
  6. Keep radar science on /radar and Level III clients on /radar/grlevel3.

Modern relevance

Cloud structure, atmospheric water, and storm morphology are weather evidence. TNET groups those atmospheric inputs on evidence families. The Horizon study review discusses relationships among atmospheric conditions and Starlink performance at a research level. That review is conceptual context. It is not a result that “GOES IR brightness temperature reduces download speed,” and TNET does not claim clouds alone determine a connection outcome.

Observed ABI radiance, modelled moisture fields, and any derived connection outlook stay labeled on how the service works. A dated planning estimate for a city and interval is the Connection Outlook—not a satellite loop and not a warning.

Historical observation pages: observations hub.

Sources