How do I compare observations with the model?
Read the observation line in the inspector: a real METAR or buoy report set beside what the model said for 10 m at the same hour, with its age and distance, so you can judge how far to trust the forecast.
ON THIS PAGE
Steps
Open the instrument
Go to /app and pick your place. Below the exceedance fan, and above the row of model chips, the inspector shows one observation line. On a phone it sits in the bottom sheet; drag the handle up to see it.
Read the observation line
The first line reads like "METAR EIWF 18 min · 6.9 mph · 270° · model 10 m was 7.1". That is the station type and identifier, how many minutes old the report is, the measured speed in your display unit, the direction, and the 10 m model speed for the same hour. A buoy shows "BUOY" and a wave height with period, for example "Hs 1.8 m / 7 s".
Read the second line
Underneath, in smaller type, you get the station name, its distance in kilometres from your pin, and the height above ground the instrument was reading at, shown as "10 m AGL" for example. If the report is old the word STALE is added and the line turns ember coloured.
Check the Obs age tick
On the agreement spine the first tick is "Obs age". Hover it, or tap it on a touch screen, to read its detail. A filled tick means the report is 30 minutes old or less, a hollow tick means up to 90 minutes, and an ember tick means older than 90 minutes, flagged stale, or no station found.
Compare measured with modelled
Set the observed speed against "model 10 m was". A close match says the model has this place about right for now. A gap is a prompt to look harder, not an instruction. Compare at 10 m even if your working height is higher, because that is the level the station measures.
Tip: Hover the observation line to see the raw METAR text in the tooltip.
01What the observation line is
The observation line is a comparison, not a forecast. It takes the nearest usable weather report and places it beside the model value for the same hour at 10 m. The point is to answer one question: is the model, right now, close to what a real instrument is reading near here? It appears in the inspector on /app, and the agent can quote the same figures when you ask it about the observation.
02Where the reports come from
There are two kinds of station. METAR reports come from airports and are made for aviation; they carry mean wind speed, direction, and sometimes gusts. Buoys come from the NDBC network and add wave height and period alongside wind. The instrument searches within 150 km of your pin and takes the closest usable station. If you set the Marine persona, buoys are preferred over airport reports when one is available. Neither network belongs to The Wind Agent; we read what they publish.
03Age, and when a report goes stale
Every report carries an age in minutes. The line prints it, and the Obs age tick grades it: 30 minutes or less is good, up to 90 minutes is weak, and beyond 90 minutes the report is treated as stale. A stale report still displays, but in ember with STALE added, because a wind that was true an hour and a half ago may not be true now. Where a station stops reporting altogether, the age simply keeps growing.
04Why the comparison is at 10 m
Stations measure close to the surface, normally at 10 m for airport reports. The instrument compares that reading with the 10 m model value for the same hour, which is the fairest like-for-like pairing. Your working height can differ. If you are working at 80 m, the observation tells you how the model is doing near the ground and says nothing direct about 80 m. For how the figure changes with height, see the height article linked below.
05When there is no observation
If no usable METAR or buoy lies within 150 km, the line reads "OBSERVATION UNKNOWN · no usable METAR or buoy within 150 km". If the station request itself fails, it reads "OBSERVATION UNKNOWN · stations unavailable" with the reason. While the lookup is running you see "Reading METAR and buoy stations…". In every case the Obs age tick goes ember. Unknown is not calm: it means there is nothing to compare against, so lean on the model, the ensemble and your own eyes.
06When the two disagree
Disagreement is normal. A station may sit in a sheltered valley or on a headland, the model is an average over a grid square, and a single reading can be a lull or a gust. Look at three things together: the size of the gap, the age, and the distance. A fresh report from a station a few kilometres away that disagrees sharply with the model deserves attention. An old report from 120 km away deserves much less. If the map chip also says SPLIT, the deterministic models disagree among themselves as well, which is a separate signal.
07What the observation does not do
The observation does not change the hero number, the lamp, the exceedance odds or any alert. Those come from the forecast, the ensemble and your limit. The observation is there so that you can judge them. It is also not a measurement at your site unless your site happens to be at the station. Modelled forecast, not an observation of your location: that wording on the page is deliberate.
Questions
What height is the observation measured at?
The second line of the observation shows the station height above ground, such as 10 m AGL for an airport report. That is the height of the instrument, not your working height. The model figure printed beside it is always the 10 m level, so the pair is a like-for-like comparison at the surface.
Why does the line say OBSERVATION UNKNOWN?
The instrument found no usable METAR or buoy within 150 km of your pin, or the station service did not answer. The line stays on screen and says so rather than disappearing. Try moving the pin toward a coast or an airport, or wait and reload. Meanwhile treat the observation as unknown and rely on the forecast and ensemble.
What does STALE mean here?
A report is stale when the station data is flagged stale or when it is more than 90 minutes old. The line turns ember and shows STALE after the distance and height. It is still shown so that you can see how old it is, but you should give it little weight.
Can I trust the model if it disagrees with the station?
Treat it as a reason to look closer. Check the age and the distance first. A fresh, nearby report that differs from the model suggests local conditions are not matching the forecast. The call remains yours; the instrument shows its working and does not decide for you.
Does the observation change the wind number at the top?
No. The hero number is modelled wind at your height, and the lamp compares it with your limit. The observation is shown beside them for comparison only, and it does not feed the odds or the alerts.