User Guide›Station distance

Station distance

The reporting station is the nearest one with a METAR or TAF — and how far away it is is the single most important caveat on every adjusted number.

Its distance and direction from your facility are shown on each block (e.g. "12.3 nm SE"). Distance matters here more than almost anything else, because the whole adjustment rests on an assumption that gets weaker the farther away the station is: that the cloud deck holds flat and level all the way from the station to your facility. It doesn't, exactly — decks slope, break up, and change with terrain — and the more ground that assumption has to cover, the less it holds.

The two lines the tool draws

10 nm or more — the distance turns orange, and an orange banner appears above the adjusted figures: CAUTION: WX STATION >10NM FROM FACILITY.
More than 15 nm — the distance turns red, and the banner escalates to WARNING: WX STATION >15NM FROM FACILITY.

In both cases the banner is attached to the figures it qualifies — same colored border, no gap between them — so the estimate and its caveat are one object on the page, not two things you might read separately. Only one banner appears at a time: past 15 nm the red warning replaces the orange caution rather than stacking on it.

In grid view A facility with a station beyond 15 nm shows only the banner — WX >15NM AWAY — in place of its visibility and cloud rows, and its box carries no flag color. This is deliberate: the grid exists to be scanned in seconds, and a number in a grid box gets read at a glance, caveat or not. At that range the tool won't put one there. Open the box for the full estimate with the warning attached. (The 10 nm caution has no grid banner — the distance still turns orange, and the conditions show as normal.)

The reasoning behind both lines is the same. An adjusted height is only as good as the assumption that the deck holds level between the station and your facility, and that assumption gets thinner with every mile. Past 15 nm the number is still worth having — you can reason about it, weigh it against what you see, and decide — but it should never be mistaken for an observation of your site. So the tool keeps it, and makes the warning impossible to miss.

Note that the METAR and the TAF can come from different stations at different distances. Each block is judged on its own station, so it's entirely possible to see a clean estimate on one side and a banner on the other.

The search stops at 50 nm. If the nearest reporting station is farther than that, the tool shows "No METAR station found nearby" (or the same for the TAF) rather than adjusting a station so distant the estimate would mean little — well past the 15 nm warning line, a deck-holds-level assumption stretched that far tells you almost nothing about your site.

When weather can't be loaded

That message means a station genuinely isn't in range. It is different from aviationweather.gov being briefly unreachable — and the tool tells the two apart rather than reporting both the same way.

If a report is missing because the upstream fetch failed, a notice appears above the results saying so, and the tool retries once automatically. If the retry succeeds the data fills in and the notice disappears. If it fails again the notice stays, with a Try again button, so a temporary outage is never left looking like an answer.

Nothing is retried when a station simply isn't there. Many sites report a METAR but never issue a TAF, and a facility can sit beyond the 50 nm cutoff — in those cases the plain "found nearby" wording stands on its own, because retrying would only imply data might appear when none exists.

See also How it works for the adjustment itself, and List, Grid & Map for how the grid handles distant stations.