How fresh is the data and when does it update?

The instrument fetches the forecast when you open it and again when you change the place, and it fetches observations on the same occasions. The ensemble is fetched again when you change the height or limit. It does not poll in the background, so a tab left open all morning keeps showing what it loaded. The service also lets its forecast answer be reused for about 10 minutes, the ensemble for about 15 and observations for about 10, so reloading twice in quick succession may show the same numbers. The upstream weather models themselves produce new forecast runs on their own schedules, a few times a day, so a new fetch will only differ from the last when a newer run or station report exists.

Observations are measurements, not forecasts. The instrument looks for the nearest METAR or buoy within 150 km, shows how many minutes old the report is and, in the ember colour, adds STALE when it is over 90 minutes old. The Obs age tick on the Agreement Spine turns weak or failing when reports are old. If nothing usable is in range, you see OBSERVATION UNKNOWN with the reason. A missing value is shown as UNKNOWN and never as calm. See UNKNOWN and missing data and observations against the model.

Cab mode reads the last packet the instrument stored on this device. It shows it straight away, then refreshes automatically if you are online. The banner says LIVE with the time when the refresh worked, or CACHED and not live with a status such as Offline, Refreshing… or Refresh failed followed by the reason. If the saved forecast no longer reaches the current hour, Cab shows The cached forecast no longer covers this hour. with UNKNOWN and a prompt to refresh when you have signal. Cab cannot change place, height or limit, and it holds whatever the instrument last had. See how to use Cab mode.

The fleet board loads when you open it and when you press Refresh, and it re-reads a site when you save its rule. It does not poll. Its summary strip shows Updated with a UTC time. A live public board refetches every 10 minutes while open. When it cannot, it shows the last good reading with STALE · LAST GOOD PACKET. A board built from a frozen record never changes, and it gains a STALE badge after six hours simply to say that it is old. Alerts are separate again: the scan runs every 30 minutes. See embed a public board.

Lead time is how far ahead the hour you selected lies. The Lead time tick shows Lead and the hours, adds skill falling as the lead grows and beyond 72 h past three days. Forecasts get less certain with distance, so the same data is more reliable for tomorrow than for next week. A chip on the map says AGREE or SPLIT with a count of models, and a split deserves a closer look at the ensemble fan. See when the models disagree.

If the whole forecast fails, the instrument shows The forecast did not load. with the error and a Retry button instead of numbers. Check your connection first, press Retry and then reload. If observations or the ensemble fail on their own, the instrument still shows the forecast and marks the missing part as UNKNOWN or unavailable. If this keeps happening, use the /contact page and include the message and the place. For sources see where the data comes from.