METARs usually update a few minutes before every hour. We check for update every 5 minutes.

Displayed status time is time of most recent data update

TAFs are routinely updated every 6 hours at 0000Z, 0600Z, 1200Z and 1800Z, and amended more frequently if weather conditions significantly change. Some major airports issue every two or three hours. We check for update every 10 minutes.

Displayed status time is time of most recent data update

PIREPs are updated when reported and follow no particular schedule. PIREPs older than about two hours are ignored. We check for new PIREPs every 5 mintues.

Displayed status time is time of most recent data update

Winds aloft are updated every 6 hours after the forecast model has executed: shortly after 0000Z, 0600Z, 1200Z, and 1800Z. (One of these four times will be displayed These reports are never amended, are "valid" for only a specific time in the future, but are "for use" during an interval.

Displayed status time is one of the four issueing times.

Airmets have largely been replaced by GAirmets, so this option shows Alaska Airmets and CONUS Sigmets. Airmets are issued every six hours for wide-spread weather impact, amended as needed. Sigmets issued every four hours and as needed. Alaska Airmets every 8 hours.

We check every ten minutes and display the time most recently checked.

"Graphical" Airmets are issued every three hours and amended as needed. They show changes over the next twelve hours. The displayed slider on the map lets you select which forecast time to view.

We provide an option to show "High" GAirmets which have a lower elevation of at least FL180

We check every ten minutes and display the time most recently checked.

NEXRAD precipitation radar is an animation which cycles through the previous 45 minutes, each frame representing 5 minutes. It pauses slightly at the most current reading.

While the data is "current", recognize that there are processing delays such that "current" is likely 15 minutes or more late.

Fronts represent surface analysis. Issued every three hours, about two hours after analysis of current observations. For example, 00Z analysis is issued at 0115Z and posted at 0145Z.

We check for updates every fifteen minutes. The status time displayed is the time of the most recent analysis and therefore will likely be a few hours in the recent past.

Airports are derived from NFDC data which is updated every 28 days.

We provide an option to display private airports. While most of these are very small, some are military airports. Always showing all airports can make some displays quite crowded.

TFRs are issued as needed. We check for updates every five minutes.

We obtain (most) information near the specified location or within a specified distance to your provided flight path. This reduces the data burden on our servers, your network and your browser.

We attempt to draw a grey border around the contained area, to give you a better idea of the data extent. (It is possible to construct flight paths which result in a poorly drawn border: the data should be accurate, our border-drawing routine is lacking.)