Prepavol's Weather page (“Weather” menu, /weather/) shows for an aerodrome the decoded METAR and TAF, the flight category, the active runways with the wind component, ephemeris data and weather charts. It requires permission to view the weather and the Weather module enabled for your club.
Searching for an airfield
When the page loads, it shows your club's airfield. To change it, type an ICAO code or a name in the “Aerodrome” field (for example LFPN or Toussus): suggestions appear from two characters. The “Nearest” button uses your browser's geolocation and shows the nearest aerodrome with its distance in nautical miles. If you refuse geolocation, the button cannot work.
Some small uncontrolled airfields do not broadcast a METAR. Prepavol then says so, and may offer the nearest station with its distance. In that case, also check the regional weather.
Where the data comes from and when it is updated
METARs and TAFs are retrieved from SkyHosting's aeronautical data service, then decoded by Prepavol. When this service does not answer, Prepavol can fall back on Aeroweb (Météo-France) if the account is configured, then on the last stored observation less than two hours old.
- The page does not refresh by itself: run the search again or reload the page to get the latest observation.
- The screen shows “Issued X min ago” and an estimate of the next METAR. This estimate is indicative: it assumes an issue on the hour or half hour.
- If the observation is more than one hour old, a banner asks you to confirm it before flight.
Reading the METAR
The “METAR” card shows:
- the AUTO, COR or SPECI badges when they apply (automatic observation, correction, special observation);
- the flight category, with the reason in brackets (ceiling or visibility) and a trend arrow;
- the raw message in a monospaced font;
- a decoded table: wind (with gusts or variable direction), visibility, RVR, phenomena, wind shear, temperature, dew point, temperature and dew point spread, QNH, clouds, observation time and trend (NOSIG, BECMG, TEMPO).
Clouds and phenomena are translated into plain language (for example “BKN, broken (5 to 7/8)” or “Rain”, with light, heavy or in the vicinity intensity). The ATIS button lets you listen to a reading of the observation. This reading is simulated and does not replace the official ATIS.
A bar shows the airfield's frequencies (ATIS, A/A, AFIS, INFO, five at most). A “NOTAM” badge flags a frequency changed by a NOTAM.
Flight categories
Prepavol assigns a category using the FAA-type rule, keeping the worse of ceiling and visibility. The ceiling is the base of the first BKN, OVC or obscured sky (VV) layer.
| Category | Ceiling | Visibility |
|---|---|---|
| VFR | above 3,000 ft | above 5 SM |
| MVFR | 1,000 to 3,000 ft | 3 to 5 SM |
| IFR | 500 to less than 1,000 ft | 1 to less than 3 SM |
| LIFR | below 500 ft | below 1 SM |
One statute mile (SM) is 1,609 metres.
Warning banners
Depending on the conditions, a banner appears at the top of the page:
- “VFR flight not possible” (red) in IFR or LIFR;
- “Marginal conditions (MVFR)” in MVFR;
- “Forecast weather degradation” when conditions are VFR but the TAF forecasts IFR or LIFR.
The banner also says whether a published instrument approach exists at the airfield (accessible with an IR rating) or not, and recalls the reference VFR minima: visibility of at least 5 km and ceiling of at least 1,500 ft. These are generic reference values, not the airfield's own minima.
For mainland France, a Météo-France vigilance banner appears from the yellow level, with the département, the colour, the phenomena and the source.
The TAF
The “TAF (Forecast)” card details the validity period, the changes (“From”, “Becoming from”, “Temporarily from”) and the probabilities. The long TAF, short TAF and PREDEC variants only appear if the source provides them.
Active runways, calculations and ephemeris
- The “Active runways” card lists for each runway the heading, the wind component and a calculated status: “Favourable”, “Crosswind” above 5 kt, “Strong crosswind” above 10 kt, “Tailwind” if the headwind component is negative. A NOTAM badge leads to the runway's NOTAMs, and the “Runway condition (RCR)” block appears if one exists, marked “Expired” after 8 hours.
- The “Calculations” card gives the elevation, the pressure altitude, the ISA temperature and the deviation from ISA.
- The “Ephemeris” gives the start and end of the aeronautical day (sunrise minus 30 minutes, sunset plus 30 minutes), sunrise, sunset and the length of the aeronautical day.
Weather charts
The “Fronts”, “TEMSI” and “WINTEM” tabs show the charts with an animation player. They depend on an Aeroweb account configured by Prepavol: if the slot list is empty, the source is not available at the moment.
The “Visibility & ceiling (AROME)” page shows two maps of France estimated from Météo-France's AROME model, with a lead time slider from +1 h up to +51 h. These are fields derived from a model: this is not an official document like the TEMSI, METAR or TAF.
Frequently asked questions
Why does my airfield have no METAR?
Small uncontrolled airfields generally do not broadcast a METAR. Prepavol says so and may offer the nearest station. Also check the regional weather (TEMSI, WINTEM) for your preparation.
Does the page update automatically?
No. Run the search again or reload the page to get the latest observation. A banner warns you if the observation is more than one hour old.
Does the VFR category shown mean I can fly?
No. It is a reading aid based on ceiling and visibility. You remain responsible for checking the regulatory minima applicable to your flight, with the official sources.
Where does the vigilance shown come from?
It comes from Météo-France and appears from the yellow level, for mainland France only.