A flyability view of the next few days at EVAD, scored against one pilot's limits in a Rallye 180, VFR day. It answers "is it worth looking further", nothing more. It does not replace a brief, a TAF or a look at the sky.
Six constraints are evaluated and the worst one decides the hour and is shown as the binding letter. Wind direction from the models is degrees true; runway designators are magnetic, and the conversion happens before any component is computed — skipping it biases crosswind by up to about 1.6 kt at 10 kt, which is decisive against a 10 kt limit.
| Code | Constraint | Limit | Notes |
|---|---|---|---|
| X | Crosswind | 10 kt | Applies at every field; runway length never buys extra crosswind. |
| G | Gust | xw ≤ 10 kt and gust ≤ mean + 10 kt | Scored twice. Either failing is a no-go. |
| C | Ceiling | 2000 ft aimed at | Estimated, never observed at EVAD. Aimed at, not gated on. |
| V | Visibility | 10 km clean, 5 km floor | Between the two is a judgement call, not a no-go. |
| P | Precipitation | — | Rain rate, raised when CAPE indicates convection. |
| D | Daylight | On the ground 1 h before sunset | Night is not authorised. |
Model gust fields break down in light wind at any lead time. A gust factor above 2.2 on a light mean, or a gust below the mean, says the run has nothing to say about gusts. Those figures are shown but never allowed to close a day on their own — the hour is flagged for a TAF check instead.
Because they are less certain, and a grid that renders D+4 as confidently as D+1 is telling you something false. Measured at EVAD, forecast crosswind is good to the hour at D+1 and D+2, good to a half-day at D+3, and good only for the character of the day at D+4. The Accuracy page carries the current numbers.
The ceiling over EVAD, because nothing measures it. Whether the Adazi military training area is active, because NOTAM is behind a login — that check is mandatory and stays manual. And anything about a destination: this scores the home field only.
Model data from Open-Meteo (ECMWF IFS 0.25, ICON-EU, GFS), observations and TAF from aviationweather.gov, plus the unofficial on-field station at EVAD. Magnetic variation 9.19°E. Sunrise and sunset are computed, pending the AIP tables.