DOCS / MISSION GENERATOR / WEATHER AND METAR

Weather and METAR

Weather complexity is computed from real METAR data — never procedurally generated. The same TAF and METAR your VATSIM controllers see feeds the multiplier on your mission. Marginal weather pays more; CAVOK pays the base rate.

~3 MIN READ

Sources

  • Primary: VATSIM METAR endpoint, queried alongside the data feed. This is what controllers use; the multiplier therefore matches the network's reality.
  • Fallback: aviationweather.gov for airports VATSIM doesn't surface. Same NOAA-sourced data.

Both sources are read on-demand at generation time and at landing time. Nothing is persisted in our database beyond the per-mission snapshot of "what was the METAR when this completed?".

What we read

We parse five fields out of each METAR:

  • Ceiling — lowest broken or overcast layer in feet AGL.
  • Visibility — prevailing visibility in statute miles or kilometres.
  • Wind — sustained speed in knots.
  • Gusts — peak gust speed if reported.
  • Significant weather — thunderstorms (TS), freezing precipitation (FZRA), snow showers (SHSN). Flagged but not currently a separate multiplier.

We do not read or store the raw METAR string in the database — only the parsed fields needed for scoring. The full string is rendered to you on the mission card via a fresh fetch.

Difficulty scoring

Each factor that crosses a threshold adds to the weather multiplier. Multiple factors stack additively up to a 1.3× cap. CAVOK (clear sky, >10km visibility, light wind) gives the base 1.0×.

FACTORTHRESHOLDEFFECT
Ceiling (cloud base) <1,000ft +0.15× base
Ceiling (marginal) 1,000–3,000ft +0.05× base
Visibility <3 SM / 5 km +0.10× base
Wind (sustained) >25kt +0.05× base
Gust factor Gusts >35kt +0.05× base

The multiplier is computed for both dep and arr; the higher of the two is what applies (you took the harder of the pair, you get paid for it).

Diversion threshold

Weather can force a diversion. The completion verifier accepts a diversion as a successful — not failed — outcome when all three are true:

  1. The METAR at the filed arrival, at the time of arrival, is below applicable mins (or the airport reported VRB visibility <1 SM, or ceiling at OVC for an IFR-only field).
  2. You landed within 75nm of the filed arrival.
  3. Your VATSIM flight plan was active at the time of the alternate landing.

The diverted outcome pays a partial reward (typically 60–70% of the base) and does not trigger the crash penalty. Your XP earns the same pro-rated share.

Freshness

METAR updates roughly every 30–60 minutes per airport. vCareer's generator uses whatever the most recent METAR is — we don't extrapolate, we don't blend, we don't smooth. If a METAR is older than 90 minutes we treat it as missing and fall back to "weather complexity = 1.0×" for that airport (it's not your fault the reporting station is silent).

NOTE
We never generate synthetic weather. Marginal conditions on the board reflect real marginal conditions in the real world right now. If you're seeing a string of high-weather-bonus missions, the weather is genuinely awful somewhere.