Reading a METAR in 60 Seconds
A METAR looks like an alphabet-soup rebus. It is actually a fixed-order weather report you can read in under a minute once you know the sequence.
A METAR intimidates the way a chess notation intimidates: dense because it is precise, not because it is complicated. Every field appears in a fixed order. Once you know the order, you can decode the report at a glance.
Take: METAR KOSH 011555Z 23012G18KT 10SM SCT045 BKN060 28/19 A2992. Field by field: KOSH — Wittman Regional at Oshkosh, Wisconsin. 011555Z — reported at 15:55 UTC on the first day of the month. 23012G18KT — wind from 230° at 12 knots, gusting 18. 10SM — visibility 10 statute miles. SCT045 — a scattered cloud layer at 4500 ft AGL. BKN060 — a broken layer at 6000 ft, which by definition sets the ceiling. 28/19 — temperature 28 °C, dew point 19 °C, giving a spread wide enough to keep fog off the runway. A2992 — altimeter setting 29.92 inches of mercury.
Weather phenomena, if present, appear between visibility and clouds using coded modifiers: −RA for light rain, +SN for heavy snow, BR for mist, FG for fog, TSRA for a thunderstorm with rain. Remarks after RMK carry additional detail — SLP (sea-level pressure), PRESRR (pressure rising rapidly), tornado reports, and so on. A pilot who can read the fixed-order body can safely ignore most of the remarks section for a routine go/no-go decision.
The value of reading METARs directly is that you form a mental picture of the weather instead of trusting an app to have formed one for you. Ceiling, visibility, wind, and pressure — in that order, that fast — is the entire preflight weather check when the departure and destination are close together and the sky is unremarkable.