METAR quick read
A METAR reads in a fixed order: station, time, wind, visibility, weather, sky, temperature and dew point, altimeter. Read it in that order every time and the code stops looking random.
The worked example
KJFK 121851Z AUTO 18012G22KT 10SM FEW045 SCT250 24/13 A2992
| Group | Reading |
|---|---|
| KJFK 121851Z | Station JFK, day 12, 18:51 UTC |
| 18012G22KT | Wind from 180 degrees at 12 knots, gusts 22 |
| 10SM | Visibility 10 statute miles |
| FEW045 SCT250 | Few clouds at 4,500 feet, scattered at 25,000 feet, neither is a ceiling |
| 24/13 | Temperature 24 C, dew point 13 C, spread 11, dry air |
| A2992 | Altimeter 29.92 inches of mercury |
The five traps
- Cloud heights are hundreds of feet AGL. BKN008 is a ceiling at 800 feet, not 8,000.
- Only BKN, OVC, and vertical visibility make a ceiling. FEW and SCT never do.
- BR is mist and FG is fog. The cut is 5/8 of a mile of visibility.
- A plus or minus in front of weather is intensity: +TSRA is a heavy thunderstorm with rain.
- Temperature and dew point within about 2 degrees means fog or low cloud is likely.
The 500 foot math
Your ceiling on any day is the lower of two numbers: 400 feet AGL from the rule, or the cloud base minus 500 feet. A broken layer at 800 feet leaves you 300 feet of legal sky. Run that subtraction before you launch, not after the warning.
FAQ
What is a SPECI?
An off schedule METAR issued when conditions cross a threshold between routine reports. Same code, fresher facts. A new SPECI beats your morning plan.
Do TAFs use the same code?
Yes, plus change groups. FM is an abrupt change, BECMG a gradual one, TEMPO a short dip, PROB a stated chance.