The METAR Remarks Section, the Coded Notes After RMK, and the Sea-Level Pressure, Peak Wind, and Pressure Tendency Most Pilots Fly Right Past

The METAR remarks section, everything after the letters RMK, contains decoded weather intelligence most pilots skip entirely: sea-level pressure (SLP), peak wind (PK WND), precipitation totals, and pressure tendency. These groups can change a go/no-go decision because they reveal wind gusts, storm timing, and whether pressure is rising or falling - information the coded main body simply doesn’t carry. Learning roughly six or seven remark types will let you interpret a METAR better than many pilots who never scroll past the altimeter setting.

What Is the METAR Remarks Section?

A METAR is not a sentence - it’s a code, built to pack maximum information into the fewest characters back when observations went out over teletype and every character cost money. The Federal Aviation Administration and the National Weather Service standardized the format.

METAR stands for an aviation routine weather report. It is an observation, not a forecast - what is actually happening at the field right now or within the last hour.

Most pilots read the main body and stop: wind, visibility, ceiling, altimeter. But after those three letters, RMK, the observation starts telling you things the coded body cannot.

How Do You Decode a Full METAR Example?

Here’s a sample from KOKC (Oklahoma City) we can decode piece by piece:

• Day and time: the 1st of the month at 1955 Zulu
• Wind: from 220 degrees at 15 knots, gusting to 25
• Visibility: three-quarters of a statute mile
• Weather: thunderstorm, heavy rain, and mist
• Sky: overcast at 1,000 feet, cumulonimbus
• Temperature/dew point: 18°C over 16°C
• Altimeter: 29.92

Stop there and you have a clear picture: low ceiling, poor visibility, a thunderstorm on the field. That’s a no-go, and it isn’t close. But the remarks add detail that changes how you think about the whole system.

What Does SLP Mean in METAR Remarks?

The first remark you’ll often see is SLP followed by three numbers. In our example, SLP132.

That’s sea-level pressure, and it is not the same as the altimeter setting. The altimeter, 29.92, is what you dial into your Kollsman window. Sea-level pressure is the actual atmospheric pressure reduced to sea level, reported in shorthand: 132 means 1013.2 millibars (hectopascals).

Why care? One reading alone doesn’t tell you much. But sea-level pressure across many stations is how meteorologists track the real movement of pressure systems - whether a low is deepening and approaching, or filling and moving away. It’s the honest pulse of the atmosphere.

Why Does Peak Wind (PK WND) Matter So Much?

Peak wind is the remark that can genuinely save your airplane. In our example you might see PK WND 22030/1946.

That decodes to: the peak wind since the last routine observation was from 220 degrees at 30 knots, occurring at 46 minutes past the hour (1946 Zulu).

The body said the wind was gusting to 25 knots. The remarks just told you that nine minutes earlier, the field saw a gust to 30 knots. That five-knot difference can be the line between a crosswind you’re comfortable with and one right at the edge of what you and the airplane can handle.

Examiners look for exactly this. When they hand you a weather packet, they don’t want the gust factor read off the top line - they want you to find the peak wind in the remarks and factor it into your crosswind component. That’s the difference between reading weather and understanding it.

What Does the P Group (Precipitation) Tell You?

Near the end you’ll often see the letter P followed by four numbers. In our example, P0002.

That’s precipitation: two hundredths of an inch of liquid precipitation in the last hour. On a dry day it won’t appear at all. On a day like this, it confirms the rain is real and accumulating - which means standing water on the runway and a storm that’s producing, not just threatening.

How Do You Read the Pressure Tendency Group?

On the top-of-the-hour and bottom-of-the-hour observations, you may see a five-digit group starting with the number 5 - for example, 51132.

Here’s how it breaks down:

• The leading 5 simply flags it as a pressure tendency group.
• The next digit (1 here) is the character - how the pressure behaved over the last three hours.
• The final three digits give the amount of change in tenths of a millibar.

The character digit is a code from 0 to 8. This is the part that matters:

• Codes 0, 1, 2, and 3 all mean pressure is now higher than three hours ago.
• Codes 5, 6, 7, and 8 all mean it’s now lower.
• The middle digit describes the shape: rising steadily, rising then falling, falling then rising, or falling steadily.

Why should a VFR pilot care about the shape of a pressure curve? Because falling pressure means weather is coming. Steadily and rapidly falling pressure ahead of you is one of the oldest, most reliable warnings in aviation - a system is approaching, and the good weather out the window has an expiration date. Rising pressure behind a front usually means improvement and clearing, though often with gusty winds as the system pulls away.

Picture a two-hour cross-country. Your destination reads VFR right now - clear skies, good visibility. Tempting to launch. But the remarks show pressure falling, and falling fast, over the last three hours. That’s the field whispering that VFR now might be IFR by arrival. Now you look harder at the Terminal Aerodrome Forecast (TAF) and build a real picture instead of a snapshot.

What Do AO1 and AO2 Mean?

You’ll see the letter A followed by O2: AO2. That means an automated station with a precipitation discriminator - a machine that can tell rain from snow. AO1 is a station without that ability.

The reminder here is that many observations have no human watching the sky. The machine reports what its sensors see. It can miss a thunderstorm just off to the side of the field or a cloud layer a human would catch. When you see AO2, you’re reading a machine - weight it accordingly, and on a convective day, look outside more.

What Do the Timing and Location Remarks Tell You?

Some remarks begin with TS, thunderstorm information. TSB25 means the thunderstorm began at 25 minutes past the hour. There’s a whole family: rain began, rain ended, thunderstorm began, thunderstorm ended - each with a time attached. That timeline tells you whether the storm is building on the field or started an hour ago and may be moving off.

Others tell you where the weather is. CB (cumulonimbus) followed by a direction - for example, cumulonimbus to the west, moving east - tells you not just that there’s a storm, but which way it’s headed. On a summer afternoon in convective season, that’s the whole ballgame.

The Four Questions to Ask at RMK

Next time you brief a flight, make one change: when you reach RMK, slow down and read every group. Ask yourself four questions.

1. Is the pressure rising or falling? Find the tendency group and let it tell you the atmosphere’s direction.
2. What was the peak wind? Not the top-line gust - the peak. Is it worse than the body suggested?
3. Is precipitation accumulating, and did it start recently? The P group and timing remarks show whether things are worsening or improving.
4. Am I reading a human or a machine? AO1 versus AO2 - on a convective day, trust a machine less and look outside more.

The remarks section is not bottomless. It’s a short list: sea-level pressure, peak wind, precipitation, pressure tendency, station type, and a handful of timing notes. Learn those six or seven things and you’ll read a METAR better than many pilots with twenty years who never scrolled past the altimeter.

The Airman Certification Standards, under weather information, ask you to obtain and interpret weather products - not just read or recite. Telling an examiner “the pressure at my destination has been falling steadily, which supports the approaching system in the TAF, so I’m treating this as likely deterioration” is interpretation. That’s the pilot they’re hoping walks into the room.

The decoding standards here come straight from the FAA’s Aviation Weather Handbook and the National Weather Service’s METAR documentation. For the full remarks list in one place, the Aviation Weather Center at the National Weather Service publishes it free.

Key Takeaways

• The METAR remarks (after RMK) carry decision-changing data the coded body can’t: sea-level pressure, peak wind, precipitation, and pressure tendency.
• Peak wind (PK WND) can exceed the top-line gust - in our example, 30 knots in the remarks versus 25 in the body - so factor it into your crosswind component.
• SLP is not the altimeter setting; SLP132 means 1013.2 millibars, and it’s how systems are tracked across stations.
• Pressure tendency codes 0–3 mean rising, 5–8 mean falling; steadily falling pressure warns of approaching weather.
• AO2 stations have a precipitation discriminator, AO1 do not - remember you may be reading a machine that can miss nearby weather.