PIREP Guide: How to Read and File a Pilot Report

A PIREP is the only weather product in aviation written by somebody who was actually there. Everything else is measured by a machine or produced by a model.

That makes this PIREP guide worth more than its length suggests. A single report from an aircraft at your level, twenty minutes ago, beats six hours of area forecast.

The fields, in order

A PIREP is built from tagged fields, each opened by a slash and a two-letter code. Not every report carries every field.

Before those fields comes the station and the report type. UA is routine and UUA is urgent.

A worked example

Take KDFW UA /OV DFW360015 /TM 1930 /FL085 /TP C172 /SK BKN050-TOP070 /TB LGT /IC NEG /RM SMOOTH BELOW.

Read it field by field. The report is filed against Dallas Fort Worth, and it is routine. The position is 15 miles on the 360 radial from DFW.

The time is 1930 Zulu. The aircraft was at 8500 feet, and it is a Cessna 172.

The sky field says broken cloud with a base at 5000 and tops at 7000. Turbulence was light. There was no ice at all. And the remark adds that it was smooth lower down.

That last part is why remarks matter. Nothing in the coded fields could tell you where the smooth air was.

Reading turbulence and icing

The two hazard fields carry most of the value, and both work the same way.

Each takes an intensity: trace, light, moderate, severe or extreme. Each can take a frequency in front, such as occasional or continuous. Each can take a type after, such as chop or clear-air turbulence for /TB, or rime, clear or mixed for /IC.

Altitudes often follow. /IC MOD RIME 060-080 means moderate rime ice between 6000 and 8000 feet, and that band is the most useful part of the report because it tells you how far to climb or descend to leave it.

Read the aircraft type alongside the intensity, every time. Moderate turbulence in a light single is not moderate turbulence in a jet.

Why negative reports matter

NEG and SMOOTH look like empty reports. They are among the most useful ones in the system.

Icing and turbulence forecasts are broad and cautious by design. They have to be, because they cover thousands of square miles for six hours at a time.

A pilot who flew through the forecast band and met nothing has given you information the forecast cannot contain. A run of negative reports through a level is real evidence that the level is currently clean.

So file them. A report of nothing is not a wasted call.

Filing your own

There is no need to know the format. Say what you have and let the specialist code it.

Four things make a report useful: where you were, how high, what you were flying, and what you met. Position and altitude without an aircraft type is much weaker, because the type sets the scale for every intensity word.

Pass it to the controller you are working, or to flight service. If you are somewhere quiet with nobody to talk to, file it after landing. A late report is still worth more than none.

Report the good as well as the bad. Cloud tops are especially prized, because they tell everybody behind you whether climbing on top is available.

What to check before trusting one

Three fields decide how much a report is worth to you.

Time first. Conditions move, so an hour-old turbulence report is history. Cloud tops age better than hazards do.

Position next. Icing and turbulence tie to terrain and to fronts, so a report forty miles upwind may matter more than one twenty miles across your track.

Type last, and never skip it. It is the scale the hazard words were measured against.

Where PIREPs come from

Not every report in the feed was spoken by a pilot, and the header tells you which kind you have.

UA and UUA mark a true pilot report. Somebody talked, and somebody typed it up. These carry remarks and judgement.

ARP marks an AIREP, downlinked by the aircraft with no human involved. The fields sit in fixed positions with no slashes, and the hazard words are the same.

Automated reports are frequent and even. Voice reports are rarer and richer. Both land in the same feed, so glance at the header before you weigh one.

There is one catch worth holding. An AIREP has no urgent form, so severe conditions in an automated report get no special handling.

Verdict on this PIREP guide

Read a PIREP in three passes. Where and when, from /OV and /TM. What was met, from /TB, /IC and /SK. Then who met it, from /TP, which tells you how much the intensity words mean for your aircraft.

And file your own, including the quiet ones. The system only works because pilots keep feeding it, and the report costs you one radio call.

Last updated August 29, 2026