The Pilot Report, the PIREP, and Why the One Weather Product Written by Pilots Is the One Most Pilots Never File

A PIREP (pilot report) is the only weather product written by pilots rather than a computer or forecaster - a real-time observation of the actual conditions an aircraft is flying through, including cloud tops, bases, turbulence, icing, and visibility. Because it reports what is happening rather than what a model predicts, a single relevant PIREP can drive a go/no-go decision better than hours of chart study. Yet most pilots go years without ever filing one, leaving a chronic shortage of the exact data everyone wants on marginal days.

Why a PIREP Beats a Forecast

Almost every product in your briefing is a prediction. The Terminal Aerodrome Forecast (TAF) is a professional’s best guess. Winds aloft come from a computer model. Area forecasts, graphical forecasts, and prog charts are all educated forecasting - valuable, but still prediction.

Prediction has a blind spot: it cannot tell you what is actually happening right now at 4,500 feet over the ridge you’re about to cross. Only a pilot up there can tell you that.

That’s what a PIREP delivers - a real observation from a real airplane in real time. A report that reads “smooth on top at 6,500” isn’t a guess. Somebody is up there, and it’s smooth.

How Do I Read a PIREP?

In raw form, PIREPs look like alphabet soup. Decode them and they become the most honest weather you’ll get.

There are two types. A routine report is coded UA (“you-ay”). An urgent report is coded UUA (“you-you-ay”). The urgent code is reserved for the things that ruin your day: severe or extreme turbulence, severe icing, hail, and low-level wind shear. The system flags these as urgent so they jump the line.

The report is built from fields, each with a letter identifier. You don’t need to memorize all of them, but these are the ones that matter:

• OV (over) - Location, usually relative to a navaid or airport. Check this first: a PIREP is only useful if it’s near your route.
• TM (time) - Given in Zulu, four-digit format. Weather moves, so a turbulence report three hours old is a history lesson, not a briefing. Always check the timestamp before letting a PIREP change your plan.
• FL (flight level) - The altitude the pilot was flying. This is the field students skip, and it’s the whole ballgame. Reported tops at 7,000 feet when you can climb to 8,500 is a plan. Reported tops at 17,000 in a normally aspirated single is a hazard.
• TP (type) - Aircraft type. Turbulence is relative to the airplane. Moderate turbulence in a Boeing 737 and moderate turbulence in a Cessna 172 are not the same sky. If an airliner reports light chop, brace yourself - it may be far more than light for you.
• SK (sky condition) - Cloud bases and tops.
• TB (turbulence) and IC (icing) - The core hazards.
• RM (remarks) - Plain-language color commentary that doesn’t fit elsewhere.

What Does a Decoded PIREP Look Like?

Say your briefing shows this: UA / OV Boise / TM 2145Z / FL065 / TP C182 / SK tops 6,500 / TB light / IC negative / RM smooth and clear on top.

Here’s the story: about 45 minutes before your briefing, a pilot in a Cessna 182 - likely a lot like whatever you’re flying - was over Boise at 6,500 feet. Cloud tops were right at that altitude. Above them it was smooth, clear, and free of ice.

Now compare that to a TAF that just says the layer is broken at 4,000. The forecast tells you there are clouds. The PIREP tells you that if you can climb through them, there’s a smooth, sunlit highway on the other side.

PIREPs also warn you. Icing is the big one. Forecast icing is a probability - the meteorologist saying conditions could support ice. But a report reading UUA / moderate rime ice / 6,000 to 9,000 / accumulating fast is a pilot telling you it’s happening right now in the exact block of air you planned to fly. There’s no arguing with that report.

How Do I File a PIREP Without Fumbling the Radio Call?

The system has a hole in it, and the hole is us. On marginal days - when you most want data - you’ll often find only two reports for a whole region, both hours old. Forecasters, controllers, and Flight Service all beg for PIREPs because every product improves the moment a real pilot reports actual conditions. Most pilots don’t file because they’re busy, don’t want to clutter the frequency, or feel intimidated by the call.

You have three easy ways to file:

1. Tell whoever you’re already talking to. On flight following, key up: “Center, Cessna 821TM, PIREP when you’re ready.” They’ll say go ahead, and you talk in plain English. They translate it into the coded format - that’s the machine’s job, not yours.
2. Call Flight Service - in the air by radio, or on the ground before or after your flight. Plain language; the briefer does the coding.
3. Use your electronic flight bag. Most popular apps let you file with a few taps: position, altitude, conditions, send. With connectivity, it’s a 15-second job.

The format to keep in your head is a simple flow - where, when, what:

• Where am I: “Twenty miles south of Boise.”
• What altitude: “Six thousand five hundred.”
• What am I seeing: “Tops right at my altitude, smooth on top, no ice.”

The “when” is implied by the fact that you’re reporting it now. Add your aircraft type if you like, or the briefer will ask. The core is just those three things - and you’re already looking at them out the window.

How Does a PIREP Change a Real Cross-Country Decision?

Say the forecast is ugly in the middle: a broken-to-overcast layer, uncertain tops, and a chance of ice above the freezing level. On paper it’s a coin flip.

During your briefing, you go hunting for PIREPs along your route and find one from a pilot 40 minutes ahead, in your altitude range, reporting tops at 8,000, smooth, negative ice, clear above. That single report just turned a coin flip into a plan. You climb, break out, and fly exactly what that pilot described.

Now flip it. The PIREP you find reports tops at 16,000 and moderate ice from 9,000 to 14,000. That report just saved you from launching into a trap. You stay on the ground, route around it, or wait for the afternoon - a real decision based on real information, with a fellow pilot to thank.

Why Examiners Want to Hear About PIREPs

On your checkride, when you brief your cross-country, don’t just recite the TAF and winds aloft. Look for PIREPs and mention them: “I checked for pilot reports along my route, here’s what I found, and here’s how it confirms or changes my plan.”

That tells the examiner you understand the difference between a forecast and an observation - that you know the sky doesn’t always read the forecast. The Airman Certification Standards (ACS) require you to obtain and correctly analyze the weather, and PIREPs are part of that picture that many applicants forget exists.

The deeper thing being tested outlives the checkride: that you’ll keep seeking real information for the rest of your flying life, rather than trusting a forecast just because it was easy to pull up.

Key Takeaways

• A PIREP is the only weather product written by pilots - a real-time observation, not a prediction - making it uniquely trustworthy for go/no-go decisions.
• Routine reports are coded UA; urgent reports are UUA, reserved for severe turbulence, severe icing, hail, and low-level wind shear.
• Always check the OV (location) and TM (time) fields first - a PIREP is only useful if it’s near your route and recent; treat turbulence relative to the reporting aircraft’s TP (type).
• File in three ways: tell the controller you’re already talking to, call Flight Service, or tap it into your EFB app.
• The whole call is just where, altitude, what you see - the briefer handles the coding.