The Pilot Report, the UUA That Means Somebody Is Already in Trouble Up There, and Why You Are the Only Weather Sensor at Seven Thousand Five Hundred Feet

A PIREP (pilot report) is the only weather product in your briefing that comes from a pilot flying inside the weather in real time, rather than from a satellite, model, or ground station. It tells you what the sky actually did to another airplane at a specific altitude and location - information no METAR or TAF can give you. Learning to read a PIREP and, just as importantly, file one, makes you a safer pilot and a better decision-maker in the cockpit.

What Is a PIREP and Why Does It Matter?

Every other piece of weather you look at is a machine observing the sky from the outside. The METAR is an automated station or human observer on the ground looking up. The TAF is a forecaster’s educated guess. Winds aloft, prog charts, and graphical forecasts are all modeled or observed from somewhere other than where you’ll actually be flying.

But the air at 7,500 feet, twenty miles from your field, on a Tuesday afternoon? Nothing is measuring that. There is no weather station at your exact altitude in your exact patch of sky. The only sensor that exists up there is an airplane with a person in it.

That’s the entire value of the PIREP. It is the only aviation weather report generated from inside the weather, at altitude, in real time. The forecast tells you what someone thinks the sky will do. The PIREP tells you what the sky just did to another airplane - and on days the two disagree, the PIREP is usually the one telling the truth.

How Do I Read a PIREP?

A PIREP looks like alphabet soup the first time you see it, but the fields always appear in the same order. A typical report starts like this: UA /OV KMKE090015, followed by more coded fields. Read them in this sequence and the code starts to talk back to you.

UA vs. UUA: The First Thing to Read

The report begins with either UA or UUA, and this is the single most important field - yet most pilots skip right past it.

• UA means a routine pilot report. Someone saw something worth mentioning: light chop, a cloud layer, a smooth ride, the tops of a broken deck.
• UUA means an urgent pilot report. “Urgent” is a defined term, not drama. A UUA is filed for severe or extreme turbulence, severe icing, hail, a funnel cloud/tornado/waterspout, low-level wind shear, volcanic ash, or a sudden unforecast drop in visibility or ceiling.

When you’re scanning a briefing and your eye catches a double-U (UUA), stop and read that one first. Somebody up there keyed the mic while dealing with something that could hurt you. That report cost them something - pay attention.

The Core Fields, In Order

After UA/UUA, the coded fields follow a fixed order:

• OV (over) - Location, given as a bearing and distance from a VOR or airport. OV KMKE 090 015 means the report was made on the 090 radial, 15 nautical miles from Milwaukee - due east, 15 miles. Timing and geography matter: a turbulence report 15 miles east on a day the wind is howling from the west may be old news, or it may be about to roll over your field.
• TM (time) - The time in Zulu, four digits. A PIREP is a snapshot, and snapshots age. A smooth-ride report from three hours ago on a heating summer afternoon tells you almost nothing. A moderate turbulence report from eight minutes ago is gold. Always check the time before you trust a PIREP.
• FL (flight level) - Altitude in hundreds of feet. FL070 means 7,000 feet. This is what makes PIREPs so useful, because turbulence, icing, and cloud layers all live at specific altitudes. Moderate ice at 6,000 and a smooth, clear ride at 9,000 isn’t a contradiction - it’s a map showing you where the bad air is and where the good air is.
• TP (type of aircraft) - Quietly critical, and often overlooked. Turbulence is relative to the airplane feeling it. Moderate turbulence in a Boeing 737 is a very different afternoon in your Cessna 172. When you see TP C172, that report came from an airplane like yours - weight it heavily. When it came from a heavy jet, mentally turn the volume up, because you’ll feel more than they did.

The Remaining Fields

The rest fill in as needed:

• SK (sky cover) - Cloud layers, and crucially, tops and bases. A PIREP is often the only source for the actual tops of a layer. A TAF may give you a broken layer at 4,000 but won’t tell you the tops are at 6,500 with severe-clear above. A pilot will - and that single number can turn an ugly hard-IFR flight into a quick climb into sunshine.
• WX - Weather and flight visibility.
• TA - Temperature in Celsius.
• WV - Wind.
• TB (turbulence) and IC (icing) - The two that actually hurt people.

How Do I Interpret Turbulence and Icing Reports?

Turbulence in a PIREP carries an intensity word defined in the Aeronautical Information Manual (AIM) - these are precise, not casual:

• Light - Slight strain against the belt; the airplane bumps a little.
• Moderate - Definite strain against the belt; unsecured objects move, but you remain in control.
• Severe - Large, abrupt changes in altitude and attitude; the airplane may be momentarily out of control; you’re thrown against the harness.
• Extreme - The airplane is violently tossed and may be structurally damaged. This is filed as a UUA and reroutes airliners.

Here’s the honest part: even experienced pilots disagree on the line between moderate and severe. When you’re new, the safe move is to treat any turbulence report one category worse than it says, because you’re lighter and less experienced than whoever filed it.

Icing (IC) also carries an intensity - trace, light, moderate, severe - plus a type:

• Rime - Rough, milky ice that forms fast in cold visible moisture.
• Clear - Smooth, heavy glaze that runs back over the wing and is much harder to shed.
• Mixed - Both.

For those of us flying airplanes with no de-ice equipment - which is most of us - any icing PIREP in the clouds you planned to fly through is a stop sign, not a suggestion. Ice changes the shape of your wing and adds weight faster than you’d believe. A moderate icing report at your planned cruise altitude means you need a different altitude, a different route, or a different day.

How Do I File a PIREP?

Reading PIREPs is only half the job. The system only works if pilots actually report - and most don’t. We fly through a bumpy layer, grumble, climb, and never say a word, leaving the next pilot to get the same nasty surprise with no warning.

Filing is simple, and you don’t need to speak in code:

1. Get on the radio with Flight Service, or tell the controller you’re working with. (On the ground, you can use the phone or an app before departure.)
2. Key up and state your intent: “Flight Service, Cessna 12345, like to file a PIREP.”
3. Give the pieces in order: where you are, your altitude, your aircraft type, and what you’re seeing. The specialist codes it for you.

It sounds like this: “Level 7,500, Cessna 172, moderate turbulence, continuous.” That’s a complete PIREP - and you just made the sky safer for everyone behind you.

Should I Report a Smooth Ride Too?

Yes. A negative report is still a report. If the forecast screamed moderate turbulence all afternoon and you’re sailing along smooth as glass, tell somebody. A report that the ride is smooth and the tops are lower than forecast lets the pilot behind you relax, climb, and make a better decision. You might be the reason a nervous student launches on a beautiful day instead of scrubbing.

How Does a PIREP Change a Real Flight Decision?

Picture a 200-nautical-mile VFR cross-country on a fall afternoon. Your briefing looks decent: a broken layer forecast around 4,000 feet along the middle third of the route, winds from the west at 15, nothing scary. You’d fly that.

Then you scroll into the PIREPs and find a UA from 40 minutes ago - a Cessna 177, right along your route, at 6,500 feet, reporting the tops of that layer at 7,000 feet with moderate turbulence below the layer.

Look at what that one report did. It told you the layer is thicker than forecast, with tops well above your planned cruise. It told you the air underneath is rough, in an airplane a lot like yours. And it’s recent enough to trust. That’s not a scrub - it’s information. Now you can plan to top the layer at 8,500 feet in smooth air instead of bumping along underneath. One pilot, 40 minutes ahead of you, just handed you a better flight.

Why Do PIREPs Matter on a Checkride?

When the examiner walks you through a weather briefing on the oral, they want you to bring PIREPs into the conversation on your own - not just recite the METAR and TAF and stop. The examiner is listening for a pilot who says, “I checked the pilot reports along my route, and here’s what other airplanes are actually finding up there.”

That’s the difference between a student who memorized the products and a pilot who knows how to use them. The Airman Certification Standards (ACS) want to see you gather and interpret the weather. PIREPs are interpretation with a pulse.

Key Takeaways

• Read UA vs. UUA first. A UUA (urgent) signals severe/extreme turbulence, severe icing, hail, funnel clouds, wind shear, volcanic ash, or a sudden ceiling/visibility drop - read it before anything else.
• Always check the time (TM) and aircraft type (TP). An old report or one from a much larger airplane means something very different for your light single.
• Treat any turbulence report as one category worse than filed when you’re new, and treat any icing PIREP as a stop sign if you have no de-ice equipment.
• File PIREPs yourself - good rides and bad rides both matter. Call Flight Service and describe what you see in plain English.
• Once you leave the ground, you are the only weather sensor at your altitude. Act like it.