TAF Flight Planning Trainer
Bentonville West Wolverines UAS Program
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New here? A TAF (Terminal Aerodrome Forecast) is the coded weather forecast pilots read to plan a flight hours in advance. This page teaches you to read one, and to turn it into a flight-window decision you can defend out loud.
Work straight down the page, or jump to a piece once it ships: what the fields mean change groups flight window planner test yourself
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What to practice next
PracticePlan the Window
A METAR tells you what the sky is doing right now. A TAF — Terminal Aerodrome Forecast — tells you what a forecaster expects it to do for the next 24 to 30 hours, so you can plan a flight before you ever drive to the field.
How is this different from a METAR? A METAR is an observation — what a sensor measured a few minutes ago. A TAF is a forecast — what a person expects, hours from now. Neither replaces the other: check the TAF to plan your day, then check the METAR right before you fly to see what actually happened.
One thing to get straight now. “TAF says VFR at 1800Z” does not mean conditions will be VFR at 1800Z — it means the forecaster expects them to be. Read every group on this page as a prediction, not a promise, and confirm it against the actual METAR and your own eyes before you fly.
Example TAF — issued for KXNA:
Already comfortable reading a METAR? This page assumes you are — the METAR Tutorial covers wind, visibility, sky and weather codes in depth and is worth a refresher if any of this looks unfamiliar.
Today’s Forecast
Live KXNA forecast, paired with the current KVBT observation so the two ideas stay separate: a forecast for one airport, and conditions at another. Make a call for the next few hours, then check yourself once the forecast is on screen.
Loading current forecast…
Anatomy of a TAF
Every TAF opens the same way: report type, station, issue time, valid period, then an initial forecast that holds until the first change group. Click any piece below — or tab to it and press Enter — to see what it means. This section covers only the header and the initial forecast; the change groups that follow it get their own section next.
👆 Click any colored piece above
Each field explains itself here — what it says, and how it differs from the equivalent METAR field where one exists.
Change Groups
The single most-tested, most-missed concept on this page. A TAF's valid period isn't one flat forecast — it's a timeline, and four kinds of change group carry four different confidence levels. Collapsing them into “the weather changes” is exactly the mistake this section exists to prevent.
FM
A new prevailing forecast starts exactly at this time, replacing everything before it — instantly, not gradually. Format: FMDDHHmm, its own complete time, to the minute.
BECMG
Conditions shift smoothly across a whole window. Not fully in effect until the window ends — during it, treat the forecast as transitioning, not as one side or the other. Format: BECMG DDHH/DDHH.
TEMPO
Conditions may swing to this during the window, but the prevailing forecast still holds most of the time. An overlay, not a replacement — the forecast underneath it never stops applying.
PROB30 / PROB40
A 30% or 40% chance these conditions occur — never a prevailing forecast, never “probably going to happen.” Can combine with TEMPO for a probable temporary fluctuation.
Click anywhere along the timeline below — or on an overlay bar — to see which group applies at that point, and what it's forecasting.
👆 Click the timeline above
The forecast at that point in time will explain itself here.
Time Window Drill
A fresh, randomly generated TAF every round — no bank to memorize. Read it, find the target time, and answer two questions: which prevailing forecast applies there, and what it means for cloud clearance. TEMPO/PROB overlays never count as the prevailing answer — that's the whole point of doctrine rule 3.
Target time: —
Which forecast group is prevailing at this time?
If that layer sits over your operating site, what's the conservative under-cloud planning limit — in ft AGL?
Streak: 0 · Best: 0
Guided Walkthrough
Three TAFs, and the help drops away as you go. The first plays itself. By the last one you get the raw code, no color, and no narration — which is what reading a real forecast looks like.
TAF Decoder
Paste any TAF and get a plain-English breakdown of every forecast group, plus a timeline showing which group applies when — or look one up live for any station. This decoder handles the US TAF format — change groups FM, BECMG, TEMPO, PROB30/PROB40 (including PROB30 TEMPO), and NSW.
Check a specific time
Enter a Zulu time as DDHHmm (day, hour, minute) to see what this forecast says for that moment — this is what groupAtTime() computes, the same function the Time Window Drill (Phase 5) will use.
Look up any station's current TAF. Most small fields (like KVBT) don't have one — try a larger airport.
TAFs are typically issued every six hours, around 00Z, 06Z, 12Z, and 18Z, with amendments in between when conditions change enough to need one.
Flight Window Planner
Read each TAF and commit to a call before you look. Each scenario carries a real-world mission plus the aircraft profile and classroom SOP you're flying under. Some give you a target time; others ask you to find the best window yourself. Then: would forecast conditions meet the Part 107 minimums if this verifies, would you plan to fly, how sure are you, which condition is doing the limiting, what controls the decision, and what's the best response.
Exam Mode
Ten questions, no color coding and no hints. Several are built fresh from a randomly generated TAF every time you run it, so the exam can't be memorized — the only way through is to read the forecast. At the end you get a breakdown by topic, so you can see whether it's change groups, cloud clearance, or reading the valid period that keeps catching you.
You'll see raw TAFs with the colors switched off. Answer honestly and don't scroll up — a wrong answer here is worth more than a right one you looked up.
Choose a mode:
Practice shows feedback after each question. Checkride withholds feedback until all 10 are answered — like the real test. Run it again: the generated questions will be different ones, and this session remembers which topics you're weak on so later runs lean toward them.
Cheat Sheet
Print this page (Ctrl/Cmd+P) and only this section comes out — color coding intact — as a study card for your kneeboard. It includes the codes shared with the METAR tutorial too, so you don't need both printouts at a test.
TAF Field Order
| TAF / AMD / COR | Report type — original, amended, or corrected forecast |
| KXNA | Station ID |
| 101130Z | Issue time (Zulu) — DDHHmm |
| 1012/1112 | Valid period — DDHH/DDHH, day + hour only |
| 15006KT | Forecast wind dir/speed/gust |
| P6SM | Forecast visibility |
| -RA BR | Forecast weather phenomena |
| SCT250 | Forecast sky condition |
| FM102000 | Change group header (one of five kinds — see below) |
Change Group Reference
| FMddhhmm | From — clean break, new prevailing forecast starts instantly at this exact minute |
| BECMG hh/hh | Becoming — gradual transition; not fully in effect until the window ends |
| TEMPO hh/hh | Temporary — fluctuation layered on top; prevailing forecast still holds underneath |
| PROB30 / PROB40 hh/hh | Explicit probability (30% / 40%) of the stated conditions — never a claim of what will happen |
| PROB30 TEMPO | A probable, temporary fluctuation — combines both qualifiers |
| NSW | No Significant Weather — cancels a previously forecast phenomenon; not a claim of clear skies |
TEMPO/PROB30/PROB40 are overlays — never the prevailing forecast, no matter what time you ask about. Only INITIAL, FM, and a settled BECMG can be prevailing.
Common Weather Codes
Sky Coverage
| SKC | Sky Clear — no cloud forecast at all |
| VVnnn | Vertical Visibility — sky obscured, e.g. VV003 = vertical vis 300 ft AGL |
| CB | Cumulonimbus — appended to a layer, e.g. BKN020CB |
A ceiling is the lowest forecast BKN or OVC layer. But cloud clearance applies to the lowest layer of any coverage — FEW and SCT count too.
Wind Codes
| 00000KT | Calm forecast wind — direction digits zeroed, not literally "from 000°" |
| VRB03KT | Variable direction forecast — wind <6 kt, direction shifts constantly |
| 21015G25KT | Gust forecast — sustained 15 kt gusting to 25 kt from 210° |
TAF wind is from true north, same encoding as a METAR — three digits direction, two or three digits speed in knots.
Visibility Codes
| P6SM | Forecaster expects greater than 6 statute miles (P = plus) |
| 2SM | Forecast visibility of 2 statute miles |
| 1 1/2SM | One and a half statute miles (space separates whole and fraction) |
Statute miles, same as a METAR — there is no separate, lower TAF minimum.
Time Format Guide
| 101130Z | Issue time — DDHHmm, day + hour + minute |
| 1012/1112 | Valid period — DDHH/DDHH, day + hour, no minutes |
| FM102000 | FM always uses DDHHmm — a clean break can start at any minute |
| BECMG 1018/1020 | Change-group windows use DDHH/DDHH — hour only, no minute |
Mixing these two formats up is the single most common student error this page drills. All times are Zulu.
TAF vs. METAR
| METAR | What the weather is. An observation, taken at one field, usually hourly. |
| TAF | What the weather will be. A forecast for the airport named in the header, issued four times a day, covering 24 or 30 hours. |
§ 107.49 requires the remote PIC to assess local weather conditions; METARs and TAFs are important tools for doing so. A TAF alone won't tell you what the sky is doing right now — check the current METAR too.
Classroom Operating Limits
Three Different Questions
| 1. Forecast minimums | If this forecast group verifies, would it meet § 107.51? Would be MET or would NOT be met. |
| 2. Site verification | Flight visibility you can observe, where clouds actually are, 2,000 ft horizontal clearance, whether the layer is over your site, terrain, whether a newer TAF has replaced this one, what the current METAR shows. |
| 3. Operational call | Given the aircraft, the SOP, and the forecast's confidence level: GO, GO with restrictions, or NO-GO. |
"Would be MET" describes a prediction for an airport, conditional on it verifying — never a clearance at your site. Answer all three, in order.
Traps to Watch For
| A forecast, not a report | "TAF says VFR" means expected, not guaranteed. |
| NSW ≠ no weather | It cancels a prior phenomenon — sky and visibility can still be restricted. |
| SCT still counts | Cloud clearance applies to any forecast cloud, not just the ceiling. |
| PROB is never prevailing | Nor is TEMPO — both are overlays on the real prevailing forecast. |
| DDHHmm ≠ DDHH/DDHH | Issue time carries minutes; the valid period and change-group windows don't (except FM). |
| That airport is not your field | A TAF is a forecast for the station named — and for a different location than your site. |
| 2,000 ft is independent | No altitude satisfies the horizontal clearance obligation. |
Part 107 Weather Minimums
- Minimum flight visibility3 statute miles
- Vertical clearance from any cloud500 ft below
- Horizontal clearance from any cloud2,000 ft
- Maximum altitude (AGL)400 feet
- All TAF times are inUTC / Zulu
These apply to conditions at the time of flight — a forecast that wouldn't meet them isn't automatically illegal, it means plan and verify accordingly.