Weather Information

91.103 requires each PIC, before beginning a flight, to become familiar with all available information concerning that flight. For a flight under IFR or not in the vicinity of an airport, that includes weather reports and forecasts, fuel requirements, alternatives if the planned flight cannot be completed, and any known traffic delays. For any flight, it includes runway lengths at airports of intended use and takeoff and landing distance data.

AC 91-92 frames the standard usefully for teaching: preflight actions are "a rehearsal of the whole flight with contingencies added." Teach it that way — the student narrates the flight before flying it, and states what would make each phase not work.

K1 asks you to describe and explain the sources, not just name them. Teach who makes the weather versus who delivers it:

• NOAA — the parent scientific agency, part of the Department of Commerce, focused on the oceans, major waterways, and the atmosphere
• National Weather Service (NWS) — a part of NOAA, tasked with weather forecasts, warnings of hazardous weather, and other weather products for organizations and the public. The NWS is the origin of nearly everything your student reads
• Aviation Weather Center (AWC), aviationweather.gov — the NWS unit that packages it for aviation: GFA, AIRMETs, SIGMETs, Convective SIGMETs, FB, and the CVA
• NWS Storm Prediction Center (SPC), spc.noaa.gov — the Convective Outlook (AC)
• Alaska Aviation Weather Unit (AAWU), weather.gov/aawu — the Alaska equivalent
• Flight Service — the FAA's delivery and consultation service: pilot briefings, flight plans, in-flight advisory services, SAR initiation, and NOTAMs, before, during, and after flight. Its web portal, 1800wxbrief.com, gives online preflight briefings, flight plan filing, and automatic notifications and alerts for adverse weather, airport closures, NOTAMs, and TFRs
• FIS-B — automatically broadcast weather over 978 MHz UAT to equipped aircraft, national and regional

(AC 91-92 4.6–4.12, 7.4.1.2)

The distinction worth teaching: Flight Service is a conduit and a consultant, not a source. A student who thinks "the briefer's weather" is different from "the app's weather" doesn't understand that both are reading NWS products. What Flight Service adds is a human who can tell you what the products don't say.

Yes. AC 91-92 states the FAA "considers that a self-briefing may be compliant with current Federal aviation regulations," and encourages pilots to self-brief using online automated resources before contacting Flight Service, so Flight Service becomes a consultative resource used when needed.

Teach the student that "self-brief" does not mean "glance at an app." It means working the checklist below and being able to say what the weather is doing.

Assemble the flight details first — type of flight (IFR/VFR), aircraft ID and type, departure point, route, destination and alternates, altitudes, ETD and ETE. Then:

1. Adverse conditions — low-level wind shear, thunderstorms, reported icing, frontal zones along the route, NOTAMs (closures, delays, TFRs), and weather advisories: SIGMETs, AIRMETs, Convective SIGMETs, Center Weather Advisories, Aviation Watch Notification Messages
2. Synopsis — type, location, and movement of weather systems and air masses
3. Current conditions — METARs, PIREPs, satellite and radar; may be omitted if departure is beyond 2 hours
4. En route forecast — GFA, TAFs, prog charts, advisories, reviewed in logical order: climbout, en route, descent
5. Destination forecast — including significant changes expected within 1 hour before and after ETA; select an alternate if needed
6. Winds aloft — interpolate between levels and stations, noting large shifts as a means of identifying wind shifts
7. NOTAMs — domestic, international, special use airspace, and field conditions (FICON)

Adverse conditions come first on purpose. A student who reads the METAR first has already anchored on "it looks fine here."

A METAR is the routine surface observation for an airport; a SPECI is the same format issued off-schedule when conditions change significantly. A PIREP is an actual report of what a pilot encountered — AC 91-92 calls PIREPs "a valuable source of in-flight information regarding en route conditions including turbulence, icing, visibility, temperature, and winds aloft," notes the NWS uses them to validate and adjust forecasts and feeds them into numerical models, and stresses they should also be filed when favorable weather is found where adverse conditions were forecast.

The teaching point students miss: a METAR tells you what a machine measured on the ground; a PIREP is the only report of what the air is actually like where you will be flying. Build the habit early — have the student file one on every dual cross-country, from the airplane or by phone after landing.

A TAF is established for the 5-statute-mile radius around an airport, is valid for 24 or 30 hours, and is updated four times a day at 0000Z, 0600Z, 1200Z, and 1800Z (PHAK ch. 13). It uses the same descriptors and abbreviations as the METAR.

Change groups worth drilling:

• FM — a rapid and significant change, usually within an hour
• TEMPO — temporary fluctuations expected to last less than 1 hour
• PROB30 — a probability of thunderstorms and precipitation; not used for the first 6 hours of a 24-hour forecast

The limit to teach out loud: the TAF covers 5 miles around one airport. It says nothing about the ridge halfway there. Students routinely brief two TAFs and believe they have briefed the route.

• AIRMET (WA) — issued every 6 hours with intermediate updates as needed. Forecasts moderate icing, moderate turbulence, sustained surface winds of 30 knots or greater, widespread ceilings less than 1,000 ft and/or visibilities less than 3 miles, and extensive mountain obscurement. Sierra = IFR and mountain obscuration; Tango = turbulence, strong surface winds, low-level wind shear; Zulu = icing and freezing levels.
• SIGMET (WS) — unscheduled, valid 4 hours (6 hours for a hurricane). Non-convective hazards to all aircraft: severe icing not associated with thunderstorms, severe or extreme turbulence or CAT not associated with thunderstorms, dust or sandstorms lowering visibility below 3 miles, and volcanic ash. Identified November through Yankee; the first issuance is an Urgent Weather SIGMET (UWS).
• Convective SIGMET (WST) — valid 2 hours, issued at 55 minutes past the hour for the eastern, western, and central contiguous U.S. (not Alaska or Hawaii). Triggered by severe thunderstorms with surface winds greater than 50 knots, hail at the surface greater than or equal to ¾ inch in diameter, or tornadoes; also embedded thunderstorms, lines of thunderstorms, or thunderstorms with heavy or greater precipitation affecting 40 percent or more of a 3,000-square-mile or greater region. If nothing hazardous exists, it is still issued, reading "CONVECTIVE SIGMET…NONE."

No, and the correction is a teaching opportunity rather than a fact. An advisory is a forecast of conditions over an area, not a prohibition — and the forecast conditions are not guaranteed to exist along your particular route.

Then give them the framework that actually decides it:

• The advisory tells you a hazard is expected and where.
• A PIREP confirming the hazard turns "expected" into "reported."
• The aircraft's operating limitations and your personal minimums decide whether that hazard is one you may or should accept.

A trainer is not certificated for flight into known icing, so a Zulu AIRMET with confirming PIREPs at your altitude ends the discussion — not because the AIRMET forbids it, but because the airplane does.

• Surface Analysis Chart — the synopsis product: type, location, and movement of pressure systems, air masses, and fronts
• Ceiling and Visibility Chart (CVA) — the ACS wording in AI.III.C.K2b; a graphical current-conditions depiction of ceiling and visibility
• Graphical Forecasts for Aviation (GFA) — the primary en route forecast tool; AC 91-92 points to aviationweather.gov, noting the GFA "gives a comprehensive picture of weather that may impact a flight"
• Winds and Temperatures Aloft (FB) — forecast wind and temperature for specific locations, made twice a day from the 0000Z and 1200Z radiosonde observations. Winds are not forecast within 1,500 ft of station elevation and temperatures not within 2,500 ft, which is why the lowest reportable level differs by station (PHAK ch. 13 — Denver at 5,431 ft starts at 9,000 ft)
• Convective Outlook (AC) — the Storm Prediction Center's convective forecast, at spc.noaa.gov (AC 91-92 7.4.1.2)

The FB is the one to teach with a pencil. A student who can interpolate between two levels and two stations has a usable wind for the leg; one who reads the nearest number does not.

Teach one sentence and make them repeat it: the in-cockpit NEXRAD display depicts where the weather WAS, not where it IS (PHAK ch. 13).

The specifics that make it land:

• The radar image is not real time and can be up to 5 minutes old
• The age indicator shows the age of the mosaic image, not the age of the weather — actual conditions can be 15 to 20 minutes older than the age indicated
• The NTSB has reported two fatal accidents where in-cockpit NEXRAD mosaic imagery was available near quickly-developing, fast-moving convective weather; in one, the images were 6 to 8 minutes old
• At no time should the images be used as storm-penetrating radar or to navigate through a line of storms — reference only

The habit to build: a student who uses datalink to avoid a system by a wide margin is using it correctly; a student who uses it to thread a gap has misunderstood what the picture is.

Use the FAA Personal Minimums Checklist in AIH Appendix D, which reflects the PAVE structure. Its own instructions are the lesson:

• Give yourself permission to choose higher minimums than the regulations, flight manuals, or other rules — "Conservatism Without Guilt"
• Be wary of a marginal item in any single risk category; if you have marginal items in two or more categories, do not go
• Review and revise as proficiency, recency, and training change
• Never make minimums less restrictive unless a significant positive event has occurred, and never when planning a specific flight — "or else external pressures will influence you"

Fill in real blanks with the student: takeoffs and landings in the last N days, hours in make and model, VFR day and night fuel reserves, crosswind as a percent of POH maximum, runway length as a percent more than POH, and how old reports and forecasts may be. AIH 1 gives the worked example — the AFM allows a 15-knot crosswind component, the pilot has flown 10, so 10 knots is the personal limit until training changes it.

Use the 3P model — Perceive, Process, Perform — which AIH 1 maps directly onto the risk management process: perceiving identifies the risk, processing assesses it, performing implements the control. Perceive with PAVE: Pilot, Aircraft, enVironment, External pressures. Once a course of action is selected, the process begins again, because the circumstances have changed.

AIH 1 is explicit about the instructor's role: "It is never too early to start teaching risk management," and it recommends making the 3P discussion a standard feature of the preflight discussion, because "risk management habits are best developed through repetition and consistent adherence to specific procedures."

So make it a ritual, not a lecture. Every lesson, before the airplane: perceive, process, perform, out loud, by the student.

Divert when the conditions you planned for are no longer the conditions you have and the destination is no longer the best option — deteriorating ceilings or visibility ahead, a shifting or strengthening headwind eating the fuel plan, terrain or airspace forcing a lower altitude than briefed, an unforecast frontal passage, or convective weather building across the route.

The reason students don't divert is not that they can't identify it; it's that they never rehearsed it. Train it three ways:

1. Pick the alternates on the ground, by name, for every cross-country — and write the decision point on the nav log.
2. Set a hard trigger before departure. "If the ceiling at the halfway point is below 3,000, I turn." A number decided in the airplane is a negotiation; a number decided on the ground is a rule.
3. Fly the divert on a dual cross-country, at least once, all the way to a full stop at the alternate. AIH ch. 3's law of intensity: real-world scenarios make a vivid impression that a briefing cannot.

• Atmospheric stability (K3a). Stable air gives stratiform clouds, steady precipitation, smooth air, and poor visibility trapped under an inversion; unstable air gives cumuliform clouds, showery precipitation, good visibility, and turbulence. Implication for the lesson: stable means a smooth day for first landings but a haze layer that hides the horizon on the way to the practice area; unstable means good visibility but a student fighting the airplane in the pattern.
• Moisture and the temperature/dewpoint spread (K3d, K3j). As temperature and dewpoint converge the air nears saturation — expect fog, cloud, or precipitation. Implication: a solo student launched on a 2 °C spread at sunset may return to an airport that has gone IFR. This is the classic first-solo-cross-country trap.
• Turbulence (K3g). Convective, mechanical, wind shear, and wake. Implication: turbulence sets the ceiling on what you can teach. Slow flight and stalls in moderate turbulence teach the student that the airplane is unpredictable — a false lesson that primacy will make expensive to undo.

Name the implication for the lesson, not just for the flight. That is the instructor-level answer.

An air mass takes on the characteristics of the surface beneath it. Passing over a warmer surface it becomes unstable — convective currents, cumulus clouds, showers, turbulence, and good surface visibility. Passing over a colder surface it becomes stable — no convective currents, low stratus and fog, and poor surface visibility, because smoke, dust, and other particles can't rise out and stay trapped near the surface (PHAK ch. 12).

A front is the boundary layer between two air masses of different characteristics, and an approaching front of any type always means the weather is about to change. No two fronts are identical, but a warm front is the one worth drilling: warm air advances and replaces colder air, moving slowly, typically 10 to 25 mph, sliding up over the cool air, so expect cirriform then stratiform clouds and fog along the boundary — and in summer, cumulonimbus. The rest of the family — cold front, stationary front, and occluded front — is covered in PHAK ch. 12.

The instructor angle: a warm front is the one that ruins solo cross-countries, because it arrives slowly and looks fine — a gradual lowering of a stratiform deck, hours ahead of the front itself. Teach the student to brief the synopsis (the systems and their movement) before the METARs, so they see the front coming rather than reading a snapshot that still says VFR.

Clouds (K3f) are classified by the height of their bases (PHAK ch. 12):

Icing and freezing level (K3i). Water that stays liquid above the freezing level is supercooled, and it freezes on contact with the airframe — producing clear ice (glossy, clear, or translucent), rime ice (rough, milky, opaque), or mixed (PHAK glossary). Icing can occur at any altitude above the freezing level. For a VFR trainer the freezing level is a hard planning number, not trivia: it tells you which altitudes are unavailable if you end up in visible moisture, and it is exactly what the Zulu AIRMET and the freezing-level panels of the prog charts depict. Teach the student to write the freezing level on the nav log next to the cruise altitude.

Frost (K3k). On cool, clear, calm nights the surface cools the adjacent air below its dew point; if the temperature is below freezing, the moisture deposits as frost rather than dew. Dew poses no threat; frost is a definite flight safety hazard — it disrupts the flow of air over the wing and can drastically reduce the production of lift, and increases drag, which combined can adversely affect the ability to take off. The aircraft must be thoroughly cleaned and free of frost before flight (PHAK ch. 12). This is the one K3 item your student meets on the ramp at 7 a.m. Teach it with a hand on the wing, and never let a student launch with "just a light coating."

Obstructions to visibility (K3l). Smoke, haze, dust, volcanic ash, mist, and fog. The mechanism to teach is the stable-air one above: particulates trapped under an inversion. The lesson-level consequence is that a haze layer with legal reported visibility can still hide the horizon — which turns an ordinary practice-area lesson into inadvertent instrument conditions for a student who was flying outside references.

Thunderstorms need moisture, unstable air, and a lifting action. The mature stage is the most hazardous — updrafts and downdrafts coexist, with heavy precipitation, lightning, and possible hail; rain reaching the ground marks its onset.

The Convective SIGMET criteria give you the objective vocabulary: surface winds greater than 50 knots, hail greater than or equal to ¾ inch, tornadoes, embedded or line thunderstorms, or heavy precipitation over 40 percent of a 3,000-square-mile region (PHAK ch. 13).

What you refuse, stated to the student as a rule with a reason: no training flight in the vicinity of a cell, because the hazard is not the cell — it is the gust front and downdraft outflow that reach well beyond the visible cloud, and because your student is low, slow, and configured in the pattern where there is no energy to trade. Datalink will not help; see the NEXRAD latency card. The correct instructional response to convection near the field is a ground lesson.

Change the question you ask.

• Rote question: "What does BKN008 mean?"
• Understanding question: "What is a ceiling, and why is it AGL?"
• Application question: "Given this METAR and this TAF, is the destination legal VFR at your ETA?"
• Correlation question: "You are 20 minutes out, the ceiling is dropping faster than the TAF said, and your alternate is behind you. What do you do and when did you decide it?"

AIH 4 warns that closed-ended questions "tend to evaluate the learner's understanding only at the rote level." Ask the last question every lesson. And require the student to brief you — the person who briefs is the person who learns.

That last row is the most important one in this task. If you always decide, the student learns that weather decisions come from an authority figure — and on the first solo there isn't one.

You are the external pressure. The student wants to fly, has paid for the lesson, is on a schedule, and believes you would not have shown up if the weather were a problem. Every one of those is a force pushing toward a launch that a solo pilot would have cancelled.

Mitigations that work:

• Ask before you answer. Require the student's go/no-go and reasoning first. AIH 1 warns that pilots should never make minimums less restrictive when planning a specific flight "or else external pressures will influence you" — the same trap operates on you when you're the one being watched.
• Publish your own instructor minimums and hold them visibly. Students calibrate on what you do, not what you say — the law of primacy again.
• Make the cancelled lesson productive. A ground lesson on the day's actual weather is worth more than a mediocre hour of pattern work, and it teaches that cancelling is a normal outcome rather than a failure.
• Watch the marginal-in-two-categories rule. AIH Appendix D: marginal in one category, be wary; marginal in two or more, do not go. Weather plus a tired student is two.

The standard is stated in your own ACS — AI.III.C.S1 through S3 of FAA-S-ACS-25 — and it is what you are training the student toward: use available aviation weather resources to obtain an adequate weather briefing, analyze the implications of the observed and forecast conditions, and correlate weather information to make a go/no-go decision.

Practically, before you sign a solo cross-country, the student must be able to, unprompted:

1. Work the standard-briefing checklist in order and say what each element means for this flight
2. Identify the adverse conditions and state which advisories apply and why
3. Give a personal-minimums-based go/no-go with a stated reason and a named alternate
4. State the in-flight triggers that would make them divert, and where they would go

That is also the 61.93(c)(3) determination you sign — that the student's preflight planning and preparation is correct and the student is prepared to make the flight safely under the known conditions. Weather is most of what "the known conditions" means.