5.4 Satellite Imagery, Moisture-Stability Analysis, and Forecast Integration

FAA Aircraft Dispatcher Certificate ADX

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1 Chapter 1: Regulations, Certification & Operational Control

1.1 Part 65 Subpart C: Certification, Eligibility & Currency 1.2 Operational Control & Dispatcher-PIC Joint Responsibility 1.3 Domestic, Flag & Supplemental Operations Framework 1.4 Dispatch Release Elements, Signatures & Recordkeeping 1.5 Regulations, Manuals, Crew Qualifications, and Source Control

2 Chapter 2: Atmospheric Physics, Pressure Systems & Fronts

2.1 Atmospheric Structure, Standard Atmosphere & Altimetry 2.2 Air Masses, Frontal Systems & Frontogenesis 2.3 Atmospheric Stability, Lapse Rates & Cloud Formation 2.4 Earth Motion, Regional Weather, Local Winds, and Water Phase Changes

3 Chapter 3: Aviation Weather Hazards & Severe Weather Avoidance

3.1 Structural and Induction Icing: Types, Accretion & Operations 3.2 Thunderstorms, Squall Lines, Microbursts & Low-Level Windshear 3.3 Clear Air Turbulence (CAT), Mountain Waves & Jet Streams 3.4 Low Ceilings, Fog Types & Visibility Restrictions 3.5 Hurricanes, Typhoons, Tornadoes, and Tropical Dispatch Hazards

4 Chapter 4: Weather Observations, Forecasts & Advisories Decoding

4.1 METAR and SPECI Surface Observations: Decoding & Operations 4.2 Terminal Aerodrome Forecasts (TAF): Groups & Timing 4.3 Pilot Weather Reports (PIREP): Coding, Severity & Urgent Alerts 4.4 In-Flight Advisories: AIRMETs, SIGMETs & Convective SIGMETs 4.5 Weather Collection, NWS Facilities, GFA, and EWINS

5 Chapter 5: Aviation Weather Charts & Upper-Air Analysis

5.1 Surface Analysis & Radar Summary Charts 5.2 Constant Pressure Analysis & Winds Aloft (FB) 5.3 Significant Weather Prognostic Charts (SIGWX) 5.4 Satellite Imagery, Moisture-Stability Analysis, and Forecast Integration

6 Chapter 6: Air Navigation, Airspace Architecture & Route Structure

6.1 National Airspace System: Classes, Rules & Special Use 6.2 Ground-Based Navigation Aids & Standard Service Volumes 6.3 Area Navigation (RNAV), GNSS/GPS, PBN & RNP Fundamentals 6.4 En Route Airways, SIDs, STARs & Chart Interpretation 6.5 Earth Coordinates, UTC, Chart Projections, and Flight Instruments 6.6 North Atlantic, Pacific, RVSM, and Global Navigation Differences

7 Chapter 7: Instrument Approaches, Minimums & Airport Operations

7.1 Precision Approach Systems: ILS Categories & Tolerances 7.2 Non-Precision Approaches, RNAV & Decision Minimums (MDA/DA) 7.3 Takeoff Minimums, Lower-Than-Standard & Takeoff Alternates 7.4 Holding Procedures: Patterns, Speed Limits & Timing

8 Chapter 8: Subsonic Aerodynamics & Jet Aircraft Performance

8.1 Subsonic Jet Aerodynamics: Lift, Drag & Flight Regimes 8.2 High-Altitude Flight: Mach Number, Buffet & Coffin Corner 8.3 Transport Turbine Engines: Thrust, Specific Fuel & Bleed Air

9 Chapter 9: Transport Category Takeoff & Landing Runway Analysis

9.1 Takeoff Performance Speeds & Balanced Field Concept 9.2 Takeoff Climb Segments & Obstacle Clearance Gradients 9.3 Landing Performance: Field Lengths, 60% Rule & Contamination

10 Chapter 10: En Route Performance, Driftdown Profiles & ETOPS Operations

10.1 One/Two-Engine-Inoperative En Route Net Profiles & Driftdown 10.2 Extended-Range Operations (ETOPS): Philosophy & Regulations 10.3 ETOPS En Route Alternates: Adequate vs. Suitable & Critical Fuel

11 Chapter 11: Aircraft Weight & Balance, Center of Gravity, and Loading

11.1 Transport Aircraft Structural Weight Limits: Definitions & Rules 11.2 Center of Gravity Computations: Datum, Arm, Moment & Index 11.3 Mean Aerodynamic Chord (%MAC) Computations & Stability 11.4 Payload-Range Analysis, Zero Fuel Weight Tradeoffs & Loading

12 Chapter 12: Destination Alternate Airport Selection & Weather Rules

12.1 Destination Alternate Selection: 91.169 & Part 121 1-2-3 Rule 12.2 Flag & Supplemental Operations Destination Alternate Rules 12.3 Derived Alternate Minimums: 1-Nav and 2-Nav Facility Rules

13 Chapter 13: Part 121 Fuel Planning, Reserves & En Route Re-Release

13.1 Part 121 Domestic Fuel Requirements: Reserves & Calculations 13.2 Part 121 Flag Fuel Requirements: 10% Reserve & Island Rules 13.3 Supplemental Fuel Requirements & Holding Fuel Management 13.4 Redispatch and En Route Re-release Procedures

14 Chapter 14: Transport Systems, Pressurization & MEL/CDL Procedures

14.1 Transport Jet Auxiliary Power, Electrical, Hydraulic & Pneumatic Systems 14.2 Cabin Pressurization, Rapid Decompression & Oxygen Requirements 14.3 Master Minimum Equipment List (MMEL), MEL & CDL Procedures 14.4 Flight Controls, Autoflight, Fuel, Oil, Brakes, and Fire Protection

15 Chapter 15: Hazardous Materials, Duty Regulations & Emergency Procedures

15.1 Dangerous Goods Carriage by Air (49 CFR Part 175) & NOTOC 15.2 Dispatcher Duty Limitations, Rest Requirements & Fatigue 15.3 Emergency Authority, Declaration & Diversion Decision-Making 15.4 NTSB Part 830 Accident Reporting & Wreckage Preservation 15.5 Security, Overdue Aircraft, and FAA Emergency Services

16 Chapter 16: Communications, ATC, and Flight Plan Procedures

16.1 Voice, Data Link, Position Reports, and Lost Communications 16.2 ATC Facilities, Separation, ICAO Flight Plans, and Traffic Management

17 Chapter 17: Human Factors and Practical Dispatch Applications

17.1 Dispatch Resource Management, Human Error, and Risk Decisions 17.2 Manual Flight Planning, PIC Briefing, Flight Watch, and Postflight Closeout

5.4 Satellite Imagery, Moisture-Stability Analysis, and Forecast Integration

Key Takeaways Explain This Topic AI

Visible imagery depends on reflected sunlight and does not directly measure turbulence or cloud-top altitude.

IR cloud-top temperature needs the atmospheric profile for a height interpretation.

Water-vapor imagery samples a broad layer rather than proving surface humidity or ceiling.

Soundings help assess stability, inversions, moisture layers, and multiple freezing levels.

No single model or graphic guarantees that a route is free of hazards.

Last updated: October 2026

Read the Atmosphere in More Than One Layer

Satellite and moisture-stability information fill important gaps between surface reports, radar, and forecast charts. The syllabus names satellite meteorology, tropopause information, composite moisture-stability charts, and other applicable products. A dispatcher needs to understand the physical quantity shown and the current product's scope, especially when a legacy named chart has been replaced by newer graphical or sounding tools.

Visible imagery

Visible satellite imagery uses reflected sunlight. It is valuable for cloud texture, boundaries, developing convection, snow/ice comparisons, and daytime fog patterns. Thick clouds often appear bright, while thinner clouds and clear surfaces differ in reflectance. Brightness is not a direct measurement of cloud-top height or turbulence intensity.

Visible imagery generally needs illumination. Darkness does not turn every thunderstorm into an “embedded” SIGWX cloud; embedded refers to concealment in cloud layers or haze under the product definition. At night, use infrared and other appropriate channels together with observations and forecasts. During low sun angles, shadows and viewing geometry can affect interpretation.

Infrared imagery

Infrared (IR) imagery estimates the temperature of emitting surfaces, often cloud tops or the surface where clear. Cold tops can indicate high, deep clouds, but temperature alone does not uniquely establish geometric height. The actual atmospheric temperature profile matters, and inversions or thin-cloud effects complicate simple assumptions.

Enhanced color palettes emphasize temperature ranges selected by the product. A red patch on one vendor's map need not have the same temperature or meaning as red on another. Read the legend before interpreting a color as severe convection. Cold anvil cloud can extend away from the strongest precipitation or updraft; a flight underneath or beside an anvil still needs hazard assessment.

Water-vapor imagery

Water-vapor channels sample moisture and temperature in broad atmospheric layers, with the exact sensitivity dependent on the channel and conditions. They reveal large-scale moist/dry patterns and upper-level circulation. A dark water-vapor region does not prove that surface air is dry or that an airport is free of fog. Nor does a moist signal establish supercooled liquid water at the airplane's altitude.

Use the displayed layer to identify a possible trough, dry intrusion, or moisture plume, then correlate it with pressure-height analysis, winds, radar, terminal forecasts, and PIREPs. The instrument senses radiation; the operational inference comes from interpreting that signal in context. Label uncertain inferences rather than presenting them as direct measurements.

Soundings and stability information

A radiosonde sounding or an applicable model sounding presents vertical temperature, dewpoint, and wind information. On a skew-T , temperature and dewpoint separation can identify relatively moist layers, while their profiles help evaluate inversions, lapse rates, freezing levels, and conditional instability. Moisture at one level is not the same as a surface ceiling measurement.

A composite moisture-stability product combines information useful for assessing moisture and instability. Legacy exam figures may use such a chart; current operations can use appropriate sounding, model, and graphical analyses. Identify the legend and valid time on the actual figure rather than claiming every historical product remains issued in its original format.

Pattern Possible implication Necessary crosscheck

Small temperature/dewpoint spread in a layer Cloud/moisture potential Observations, layer depth, actual lifting

• Strong low-level inversion Suppressed mixing, fog/LLWS risk Surface reports, winds across the layer
• Unstable lapse rate with adequate moisture Convective potential Lifting trigger, inhibition, storm forecasts
• Multiple freezing levels Complex precipitation/icing structure Sounding profile, reports, aircraft limitations
• Strong vertical wind variation Shear/turbulence concern PIREPs, advisories, turbulence guidance
• Freezing levels and precipitation type

A winter sounding can contain warm air aloft above a shallow subfreezing surface layer. Snow falling into the warm layer may melt, with refreezing or supercooling depending on the lower-layer depth and temperature. This supports assessment of ice pellets, freezing rain, and aircraft icing hazards. A surface temperature alone cannot identify the full vertical thermal structure.

For an aircraft descending from cruise, check the entire profile and expected cloud/icing layers rather than only the departure and arrival temperatures. An anti-ice performance penalty or an aircraft envelope restriction can affect route and altitude choices. Forecast freezing-level charts complement reports and advisories; they are not an unconditional statement that there is no icing above or below one contour.

Integrate observations and model guidance

Radar helps identify precipitation echoes, while satellite detects cloud and circulation patterns over larger areas. A radar-clear region can still contain icing, CAT, or clouds outside radar sampling. Satellite's cold cloud tops do not supply a legal alternate ceiling value. A surface observation gives airport conditions at its observation time but not the entire future route.

Models and analyses such as Current/Forecast Icing Products and Graphical Turbulence Guidance can support assessment. Read their forecast/analysis time and limitations. “Current” in a product name does not eliminate processing and dissemination delay. The FAA handbook emphasizes that modeled icing intensity is a broad indication and aircraft response depends on airframe characteristics.

Worked route briefing

A fictional route crosses a region with a moist upper-level plume, a surface front, a model sounding showing conditional instability, and a growing radar line. The dispatcher combines these signals with the Convective SIGMET text and storm motion. The useful conclusion is a credible developing convection risk along the route's arrival time, not a guarantee inferred from a single index.

Compare a northern reroute with a delayed departure, calculate the relevant fuel/performance differences using approved data, and evaluate alternate exposure to the same system. Brief the PIC on the selected corridor, remaining uncertainty, and the next update trigger. If the sounding is old or far from the route, explicitly limit the inference and obtain more relevant data. This is the practical skill of integrating complementary weather sources without promoting any one graphic into a universal safety guarantee.

Official References

Source check: 2026-10-12 . 2026 FAA Aviation Weather Handbook . For operational use, apply current issued authorizations and the assigned aircraft’s approved data.