ICAO Weather Scenarios

Adverse meteorological events are among the most frequently tested situations in the ICAO Aviation English assessment. Raters evaluate how clearly pilots describe severe atmospheric hazards, justify tactical route diversions, communicate windshear or icing encounters to ATC, and analyze the operational consequences of contaminated runways in plain English.

This page details core weather scenario categories, standard radiotelephony deviation requests, decision-making frameworks, and model speaking responses to help pilots achieve ICAO Level 4, Level 5, or Level 6.

Step 1: The 4-Step Weather Scenario Analysis Framework

When presented with a weather scenario in the oral exam, organize your response logically to show fluency, structural control, and operational sound judgment:

• 1. Identify the Meteorological Hazard: Name the specific phenomenon (e.g., squall line, clear air turbulence, freezing rain, radiation fog).
• 2. Analyze Operational Threats: Explain the direct impact on aircraft aerodynamics, visibility, braking performance, or fuel burn.
• 3. Detail Crew Actions & Mitigation: Outline tactical decisions (e.g., radar tilt management, anti-ice activation, speed adjustments, holding).
• 4. Coordinate with ATC & Ground: Transmit precise weather reports (PIREPs), request deviations, or initiate an alternate diversion.
• ICAO Weather Topics
• ICAO Scenario Explanation
• ICAO Problem Solving

Step 2: Core Weather Scenario Categories

Examiners use listening audio tracks, picture tasks, and situational prompts based on hazardous weather challenges:

Severe Thunderstorms & Microburst Encounters

• embedded cumulonimbus (CB) cells requiring rapid lateral deviations around convective activity
• reactive or predictive windshear alerts on short final triggering an immediate go-around / missed approach
• hail encounters causing windshield crazing, radome damage, and pitot-static sensor blockages
• ICAO Weather Vocabulary
• Weather Picture Description
• ICAO Emergency Scenarios

Severe In-Flight Icing & Winter Ground Operations

• rapid ice accretion on leading edges and engine nacelles causing loss of lift and airspeed decay
• contaminated taxiways and runways leading to reduced braking action and directional control difficulties
• calculating holdover times (HOT) during active freezing precipitation prior to take-off
• Technical Failure Scenarios
• Airport Picture Description
• Weather Safety Discussion

Low Visibility Operations (LVO) & Fog

• radiation fog lowering runway visual range (RVR) below CAT I/II minimums at destination
• loss of visual references below decision height requiring an immediate missed approach
• managing complex surface movements during low-visibility taxi procedures with illuminated stop bars
• Runway Picture Description
• ICAO Airport Topics
• ICAO Incident Description

Clear Air Turbulence (CAT) & Mountain Waves

• unforecast severe turbulence at cruising altitude causing cabin injuries and altitude excursions
• standing mountain waves creating extreme downdrafts and airspeed fluctuations near high terrain
• broadcasting urgent PIREPs and coordinating altitude changes to find smooth air
• Passenger Emergency Scenarios
• Passenger Topics
• Flight Operations Discussion

Step 3: Communicating Weather Situations & Deviations to ATC

Deliver clear, concise radio calls to request deviations, report severe turbulence, or advise landing inability:

• Requesting Storm Deviation: "Radar, FastAir 410, request heading 320, 25 miles right of track for weather avoidance, solid line of convective cells ahead."
• Reporting Severe Windshear: "Tower, Airway 715, reporting severe windshear on final approach runway 26L, lost 20 knots at 500 feet, executing go-around."
• Reporting In-Flight Icing (PIREP): "Control, Carrier 305, reporting moderate to severe rime icing between flight level 140 and 180, request immediate climb to flight level 220."
• Advising Inability Due to Surface Limits: "Tower, due to crosswind component exceeding aircraft limits on runway 09, we are unable to land; request holding or diversion to alternate."
• ICAO Interaction
• ICAO Request Phrases
• ATC Communication Topics

Step 4: Weather Decision-Making & Diversion Strategy

When analyzing scenario prompts involving marginal or unforecast weather, evaluate your options methodically:

• 1. Assess Reserve Fuel vs. Holding Time: Calculate how long the aircraft can remain in the hold waiting for weather improvement before divert fuel is reached.
• 2. Review Alternate Weather Conditions: Confirm that the selected alternate aerodrome has stable weather above landing minima and adequate crosswind margins.
• 3. Manage Aircraft Performance: Evaluate landing distances on wet, snow-covered, or icy runways with degraded braking action.
• 4. Coordinate Timely Action: Avoid unnecessary delays and initiate the diversion before dipping into mandatory final reserve fuel.
• ICAO Diversion Topics
• ICAO Diversion Scenarios
• ICAO Fuel Topics
• ICAO Fuel Scenarios

Step 5: Follow-Up Weather Scenario Discussion Questions

In Part 4 of the speaking test, examiners ask detailed questions regarding aeronautical decision-making, microburst hazards, and safety management:

• Why is the decision to execute an immediate go-around critical when encountering unexpected windshear?
• How should flight crews balance schedule commitments against deteriorating destination weather?
• What are the primary hazards associated with taking off with contaminated wing surfaces?
• How has modern airborne weather radar technology improved tactical flight routing and safety?
• Under what circumstances should a captain divert immediately rather than enter a holding pattern?
• Weather Safety Discussion
• Pilot Decision Making Discussion
• Aviation Safety Discussion
• ICAO Speaking Part 4 Discussion