ICAO Weather Topics

Meteorological phenomena and weather hazards represent one of the largest thematic areas in the ICAO Aviation English assessment. Raters evaluate a pilot's ability to decode weather reports, describe adverse atmospheric conditions in plain English, negotiate weather deviations with ATC, and discuss operational decision-making related to thunderstorms, icing, and low visibility.

This page covers essential aviation weather vocabulary, typical weather-related operational scenarios, standard ATC deviation phrases, and model discussion questions to help pilots achieve ICAO Level 4, Level 5, or Level 6.

Step 1: Essential Aviation Weather & Meteorological Vocabulary

Using exact meteorological and operational terms rather than generic language ensures clear communication and higher vocabulary precision scores.

• Convective Weather & Wind: cumulonimbus (CB), towering cumulus (TCU), microburst, windshear, gust front, squall line, tailwind exceedance, crosswind limits
• Turbulence & Visibility: clear air turbulence (CAT), mountain wave activity, mechanical turbulence, dense fog, mist, haze, runway visual range (RVR), vertical visibility (VV)
• Icing & Winter Phenomena: rime ice, clear ice, mixed icing, freezing rain (FZRA), freezing fog, freezing drizzle, slush, standing water, snowdrifts
• Contaminated Surface Conditions: braking action (good, medium, poor, unreliable), friction coefficient, aquaplaning / hydroplaning, rubber deposits
• ICAO Weather Vocabulary
• ICAO Aviation Vocabulary
• ICAO Airport Vocabulary

Step 2: Common Weather Scenarios in ICAO Exams

Examiners use listening audio tracks, picture descriptions, and role-plays based on hazardous atmospheric conditions. Prepare clear explanations for each situation:

Thunderstorms, Microbursts & Windshear Encounters

• detecting convective storm cells on airborne weather radar and requesting lateral diversions
• experiencing reactive or predictive windshear alerts during final approach or take-off roll
• executing immediate windshear escape maneuvers and reporting conditions (PIREP) to ATC
• ICAO Weather Scenarios
• Weather Picture Description
• ICAO Incident Description

In-Flight Icing & De-icing Operations

• airframe structural icing leading to lift degradation, increased drag, and airspeed decay
• pitot-static probe icing causing unreliable or erratic airspeed and altitude indications
• winter de-icing/anti-icing fluid application and calculating holdover time (HOT) on the ramp
• Technical Problem Topics
• Airport Picture Description
• ICAO Emergency Scenarios

Low Visibility Operations (LVO) & Fog

• operating under CAT II or CAT III instrument approach procedures during dense radiation fog
• managing low-visibility taxi procedures, illuminated surface markings, and runway stop bars
• initiating a missed approach / go-around when visual references are not acquired at decision height (DH)
• Runway Picture Description
• ICAO Diversion Scenarios
• ICAO Diversion Topics

Step 3: Communicating Weather Situations to ATC

Clear radio phraseology is essential when requesting deviations around active weather cells or reporting hazardous conditions:

• Requesting Weather Deviation: "Radar, FastAir 620, request heading 040, 20 miles right of track for weather avoidance, storm cell directly ahead."
• Reporting Windshear / Turbulence: "Tower, FastAir 620, reporting windshear on final approach runway 27, lost 15 knots at 400 feet, executing go-around."
• Inquiring About Runway Conditions: "Tower, request latest runway visual range (RVR) and braking action report for runway 09 Left."
• Advising Inability to Comply: "Unable to descend to flight level 180 due to severe icing reported in the cloud layer; request remaining at flight level 220."
• ICAO Interaction
• ICAO Request Phrases
• ICAO Clarification Phrases
• ATC Communication Topics

Step 4: Weather Decision-Making & Risk Evaluation

Structure your responses during problem-solving tasks by systematically evaluating the operational trade-offs of weather hazards:

• 1. Identify the Meteorological Threat: Determine the exact hazard (e.g., squall line, microburst alert, below-minima RVR, freezing drizzle).
• 2. Evaluate Aircraft Capabilities: Check de-icing/anti-icing equipment status, autoland capability, crosswind limits, and required stopping distance.
• 3. Review Operational Margins: Assess fuel reserves available for holding while waiting for storm cells to clear the aerodrome.
• 4. Decide & Action: Execute a timely go-around, initiate an en-route diversion to a clear alternate, or negotiate a new arrival route with ATC.
• ICAO Problem Solving
• ICAO Speaking Part 3 Problem Solving
• ICAO Decision Making Practice
• Pilot Decision Making Discussion

Step 5: Follow-Up Weather Discussion Questions

In Part 4 of the speaking assessment, examiners ask in-depth questions regarding weather decision-making, microburst hazards, and pilot psychology.

• What are the most dangerous meteorological hazards encountered during the approach and landing phase?
• How should flight crews balance schedule commitments against marginal destination weather?
• What are the key differences between de-icing and anti-icing procedures during ground operations?
• How has modern airborne weather radar technology improved tactical flight planning and avoidance?
• Why is the decision to execute an immediate go-around critical when encountering unexpected windshear?
• Weather Safety Discussion
• Aviation Safety Discussion
• Flight Operations Discussion
• ICAO Speaking Part 4 Discussion