Thunderstorms (TS)

Thunderstorms are among the most complex and dangerous weather phenomena in aviation. They are not just rain and lightning; they are a "factory" of multiple atmospheric hazards that can affect aircraft safety and structural integrity.

How are they reported (METAR/TAF)?

Thunderstorms are expressed using specific codes:

• TS: Short for Thunderstorm.
• CB: Short for Cumulonimbus, the cloud type responsible for thunderstorms.
• +TSRA: Thunderstorm with heavy rain.
• VCTS: Thunderstorm in the vicinity.

Example: METAR HECA 131200Z 24015KT 4000 TSRA FEW020CB SCT030 25/18 Q1012

• In this report, we see TSRA (Thunderstorm and Rain) and CB (Cumulonimbus clouds).

---

Main Hazards to Aviation ⚠️

1. Severe Turbulence: Violent updrafts and downdrafts inside and around the cloud.
2. Hail: Can cause significant damage to the airframe, windshields, and engines.
3. Lightning: While aircraft are designed to withstand strikes, they can interfere with electronic systems and cause crew stress.
4. Microbursts: Sudden and extremely powerful downdrafts that lead to rapid loss of altitude near the ground.
5. Icing: Cumulonimbus clouds contain large amounts of supercooled water that freezes instantly upon contact with the aircraft.

---

Standard Pilot Procedures

• Avoidance: The golden rule is to never enter a CB cloud. It is recommended to stay at least 20 nautical miles away, especially at high altitudes.
• Weather Radar: Pilots rely on the aircraft's radar to identify high-intensity areas (red color) and navigate around them.
• Storm Penetration (If unavoidable): In very rare cases, specific procedures are followed, such as reducing speed to the Turbulence Penetration Speed and maintaining aircraft attitude rather than altitude.

💡 Navigational Tip: A thunderstorm that looks "small" on the radar might hide violent activity behind it. Always choose the upwind side when navigating around a storm to avoid hail and extended turbulence.