PPL MonkeyPPL Monkey
de
MeteorologyLektion 30 von 48
30/48Thunderstorms

Types

Lesezeit ca. 2 min·
en
Sprache wechseln (DE)

Thunderstorm types

Thunderstorms are classified by trigger mechanism: heat (air-mass), frontal, advective, orographic.

Source: WMO; AMS Glossary; DWD; FAA AC 00-6B.

1. Heat / air-mass thunderstorm

High temperature, high humidity, high-reaching instability conditions promote the development of heat thunderstorms:

  • Diurnal-cycle dependent: peak in afternoon/evening.
  • Trigger: sun warms ground → thermal convection → Cu → Cb.
  • Heat thunderstorms do not require a SIGMET ("isolated heat thunderstorms do not require a SIGMET").

In the afternoon and evening, heat thunderstorms preferably develop over land masses.

2. Frontal thunderstorm

The development of frontal thunderstorms is possible at any time of the day with advection of high-reaching cold air:

  • Trigger: fast cold front under warm humid air.
  • Time: any time (not diurnal-cycle bound).
  • Form: often lines (squall line).

A cold front is most favourable to the development of thunderstorms in summer.

Thunderstorms in Central Europe frequently occur in maritime tropical air advected from Biscay and the Mediterranean.

3. Advective thunderstorm (cold-air advection)

Showers and thunderstorms need to be expected when moist air (mP) flows over a hot surface in summer:

  • Cold moist upper air (mP) over warm ground.
  • Strong instability → convection → showers/thunderstorms.

4. Orographic thunderstorm

The Central German Uplands can cause orographic thunderstorms because factors beyond just elevation — such as moist unstable air masses, prevailing winds, and topographic forcing — can trigger convective uplift and storm development even in moderate mountain ranges:

  • Mountain effect forces lift.
  • Combined with thermal or frontal triggers.

Seasonal maxima

Autumn has the maximum thunderstorm activity over the North and Baltic Sea — warm seas, cold upper air → strong instability.

Unstable air = thunderstorm potential

Thunderstorms can occur in an unstable air mass because it promotes strong vertical convection, leading to cumuliform cloud development and potential precipitation.

An unstable air mass is characterized by convection where ascending air parcels remain warmer than surroundings, fostering thermal convection, cumulonimbus (Cb) cloud formation, showers, and thunderstorms.

Klima-Atlas*; FAA AC 00-6B Aviation Weather; FAA-H-8083-25B PHAK Ch. 12.*

Fertig gelesen?
Melde dich an, um deinen Fortschritt zu speichern.