Conceptual framework

The advanced pilot works in three layers: (1) synoptic (H / L, fronts, jets), (2) * mesoescalar * * (waves, convergences, breezes), (3) * local * * (triggers, shear, investments). Each numerical model best solves one scale or another.

WMO classification and thermodynamic meaning

  • High (6-13 km): ice crystals. Ci → Cs → As in 18-36 h = warm front approaching.
  • Medias (2-6 km): Ac castellanus with K-index > 30 in continental summer = Cb probability > 70%.
  • Vertical development: Cu (CCL / LFC), Cb (EL to tropopause).

Thermodynamic cycle of the cumulus

The plot follows:
- Dry adiabatic Γd = 9.8 ° C / km to LCL
- Td falls to ~ 1.8 ° C / km, convergence 8 ° C / km
- LCL-125 × (T-Td) meters (Espy)
- CCL (real warming level) = 50-300 m above LCL
- Up LCL: saturated adiabatic 6 ° C / km (low) at 7 ° C / km (high)

If at the height of T _ plot > T _ environment → CAPE positive, accelerate.

Cycle (Byers & Braham 1949):
1. Cumulus stage: ascending dominan, 10-20 min
2. Mature: ascending + descending coexist, 15-30 min
3. Dissipating: descending dominan, 10-20 min

Stability indices

CAPE (J / kg):
- < 500: weak thermal
- 500-1000: classic XC
- 1000-2500: powerful day, watch OD
- 2500-4000: Cb probable, morning window
- > 4000: do not fly

Lifted Index (LI) (° C):
- ≥ + 2: stable
- 0 to + 2: slightly stable
- -2 to 0: moderately unstable, humble-mediocris
- -4 to -2: strongly unstable, likely
- < -4: high risk Cb

K-Index: > 30 = Cb serious
Showalter: similar to LI since 850 hPa
Total Totals (TT): (T850 + Td850) − 2 · T500. > 50 severe.
Thermal Index (TI): T _ ambience − T _ plot at given height. IT = -2 = thermal arrive with + 2 ° C floating. XC looks for IT ≤ -3 up to ceiling.
Vertical gradient: > 7 ° C / km in convection layer → favourable conditional instability.
BRN: CAPE / shear energy. 10-45 supports supercells.

Sound (Skew-T)

Keys:
- Curve T (red) and Td (green): distance = saturation.
- Investments: dT / dz > 0 segments. Thermal roof.
- CCL: from surface Td by mixing ratio to cutting T.
- LFC: where plot no longer needs push.
- EL: Cb ceiling.
- CIN (J / kg): > 100 reprimand morning convection. CIN high + CAPE high = Cb explosive late.
- Hodógrafa: vector wind vs height. Curvature = directional shear.

Cizaladura and mountain wave

Vertical tilting ΔV / Δz:
- < 5 m / s / 1000m: clean thermal
- 5-10: tilted thermal
- > 10: broken thermal, hazard < 500 m AGL

Mountain wave: wind > 25 kt perpendicular ± 30 °, medium stability, neutral layer below. Wave length 5-20 km. Manifesta with ACSL.

Rotors: horizontal circulations with severe to extreme turbulence. Sierra Nevada: ± 15 m / s in meters. Incompatible with free flight.

Foehn gap: a leeward, dry adiabatic descending (+ 10 ° C / km, Td -6 ° C / km). ΔP > 10 hPa / 100 km range = severe foehn.

Broken Dynamics

  • Anabatic: up to 5 m / s, thickness 200-500 m, 2-3 h after orth.
  • Katabática: 3-6 m / s typical, glaciers / valleys up to 15 + m / s. 01-03 h peak.
  • Marina: front advances 20-50 km inland, Δθ 2-5 K. Convergence creates cumulation online.
  • Convergences: abrupt change of surface direction, abnormal alignment of cumuli, in RASP ascends 0.5-1.5 m / s in large areas.

Numeric models

  • GFS (NCEP): 13 km global, 6h, 384h horizon. Poor orography, synoptic > 48h.
  • ECMWF IFS: 9 km, best determinist global.
  • ICON (DWD): 13 km global, 6.5 km EU, 2 km Germany. Excellent convection.
  • AROME (MF): 1.3 km Europa W. Solves breezes. Meteo- Paragliding base.
  • WRF / RASP: 2-4 km regional. Soaring parameters: BL top, BL max up, star, OD.

24 h surface wind accuracy: AROME / ICON-D2 ± 2 m / s, ± 20 °. At 72h global models differ; use ensembles.

Satellite and radar

  • Visible (VIS): 0.6 µm, day. Cumuli streets, breeze fronts.
  • Infrelta (IR): 10.8 µm. Top < -40 ° C = mature Cb. Overshooting tops = severe.
  • Water vapor (WV): 6.2-7.3 µm. Jet streaks, synoptic convergence.
  • RGB convection (EUMETSAT): Bright yellow Cb.
  • Radar (dBZ): > 35 moderate, > 50 likely hail, > 60 severe.

Quantitative hazards

  • Cb: 20 km security. The 5 NM aeronautical rule is insufficient for free flight.
  • Microburst: 1-4 km, < 15 min, radial gradient > 10 m / s in 1 km.
  • Gust front: 5-50 km from Cb, 30-80 km / h advance, Δv 15-30 m / s, ΔT 5-10 ° C.
  • OD: 3 / 8 → 7 / 8 in 90 min. Close XC and land.
  • cloud suction: + 8 to + 15 m / s inside base confreres. Big ears + bar + 90 ° to the wind.

Advanced XC Protocol

  1. D-3 to D-1: GFS / ECMWF, jet, H / L, fronts.
  2. D-1: AROME + meteograms Meteoblue. Set IT window = -2 → closure (OD, shear, front).
  3. D-0 sunrise: sound real, AROME 06z, satellite.
  4. Take off: direct observation 30 min. Cross with prognosis.
  5. In flight: dries by wind every 100 m, streets of actual clouds vs planned, alarm 300 m low base.
  6. Close: stay away from confreres > 1h before OD.

Checklist NO-GO

  • Wind 850 hPa > 35 kt in ridge
  • Surface raches > 40 km / h
  • LI < -6 and CAPE > 3000 J / kg
  • ACSL confirmed + foehn gap
  • IR tops < -50 ° C radius 50 km
  • Mammatus visible from take-off
  • Pressure falling > 3 hPa / 3h
  • T-Td < 4 ° C with negative LI

Professional sources

  • Windy (multimodel, hodographs)
  • Meteoblue (soaring parameters, OD probability)
  • Meteo- Paragliding (AROME 1.3 km)
  • SkySight (WRF 2 km, task planner)
  • XC Skies (WRF 4 km)
  • RASP BLIPMAPs (clubs)
  • Sounds: U. Wyoming, Ogimet
  • Satellite: EUMETSAT, RAMMB / CIRA
  • Radar: AEMET, Meteociel, RainViewer

Synthesis

A good day is recognized for consistency between 4 sources: mesoescalar model, real sound, sky observation, variogram in first thermal. When four points the same, it opens. When they disagree, atmosphere in transition, margins are narrowed. Weather is learned by flying with a trained look and respecting the thresholds set on the ground.