Meteorology

Overview

Meteorology covers atmospheric structure, processes, synoptic interpretation, and severe weather concepts, with emphasis on reading plots and reasoning from first principles.

Atmospheric structure and energy

• Layers: troposphere (weather), tropopause, stratosphere (ozone), mesosphere, thermosphere; temperature profiles and inversions.
• Energy balance: solar shortwave in, terrestrial longwave out; albedo; greenhouse effect (qualitative radiative transfer).
• Stability: DALR (~10 °C/km) vs SALR (~6 °C/km, variable); environmental lapse rate (ELR). Stable vs unstable stratification; lifting condensation level (LCL) concept.

Moisture and phase change

• Humidity measures: specific humidity, mixing ratio, relative humidity; dew point and temperature relations.
• Cloud formation: lifting mechanisms (orographic, frontal, convective, convergence); cloud types by altitude and morphology.
• Precipitation processes: collision–coalescence (warm rain), Bergeron–Findeisen (ice‑phase). Freezing rain vs sleet setup (warm nose aloft).

Dynamics and circulation

• Pressure, wind, and forces: PGF, Coriolis, friction; geostrophic and gradient wind approximations.
• Synoptic patterns: cyclones/anticyclones; fronts (warm, cold, stationary, occluded); jet stream and baroclinicity.
• Local circulations: sea/land breezes, mountain/valley winds.

Analysis tools

• Station models: decode temperature, dew point, wind barbs, pressure/ tendency, present weather.
• Maps and charts: surface analyses, 500‑mb height fields (troughs/ridges), thickness; QG concepts (vorticity advection).
• Soundings (skew‑T/log‑p): temperature, dew point, winds with height; CAPE/CIN (qualitative), inversion identification; LCL/LFC/EL concepts.

Severe weather and hazards (qualitative)

• Thunderstorms: single‑cell, multicell, supercell; ingredients (lift, instability, moisture, shear); gust fronts and outflow boundaries.
• Lightning, hail, downbursts; tornado basics (mesocyclone context); squall lines and bow echoes.
• Winter weather: frontogenesis, deformation zone; snow vs mixed precip setups; lake‑effect processes.

Climate and variability

• ENSO: El Niño/La Niña patterns and typical teleconnections; PDO/AMO (conceptual).
• Climate vs weather distinction; persistence and anomalies; climatological means.

Worked micro‑examples

1. Front identification from station plots

• Sharp temperature gradient, wind shift from southerly to westerly, pressure trough, and cloud/precip line → likely cold front.

2. Skew‑T inversion

• Strong low‑level inversion with dry air aloft → suppressed convection; morning fog potential if surface saturated.

3. 500‑mb interpretation

• Trough axis and negative vorticity advection ahead of ridge → subsidence and clearing; positive advection ahead of trough → ascent potential.

Pitfalls

• Misreading wind barbs (units of knots) and confusing temperature/dew point positions.
• Assuming RH tells moisture content without temperature context.
• Ignoring stability when forecasting convective potential.

Practice prompts

• Decode a station model; identify front type and frontal zone motion.
• Interpret a skew‑T to assess instability and inversion layers.
• Describe expected weather downstream of a deepening surface cyclone with a trailing cold front.

References

• SciOly Wiki – Meteorology: https://scioly.org/wiki/index.php/Meteorology

Satellite and radar interpretation

Satellite imagery turns thermodynamic and microphysical structure into patterns. Visible bands show reflected sunlight and resolve fine texture but fail at night; infrared channels convert brightness temperature to cloud‑top temperature—cold, high clouds appear bright in IR grayscale; water vapor bands track mid‑ to upper‑tropospheric moisture and flow even without clouds. Learn canonical signatures: overshooting tops and cold‑U features over strong updrafts, transverse banding in jet streak outflow, dry slots wrapping into mature cyclones. Radar reflectivity maps hydrometeor concentration and size; velocity reveals radial wind and shear; dual‑pol products distinguish rain/hail/snow and identify debris in tornadic signatures. Place imagery in synoptic context—front positions, jet streaks, and low‑level jets—to reason from cause to observed pattern.

QG and frontogenesis (qualitative)

Quasi‑geostrophic ideas connect forcing to vertical motion: differential vorticity advection and temperature advection create ascent or descent through Q‑vector convergence/divergence. Ahead of troughs and left‑exit/right‑entrance regions of jet streaks, QG ascent favors cloud and precipitation development. Frontogenesis sharpens temperature gradients via deformation and convergence; the balanced response is a thermally direct circulation with ascent on the warm side and descent on the cold side, enhancing clouds and banded precipitation. On maps, look for tightening isotherms, confluence, and ageostrophic wind components that cross isotherms toward colder air. Use these cues to narrate a coherent evolution from forcing → vertical motion → clouds/precip.