Glossary of Terms

Complete dictionary of meteorological, nautical and technical terms used in WindTrackr and wind sports.

A

AEMET
State Meteorological Agency. Official Spanish organization responsible for professional weather prediction. Uses high-resolution numerical models (HARMONIE-AROME, ECMWF) and is the most reliable source for forecasts in Spain. WindTrackr integrates its official data.
Anemometer
Instrument that measures wind speed. Most common are cup anemometers that rotate with wind. Professional ones like Davis Vantage Pro 2 have accuracy of ±1 knot. Must be installed at standard height (10m) without obstructions in radius of 10× its height.
Atmospheric Pressure
Weight of air column over a point. Measured in hectopascals (hPa) or millibars (mb). Standard sea level: 1013 hPa. High pressure (>1020 hPa) = anticyclone = stable weather. Low pressure (<1000 hPa) = depression = wind and rain.

B

Beaufort Scale
Empirical scale of 0-12 that classifies wind intensity according to observable effects. Ex: Beaufort 4 = 11-16kt (moderate breeze, small waves), Beaufort 7 = 28-33kt (strong wind, white foam). Useful for visual estimation without instruments.

D

Drift
Unwanted lateral displacement caused by sea currents or wind. In kitesurfing, sailing with excessive drift indicates poor upwind technique or strong current. Always have visual reference point on coast to detect offshore drift (takes you away from beach) which is DANGEROUS.

E

ECMWF
European Centre for Medium-Range Weather Forecasts. Global meteorological model of worldwide reference, used by professional meteorologists. Resolution ~9km, forecasts up to 10 days. AEMET uses it as base model. More accurate than American models (GFS) in Europe.

F

Funnel Effect
Wind acceleration when passing through a geographical narrowing. The Strait of Gibraltar (14km between continents) accelerates any synoptic wind by ~30-50%. That is why Levante/Poniente are so intense in Tarifa compared to nearby areas.

G

Gusts
Sudden and brief increases in wind speed. Technical definition: maximum instantaneous speed in 10-minute period. Average-gust difference >10kt indicates turbulent wind (typical Levante). <5kt indicates laminar wind (typical soft Poniente). Gusts size your kite, not the average.

H

HARMONIE-AROME
High-resolution meteorological model (~2.5km) used by AEMET for local forecasts. Better than ECMWF for orographic effects (mountains, coasts) but only covers Spain. Updated every 3 hours with prediction up to 48h.

I

Isobar
Line on weather map joining points of equal atmospheric pressure. Close isobars = high gradient = strong wind. Closed circular isobars = center of high (anticyclone) or low (depression) pressure.

K

Knot
Nautical speed unit. 1 knot = 1 nautical mile per hour = 1.852 km/h. Used universally in marine and aeronautical meteorology. Quick conversion: 1 kt ≈ 0.5 m/s. Example: 20kt = 37 km/h = 10.3 m/s.

L

Levante
East wind (90°) characteristic of the Strait of Gibraltar. Formed by Mediterranean high pressure + Atlantic low. Warm, dry, very strong (30-50kt typical), extremely gusty, can last 3-10 days. Associated with clear skies. The king wind of Tarifa.

M

Microclimate
Local weather conditions that differ from general environment due to topographic effects. Example: one spot can have 10-15kt more than a nearby location due to dune shadows or funnel effects. WindTrackr hyper-local sensors capture these microclimates.

N

Numerical Model
Computer program that simulates the atmosphere using physical equations to predict weather. Divides planet into 3D cells and calculates evolution. Main ones: ECMWF (European, 9km), GFS (American, 13km), HARMONIE-AROME (Spanish, 2.5km).

O

Offshore
Wind blowing from land towards sea ("off coast"). DANGEROUS for sailing: takes you away from beach, makes return difficult, generates rip currents. Example: North on Spanish Mediterranean coast. Always verify direction before going out.
Onshore
Wind blowing from sea towards land ("towards coast"). Generally safe: pushes towards beach in case of problem. Can bring waves and chop. Example: Levante in Tarifa is partially onshore on east-facing beaches.
Orography
Terrain relief (mountains, valleys, dunes). Greatly affects local wind: mountains create shadows and accelerations, valleys channel flow. Coastal dunes can generate turbulence with certain wind directions but provide protection with others.

P

Poniente
West wind (270°) of the Strait. Formed by Atlantic depressions. Cool, humid, moderate (15-30kt typical), laminar, duration 1-3 days. Associated with cloudiness and possible rain. More technical and predictable than Levante. Favorite of intermediate riders.
Pressure Gradient
Atmospheric pressure difference between two points. Greater gradient, greater wind speed (air flows from high to low pressure). On weather maps, isobars (lines of equal pressure) very close together = high gradient = strong wind.

S

Sideshore
Wind blowing parallel to the coast. Ideal for kitesurfing/windsurfing: allows sailing perpendicular to wind (beam reach) without moving away from beach. Perfect for learning and most riding styles as it keeps you along the shoreline.
Spatial Resolution
Cell size used by a meteorological model. HARMONIE-AROME: 2.5km (sees local details). ECMWF: 9km (general view). A 500m kite spot can be between 4 model cells, that is why forecasts are never 100% accurate at micro scale.
Swell
Waves generated by distant winds, traveling hundreds of km. Long, orderly, periodic waves. Different from wind waves (local waves from current wind). Atlantic swell can reach Tarifa with Poniente even if local wind is moderate.
Synoptic
Related to large-scale weather systems (hundreds/thousands of km). Synoptic winds (Levante, Poniente) are generated by pressure configurations at peninsular/continental scale, opposite to local thermal breezes.

T

Thermal
Ascending current of warm air. On land, sun heats ground → air expands and rises. Generates coastal thermal breezes (sea breeze during day). Weak in Tarifa compared to synoptic winds, but perceptible in calms.
Thermal Breeze
Local wind generated by temperature differences between land and sea. By day: land heats more → air rises → sea breeze towards land. By night: land cools more → land breeze towards sea. In Tarifa, breezes are weak compared to synoptic Levante/Poniente.
Timestamp
Time mark indicating when a measurement was recorded. Critical in meteorology: 2-hour-old data may be obsolete. WindTrackr shows timestamp of each reading. Rule: data >45min = suspicious, >2h = ignore.
Turbulence
Irregularity in wind flow. Causes: obstacles (buildings, trees), complex orography, thermal instability. Manifests as strong gusts and abrupt direction changes. Difficult sailing and can break gear. Typical with Levante.

W

Weather Vane
Instrument indicating wind direction. Arrow that rotates freely pointing towards where wind COMES from (upwind). In professional stations it is mounted on the anemometer. Typical accuracy: ±5°.
Wind Chill
Thermal sensation: temperature perceived by body considering wind. Wind increases heat loss by convection. Example: 15°C with 30kt feels like 8°C. Crucial for choosing wetsuit thickness. WindTrackr does not currently calculate wind chill (future data).
Wind Direction
Origin from where wind COMES, expressed in degrees (0-360°) or cardinal points. North=0°/360°, East=90°, South=180°, West=270°. Levante = East wind (90°). Poniente = West wind (270°). Do not confuse with sailing direction.

Missing a term? Contact us and we will add it to the glossary.