Meteogram Mastery – Decoding Temperature, Dewpoint, and Wind Barbs in One Glance
The meteogram is the dashboard of the atmosphere. While basic apps give you a cute icon of a sun or cloud, the meteogram gives you the raw data.
To predict the wingfoil wind, you need to master three lines: The Wind Barbs, The Temperature/Dewpoint spread, and the Pressure curve.
Decoding Wind Barbs
The "feathers" on the arrow tell the story of wind speed.
- Stick: The shaft points into the wind. If the stick points up, the wind direction is South (blowing North).
- Short Barb: 5 knots.
- Long Barb: 10 knots.
- Pennant (Triangle): 50 knots.
Example: A shaft with one long barb and one short barb means 15 knots. This is the entry to the 15–25 knots range.
The Gust Factor: Often, a meteogram will plot the gusts as a separate color (usually red) or as a "whisker" on the barb. Watch the gap. If the barb says 15 knots but the gust dot is at 30 knots, the wind gusts are violent.
Temperature vs. Dewpoint (The Spread)
This is the secret to spotting rain and fog.
- Temperature Line (Red): The air temp.
- Dewpoint Line (Blue/Green): The temperature at which water condenses.
The Spread Rule:
- Wide Gap (>5°C): Dry air. Good visibility. Strong thermal wind potential.
- Narrow Gap (<2°C): Humid air. Clouds forming.
- Lines Touching: Fog or Rain. 100% humidity.
For wingfoiling, you want a wide gap during the day. Dry air is denser and creates a cleaner wind gradient. If the lines touch, the rain will kill the wind (drag from falling water droplets).
Pressure Trends
The pressure line (usually black) tells you the future.
- Falling Pressure: A storm (Low) is approaching. Expect high wind and shifting wind direction.
- Rising Pressure: The storm is passing. The wind will stabilize but often rotate.
- Flat Pressure: Stable weather. ideal for light wind cruising or thermal wind cycles.
Summary
Stop looking at the "Partly Cloudy" icon. It means nothing. Look at the meteogram. If the barbs show 15 knots, the dewpoint spread is wide, and the pressure is steady, you have a guaranteed session.