A wind barb plot displays wind speed and direction at specific locations using standard meteorological barb notation. Each barb consists of a staff pointing in the direction from which the wind blows, with short barbs (5 knots), long barbs (10 knots), and triangular pennants (50 knots) attached to indicate speed. This internationally recognized symbology enables rapid interpretation of wind patterns across weather maps and atmospheric data visualizations.
""" anyplot.ai
windbarb-basic: Wind Barb Plot for Meteorological Data
Library: plotly 6.7.0 | Python 3.13.13
Quality: 81/100 | Updated: 2026-05-19
"""
import numpy as np
import plotly.graph_objects as go
# Data - Surface wind observations from a grid of weather stations
np.random.seed(42)
# Create a grid of observation points (simulating weather station network)
x_grid = np.arange(0, 10, 1)
y_grid = np.arange(0, 6, 1)
X, Y = np.meshgrid(x_grid, y_grid)
X = X.flatten()
Y = Y.flatten()
# Generate wind components (u: east-west, v: north-south) in knots
# Create a realistic wind pattern with some spatial coherence
base_u = 15 + 10 * np.sin(X * 0.5)
base_v = 5 + 8 * np.cos(Y * 0.8)
U = base_u + np.random.uniform(-5, 5, size=X.shape)
V = base_v + np.random.uniform(-5, 5, size=Y.shape)
# Include some calm winds (< 2.5 knots) for demonstration
calm_indices = [0, 25, 45]
U[calm_indices] = np.random.uniform(-1, 1, size=len(calm_indices))
V[calm_indices] = np.random.uniform(-1, 1, size=len(calm_indices))
# Include strong winds with pennants (50+ knots) for variety
strong_indices = [12, 38, 55]
U[strong_indices] = 40 + np.random.uniform(0, 15, size=len(strong_indices))
V[strong_indices] = 30 + np.random.uniform(0, 10, size=len(strong_indices))
# Wind barb parameters
barb_length = 0.35
barb_width = 0.14
# Collect all wind barb line segments
all_barb_x = []
all_barb_y = []
# Draw each wind barb inline
for i in range(len(X)):
x0, y0 = X[i], Y[i]
u, v = U[i], V[i]
speed = np.sqrt(u**2 + v**2)
# Calm wind (< 2.5 knots) - draw open circle
if speed < 2.5:
theta = np.linspace(0, 2 * np.pi, 20)
circle_r = barb_length * 0.25
cx = x0 + circle_r * np.cos(theta)
cy = y0 + circle_r * np.sin(theta)
all_barb_x.extend(list(cx) + [None])
all_barb_y.extend(list(cy) + [None])
continue
# Calculate direction (wind comes FROM this direction)
wind_dir = np.arctan2(-v, -u)
# Staff endpoint (pointing into the wind direction)
x_end = x0 + barb_length * np.cos(wind_dir)
y_end = y0 + barb_length * np.sin(wind_dir)
# Staff line
all_barb_x.extend([x0, x_end, None])
all_barb_y.extend([y0, y_end, None])
# Perpendicular direction for barbs (to the left of staff)
perp_dir = wind_dir + np.pi / 2
# Calculate number of pennants, full barbs, and half barbs
speed_knots = speed
pennants = int(speed_knots // 50)
remaining = speed_knots % 50
full_barbs = int(remaining // 10)
half_barbs = 1 if (remaining % 10) >= 5 else 0
# Position along the staff (from tip towards base)
spacing = barb_length * 0.12
current_pos = 0.95
# Draw pennants (triangular flags for 50 knots)
for _ in range(pennants):
px1 = x0 + current_pos * barb_length * np.cos(wind_dir)
py1 = y0 + current_pos * barb_length * np.sin(wind_dir)
current_pos -= 0.15
px2 = x0 + current_pos * barb_length * np.cos(wind_dir)
py2 = y0 + current_pos * barb_length * np.sin(wind_dir)
px_tip = px1 + barb_width * 1.2 * np.cos(perp_dir)
py_tip = py1 + barb_width * 1.2 * np.sin(perp_dir)
all_barb_x.extend([px1, px_tip, px2, px1, None])
all_barb_y.extend([py1, py_tip, py2, py1, None])
current_pos -= 0.05
# Draw full barbs (10 knots each)
for _ in range(full_barbs):
bx1 = x0 + current_pos * barb_length * np.cos(wind_dir)
by1 = y0 + current_pos * barb_length * np.sin(wind_dir)
bx2 = bx1 + barb_width * np.cos(perp_dir)
by2 = by1 + barb_width * np.sin(perp_dir)
all_barb_x.extend([bx1, bx2, None])
all_barb_y.extend([by1, by2, None])
current_pos -= spacing / barb_length
# Draw half barb (5 knots)
if half_barbs:
bx1 = x0 + current_pos * barb_length * np.cos(wind_dir)
by1 = y0 + current_pos * barb_length * np.sin(wind_dir)
bx2 = bx1 + barb_width * 0.5 * np.cos(perp_dir)
by2 = by1 + barb_width * 0.5 * np.sin(perp_dir)
all_barb_x.extend([bx1, bx2, None])
all_barb_y.extend([by1, by2, None])
# Create figure
fig = go.Figure()
# Add wind barbs as a single scatter trace with lines (thicker for visibility)
fig.add_trace(
go.Scatter(
x=all_barb_x,
y=all_barb_y,
mode="lines",
line={"color": "#306998", "width": 5},
name="Wind Barbs",
hoverinfo="skip",
showlegend=False,
)
)
# Add station markers at observation points
fig.add_trace(
go.Scatter(
x=X,
y=Y,
mode="markers",
marker={"size": 10, "color": "#306998", "symbol": "circle"},
name="Weather Stations",
hovertemplate="Station (%{x}, %{y})<br>U: %{customdata[0]:.1f} kt<br>V: %{customdata[1]:.1f} kt<br>Speed: %{customdata[2]:.1f} kt<extra></extra>",
customdata=np.column_stack([U, V, np.sqrt(U**2 + V**2)]),
)
)
# Layout with tighter axis range and improved legend positioning
fig.update_layout(
title={"text": "windbarb-basic · plotly · pyplots.ai", "font": {"size": 28}, "x": 0.5, "xanchor": "center"},
xaxis={
"title": {"text": "Longitude (°E)", "font": {"size": 22}},
"tickfont": {"size": 18},
"range": [-0.5, 9.8],
"dtick": 1,
"gridcolor": "rgba(0,0,0,0.1)",
"gridwidth": 1,
},
yaxis={
"title": {"text": "Latitude (°N)", "font": {"size": 22}},
"tickfont": {"size": 18},
"range": [-0.5, 5.8],
"dtick": 1,
"gridcolor": "rgba(0,0,0,0.1)",
"gridwidth": 1,
"scaleanchor": "x",
"scaleratio": 1,
},
template="plotly_white",
showlegend=True,
legend={
"font": {"size": 18},
"x": 0.02,
"y": 0.98,
"bgcolor": "rgba(255,255,255,0.9)",
"bordercolor": "#306998",
"borderwidth": 1,
},
margin={"l": 100, "r": 80, "t": 100, "b": 100},
annotations=[
{
"x": 0.02,
"y": 0.02,
"xref": "paper",
"yref": "paper",
"text": "<b>Wind Barb Key</b><br>○ Calm (<2.5 kt)<br>╲ Half barb = 5 kt<br>╲╲ Full barb = 10 kt<br>▲ Pennant = 50 kt",
"showarrow": False,
"font": {"size": 16, "family": "monospace"},
"align": "left",
"bgcolor": "rgba(255,255,255,0.95)",
"bordercolor": "#306998",
"borderwidth": 2,
"borderpad": 10,
"xanchor": "left",
"yanchor": "bottom",
}
],
)
# Save as PNG (4800x2700)
fig.write_image("plot.png", width=1600, height=900, scale=3)
# Save as HTML for interactivity
fig.write_html("plot.html", include_plotlyjs=True, full_html=True)
Part of Wind Barb Plot for Meteorological Data on anyplot.ai.