How do you read a wind barb?

A wind barb is a line with feathers on one end. The line points in the direction the wind is coming FROM, and the feathers encode the speed: a half-feather is 5 knots, a full feather is 10 knots, and a filled triangle (pennant) is 50 knots. Add them up. A barb with one pennant and two full feathers is 50 + 20 = 70 knots.

What do the wind barb symbols mean?

Each symbol is a speed increment: short line (half-barb) = 5 kt, long line (full barb) = 10 kt, solid triangle (pennant) = 50 kt. A small open circle with no barb means calm wind. Combine the symbols on a single staff to read the total speed.

Which way does a wind barb point?

The staff of the barb points toward the direction the wind is blowing FROM, following meteorological convention. A barb pointing down toward the south means a north wind (wind coming from the north). The feathers always sit on the upwind end of the staff.

How do you read wind shear from wind barbs?

Stack the barbs from different altitudes (as on a Skew-T sounding). If the barbs change direction with height (veering or backing) and increase in speed, that is wind shear — the ingredient that lets storms organize and rotate. A sharp clockwise turn with height (veering) favors supercells.

How to Read Wind Barbs — Speed, Direction, and Shear

How to Read Wind Barbs — Speed, Direction, and ShearWind barbs encode both wind speed and direction at every point on SPC mesoanalysis charts, Skew-T soundings, and surface analyses. Cheat-sheet for half-feathers, full feathers, pennants, plus how to read shear from a stack of barbs.A wind barb is the meteorological symbol that encodes both wind speed and direction at a single map point. Wind barbs show up on SPC mesoanalysis charts (MLCAPE, bulk shear, SRH, STP) overlaid on the parameter shading, on Skew-T soundings down the right side, and on every surface analysis ever drawn. Once you can read them, every meteorological map gets twice as information-dense.The two pieces of information

Direction: The line (the "stem") points in the direction the wind is coming FROM. A barb whose stem points to the north is a "northerly wind" — air flowing FROM the north TO the south. The feathers always sit on the upwind end of the stem.

Speed: Encoded in the feathers / pennants attached to the upwind end of the stem. Always reported in KNOTS (1 kt ≈ 1.15 mph ≈ 1.85 km/h). Add up the feathers to get the wind speed.

Speed encoding cheat-sheetEach feather adds to the total. Combine to read the speed:

Open circle (calm): less than 1 knot

Bare stem (no feathers): 1–2 knots

Half feather (short): 5 knots

Full feather (long): 10 knots

Filled triangle (pennant): 50 knots

Examples by combination:

One full + one half = 15 kt

Two full + one half = 25 kt

One pennant = 50 kt

One pennant + two full + one half = 75 kt

Two pennants = 100 kt

Direction — "wind FROM, not TO"This trips up almost everyone the first time. The stem points in the direction the wind is COMING FROM, not where it is going. A barb whose feathers sit at the NW end means the wind is from the northwest — common parlance "a NW wind" or "northwesterly." The stem itself effectively points toward where the air is HEADED.Mnemonic: think of the feathers as the tail of an arrow that the wind is shooting toward you. The arrowhead end (the empty end of the stem) is where the air is going.Why knots and not mph?Knots are the international standard in aviation, marine, and meteorology — historic accident plus the convenience that 1 knot equals 1 nautical mile per hour, and a nautical mile is exactly one minute of latitude. Quick conversions to keep in your head:

10 kt ≈ 11.5 mph (light wind)

20 kt ≈ 23 mph (breezy)

35 kt ≈ 40 mph (severe-criteria gust threshold)

50 kt ≈ 58 mph (severe thunderstorm warning criterion)

65 kt ≈ 75 mph (hurricane / Category 1)

100 kt ≈ 115 mph (Cat 3 hurricane / strong tornadic supercell jet)

Reading a column of barbs (Skew-T / hodograph)On a Skew-T sounding, wind barbs stack vertically down the right side, one per altitude. Reading the stack from surface upward tells you about wind shear — the change in wind with height — which determines whether thunderstorms will be pulse, multicell, or supercell:

Veering (clockwise turning with height): Wind direction shifts clockwise as you go up — e.g. SE at the surface to S at 850 mb to SW at 500 mb to W aloft. Indicates warm-air advection (warmer air moving in). Classic supercell environment in the Northern Hemisphere — supports right-moving rotating storms.

Backing (counter-clockwise turning with height): Wind direction shifts counter-clockwise with height. Indicates cold-air advection. Less favorable for tornadic supercells; sometimes seen in left-moving "anti-cyclonic" storms.

Speed shear: Wind speed increases with height (longer feathers / more pennants on the upper barbs). 0–6 km bulk shear ≥ 35-40 kt is the rule-of-thumb threshold for organized supercells.

Unidirectional flow: Same direction at all heights. Storms tend to be linear / multicell (squall lines) rather than discrete supercells.

On the SPC mesoanalysis chartsEvery mesoanalysis tile in the dashboard (MLCAPE, 0–6 km bulk shear, 0–1 km SRH, STP) overlays surface wind barbs in orange on top of the parameter shading. Read them the same way as any other map: feathers point upwind, count feathers / pennants for speed, line orientation tells direction. Where surface winds converge (barbs pointing toward the same line) is where you'll see the most active convection initiation — these convergence zones are often co-located with surface boundaries (cold fronts, drylines, outflow).Where to read more

NWS Honolulu Wind Barb Information: weather.gov/hfo/windbarbinfo

NOAA JetStream Wind reference: weather.gov/jetstream/wind

NWS Houston ARTCC training Flight wind barbs page

SPC Mesoanalysis live charts: spc.noaa.gov/exper/mesoanalysis

Frequently asked questions

How do you read a wind barb?: A wind barb is a line with feathers on one end. The line points in the direction the wind is coming FROM, and the feathers encode the speed: a half-feather is 5 knots, a full feather is 10 knots, and a filled triangle (pennant) is 50 knots. Add them up. A barb with one pennant and two full feathers is 50 + 20 = 70 knots.
What do the wind barb symbols mean?: Each symbol is a speed increment: short line (half-barb) = 5 kt, long line (full barb) = 10 kt, solid triangle (pennant) = 50 kt. A small open circle with no barb means calm wind. Combine the symbols on a single staff to read the total speed.
Which way does a wind barb point?: The staff of the barb points toward the direction the wind is blowing FROM, following meteorological convention. A barb pointing down toward the south means a north wind (wind coming from the north). The feathers always sit on the upwind end of the staff.
How do you read wind shear from wind barbs?: Stack the barbs from different altitudes (as on a Skew-T sounding). If the barbs change direction with height (veering or backing) and increase in speed, that is wind shear — the ingredient that lets storms organize and rotate. A sharp clockwise turn with height (veering) favors supercells.

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