What you will learn
A wind profile drawn as a path
A hodograph plots the horizontal wind at several heights, then connects those wind vectors into a curve. The result shows how wind speed and direction change through the atmosphere.
The chart may look abstract because height is not placed on a normal vertical axis. Height is carried along the curve through labels or color segments. A point near the beginning may represent the surface, while later points mark 1 km, 3 km, 6 km, and higher levels.
A hodograph does not replace the wind barbs on a sounding. It reorganizes the same information so vector differences, curvature, and storm-relative flow are easier to see.
Explore a Hodograph
Choose a concept or move the storm-motion point. The chart and all four explainer corners update together.
Illustrative wind profile for learning. This is not a current or forecast hodograph.
Read one wind point
The center of the plot represents zero wind. Distance from the center represents wind speed. A point 30 knots from the origin describes a 30-knot wind vector.
Direction comes from the point’s position around the compass axes. Meteorological wind direction names where the wind comes from, while the plotted vector commonly points toward where the air is moving. Check the labels on the specific product until that reversal becomes familiar.
Practice with isolated points before reading the curve. If you cannot translate a point back into a wind barb, the overall shape will be easy to misread.
Illustrative wind profile for learning. This is not a current or forecast hodograph.
The curve shows vertical wind shear
Vertical wind shear is the vector difference between winds at two levels. On a hodograph, that difference is the straight line connecting the two level points. Its length represents the magnitude of the bulk shear through that layer.
The full curve can be much longer than the endpoint-to-endpoint vector. A curved or irregular path contains directional changes that a single bulk-shear number cannot preserve. That is why two environments with the same 0 to 6 km bulk shear can present different storm-relative flow.
Read named layers. The surface to 1 km segment answers a different question from the 0 to 6 km segment. Always find the height markers before describing a curve as long, short, straight, or curved.
Illustrative wind profile for learning. This is not a current or forecast hodograph.
Length and organization
A larger vector change through the storm depth can help an updraft remain separated from precipitation and can support organized convection. This is one reason deep-layer shear is a common part of storm-mode forecasts.
Length alone does not select one storm mode. The orientation of the initiating boundary, the distribution of buoyancy, cold-pool behavior, and the number of storms also matter. Strong shear can support supercells, organized lines, or other structures depending on how convection forms.
Do not assume every long hodograph is favorable for surface-based storms. A large part of the vector change may occur above the inflow layer, or the low-level air may be too stable for storms to ingest.
Illustrative wind profile for learning. This is not a current or forecast hodograph.
Curvature and horizontal vorticity
Wind changing with height creates horizontal vorticity, which can be pictured as tubes of spin in the environment. The orientation of that spin relative to storm inflow affects how efficiently it can be tilted into an updraft.
Curvature in the hodograph often indicates that the orientation of shear is changing with height. When the storm-relative wind aligns with the horizontal vorticity, more of that vorticity is streamwise and can flow along its own spin axis toward the updraft.
A curved hodograph is not a tornado forecast. The curve must be evaluated with a realistic storm motion, suitable instability, and an inflow layer the storm can access.
Illustrative wind profile for learning. This is not a current or forecast hodograph.
Add storm motion
Environmental winds are ground-relative. A moving storm experiences those winds after its own motion is subtracted. Plotting a storm-motion point lets you draw a vector from that point to each place on the hodograph. Those are storm-relative wind vectors.
Move the storm-motion point and every storm-relative vector changes. A right-moving supercell may experience stronger or more favorably aligned low-level inflow than a storm moving with the mean wind in the same environment.
Forecast products often plot estimated right-moving and left-moving storm motions. Treat them as starting estimates. Boundaries, storm interactions, and evolving storm structure can change actual motion. Once storms exist, compare the forecast point with observed tracks.
Illustrative wind profile for learning. This is not a current or forecast hodograph.
What the low-level segment can reveal
The lowest 500 m and lowest 1 km deserve close attention when surface-based storms and low-level rotation are part of the forecast. Rapid turning or speed change in a shallow layer can create substantial horizontal vorticity near the ground.
Height labels must be accurate. A visually sharp hook that spans the lowest 2 km is not equivalent to the same shape packed into the lowest 500 m. Low-resolution or noisy wind data can also create artificial kinks.
Nearby boundaries can change the segment quickly. Backed surface wind on the cool side of a boundary may enlarge curvature while stable air makes that inflow difficult for a storm to ingest. The wind profile and thermodynamic profile must be read together.
Illustrative wind profile for learning. This is not a current or forecast hodograph.
Straight hodographs still matter
A nearly straight hodograph can support rotating storms when deep-layer shear and instability are suitable. Idealized straight profiles often support storm splitting, with right-moving and left-moving members deviating to opposite sides of the mean wind.
A straight curve may produce less storm-relative helicity for a storm moving near the hodograph, but that one calculation does not erase the dynamic effects of vertical shear. Avoid translating curved into supercell and straight into non-supercell.
Instead, describe the full wind profile, estimate plausible storm motions, and ask how storm-relative flow differs for each mover.
Illustrative wind profile for learning. This is not a current or forecast hodograph.
A practical hodograph scan
First, verify the location, valid time, height labels, and wind units. Compare the surface point with current observations and the low-level profile with nearby radar wind profiles when available.
Second, trace the curve by layer. Describe the lowest 500 m, the lowest 1 km, the lower to middle troposphere, and the deeper storm layer. Note both vector length and directional change.
Third, locate forecast storm motions. Draw the storm-relative vectors mentally or with the product tools. Ask whether inflow is strong, weak, streamwise, or crosswise in the layer the storm may ingest.
Fourth, compare profiles across space and time. Look for boundaries that reshape the low levels, stronger flow approaching aloft, or mixing that changes the surface wind.
Finally, return to the thermodynamic profile. A hodograph can describe the wind environment a storm may encounter. It cannot tell you whether a storm will initiate, remain surface-based, or access the plotted shear.