Wind Vectors

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Corfidi Vectors - The "Corfidi Upshear" vector is an estimate of net storm motion for a "backbuilding" MCS, where the low-level storm inflow is subtracted from the mean wind. The "Corfidi Downshear" vector is an estimate of net storm motion for a "forward propagating" MCS where the low-level storm inflow is added to the mean wind. Please refer to Corfidi, 2003 for more information.

Bunkers Storm Motion Vectors - The "ID method", also known as the "Bunkers" method, was developed by Bunkers et al. (2000) as an estimate of supercell motion. The Bunkers method is gallilean invariant, thus it does not depend on the orientation of the ground-relative winds. The Bunkers motion provides results similar to the "30 degrees right and 75% of the mean wind speed" estimates for typical southwest flow regimes, while the Bunkers motion estimate offers substantial improvments over the 30R75 technique in less common flow regimes (e.g., NW flow or SE flow associated with tropical cyclones). Graphically, the Bunkers storm motion can be estimated by 1) plotting the shear vector from the 0-500 m AGL mean wind to the 5500-6000 m AGL mean wind on a hodograph, 2) plotting the 0-6 km mean wind (pressure weighted), and 3) drawing a vector (of 7.5 m s^-1 magnitude) perpendicular to the shear vector from the 0-6 km mean wind. A perpendicular vector to the right represents the right (cyclonic in northern hemisphere) supercell motion, and a left vector represents the left (anticyclonic in northern hemisphere) supercell motion.