Pressure-Wind Triangles of the Pacific Northwest

With inspiration and assistance from Dr. Wolf Read, also known as The Storm King, who utilized pressure-wind triangles in his analysis of historical Pacific Northwest wind storms, I have developed this webpage to study real-time pressure-wind triangles. Using a geostrophic wind calculator developed by Bjarne Hansen in 1988, I have modified the original model and added additional functionality and formulas that incorporate real-time weather station data. This allows for the display of pressure-wind triangles along the West Coast of the United States. The is a beta site that is currently under construction. Additional updates and additions are likely. If you have questions, you can reach me at john@johnrinier.com

The real-time pressure–wind triangles below, updated every 10 minutes and created from a triad of stations, are rotated into a local Cartesian coordinate system to remove spherical-grid curvature, enabling accurate calculation of the geostrophic wind components Ug and Vg from horizontal pressure gradients. Several SQL stored procedures then iterate through these formulas using weather station data gathered from weather observations aggregated by Synoptic Data. With the pressure gradient and bearing derived from each triangle, additional scripts, using the Haversine formula and the Law of Cosines, calculate the respective intersection points. These intersecting points are then grouped and analyzed to identify potential clusters, which help determine the likelihood of a developing low-pressure area. Additional calculations and averaging methods are performed to estimate the approximate pressure reading, derived from a linear interpolation of the nearby triangles’ pressure gradients. The median of the clustered points’ latitudes and longitudes is used to pinpoint the most probable location of the low-pressure center. Once identified, each low-pressure area is drawn on the map with a red circle indicating its approximate central pressure reading along with its corresponding latitude and longitude coordinates. All triangles, intersection points, and identified pressure zones are then plotted dynamically on an interactive graphical map interface, allowing users to click on triangles and markers to view detailed information such as pressure values, wind speeds, and timestamps. Continuous data ingestion and algorithmic updates ensure that the visualization remains accurate, interactive, and reflective of real-time atmospheric changes. Station circles, with links to realtime data, have been added to display wind direction and speed. Stay tuned for more updates!