We use the NCEP/NCAR reanalysis Northern Hemisphere 500mb geopotential heights from 1948-present to create a climatology of weather patterns using a Self Organizing Map method. By utilizing a SOM, we can determine the frequency of each weather pattern through time and flag events where the same weather pattern is repeated over and over and is therefore stagnant. We can also find the length of the 500mb geopotential height contours from the reanalysis data and calculate the sinuosity (length) for each time step that was used to create our SOM. By knowing which days fall into which SOM pattern, we discover the sinuosity of each weather pattern at each location and then determine statistical thresholds to define large amplitude wave patterns that are stagnant. We then explore the precipitation results and impacts from events found within each high amplitude pattern.