Composite Study Examining Five Heavy Snowfall Patterns for South-Central Montana

摘要

This study identifies heavy snow patterns for south-central Montana. Data for theyears 1948-1994 was compiled using the NCEP Version III Grid Point Data Set. Patterns were examined during the time of heaviest snow, and composites made of 5 distinct flow patterns. The five flow patterns composited were: Southwest Flow, Amplified Southwest Flow, West Flow, Northwest Flow, and Closed Low. Conposites were obtained by using the GEMCD program. Fields chosen for the composites were: 500 mb heights, Mean Sea-Level Pressure (MSLP), and 250 mb winds. To isolate the heavier snowfalls, separate composites were performed for single day totals of 5-9 inches. Single day snows of 10+ inches were rare, so they were examined individually.