Sunday, 22 January 2012
Patterns That Produce Large and Small Snowfall Events for Homer, AK
Hall E (New Orleans Convention Center )
The region around Homer, AK receives a varying amount of average yearly snowfall due to orographic and maritime effects. Coupled with above freezing temps at the coast and sub-freezing temps just miles away at higher elevations, snowfall forecasting remains an issue for this region. Snowfall data from the past 10 years was taken from the two COOP sites currently active in the Homer area, and a total of 29 storms were analyzed. Categorizing them into large and small events, small events were defined by 24 hour snowfall amounts of 6-8”, and large events by amounts of ≥10” at either location. The events were further categorized into basic synoptic patterns using the NARR (North American Regional Reanalysis) data by analyzing MSLP and the 500mb height. Further analysis of the storms from the 700mb winds, precipitable water, and instability were performed to gauge how these parameters factored in the intensity of the snowfall events. Output from a high resolution (3Km) WRF model was explored in the modeling of one small event and one large event to determine the main factors differentiating large and small snow events.