83rd Annual

Sunday, 9 February 2003
Predicting High-wind Events Impacting Barrow, Alaska through Ananlysis of Regional Sea-Level Pressure Patterns
Casey C. Thornbrugh, UCAR, College Park, MD

Barrow, Alaska is a coastal community that is vulnerable to coastal flooding and structural damage from local high-wind events during the “ice-free” season from the late summer through autumn. Historically, high latitude Arctic cyclonic storms have not occurred frequently in Barrow, however, with the current warming trend in the Arctic, these storms, which generate high-winds, may become more intense. This project intended to identify regional sea-level pressure (SLP) patterns associated with high-wind events in Barrow. This was done with the use of the Self Organizing Map (SOM) algorithm, which identifies frequently occurring spatial patterns within a large data set. The region of interest encompasses Alaska, eastern Siberia, the Chukchi Sea, the Bering Sea, and the Beaufort Sea. The 12-hourly SLP input data was obtained from the NCEP/NCAR Reanalysis for the period: August 1 to November 30 from 1948 to 2001. This data was run through the SOM software, which was configured to identify 48 distinct SLP patterns. The 48 SLP output patterns were compared to actual SLP patterns from 14 major high-wind events in Barrow from 1950 to 2000. Seventy-two percent of the 12-hourly SLP patterns from the 14 storms were similar to a pattern from the array of 48 SLP output patterns. With the identification of specific types of SLP patterns that have the potential to generate winds and coastal flooding destructive to Barrow, local weather forecasters can relay the information to Barrow residents giving the community enough time to prepare for these high-wind events.

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