Bering Sea Superstorm Bottoms out at 924 mb

One of the most powerful extra-tropical storms ever to pass through the Bering Sea reportedly attained a central pressure as low as 924 mb (27.29”) on Friday night/Saturday morning local time. This may rank as the lowest pressure ever ‘analyzed’ (estimated) in the Pacific Basin from an extra-tropical storm system.



Although this may be the lowest pressure ever mapped in the Bering Sea, it is likely that the storm of October 25, 1977 was considerably stronger. An actual measured barometric pressure level (by a ship docked at Dutch Harbor on Unalaska Island in the Aleutians) of 925 mb (29.31”) during that storm would tend to indicate that, at some point, during that storm’s life cycle its central pressure was probably lower than the 925 mb figure measured and thus probably lower than the 924 mb estimate for the current storm.

The most powerful storm, at least in terms of depth of pressure, to affect Alaska in modern history was that of October 25-26, 1977. Dutch Harbor, on the Aleutian Island of Unalaska, recorded a minimum pressure of 925 mb (27.31”) on the evening of October 25th. Winds gusted to 130 mph at Adak, also in the Aleutian Islands. Adak reported a continuous 12-hour period with wind gusts of 110mph+ between 1800Z Oct. 25 and 0600Z Oct. 26. Enhanced infrared radar imagery indicated a closed ‘eye wall’ with this storm. Wave heights of 35 feet on top of swell heights of 60 feet produced significant wave heights of 72 feet according to NWS analysis and ship reports. The analysis speculated that there was the potential for waves as high as 120 feet, although nothing of this magnitude was actually observed. The cyclone had its origins, as is often the case with powerful Alaskan storms, as a West Pacific typhoon.