Intense hurricane-force storm in the Bering Sea

December 13th, 2015 |

Himawari-8 Water Vapor (6.9 µm) images [click to play animation

Himawari-8 Water Vapor (6.9 µm) images [click to play animation

Japanese Meteorological Agency Himawari-8 Water Vapor (6.9 µm, 2-km resolution) images (above) showed the rapid intensification of a hurricane-force extratropical cyclone over the North Pacific Ocean and Bering Sea during the 12 December – 13 December 2015 period. The 6.9 µm is one of 3 water vapor spectral bands on the Himawari AHI instrument — GOES-R will feature 3 nearly identical water vapor bands on the ABI instrument.

According to surface analyses from the Ocean Prediction Center, the storm was centered over Japan at 00 UTC on 11 December, and began rapidly intensifying later that day as it continued moving northeastward; it eventually deepened to a minimum central pressure of 924 hPa (27.29 inches of mercury) over the far southern Bering Sea at 06 UTC on 13 December. This equaled the analyzed minimum central pressure of Post-Tropical Cyclone Nuri in November 2014, which was one of the strongest storms on record in the Bering Sea.

Corresponding GOES-15 Water Vapor (6.5 µm, 4-km resolution) images (below) offered a slightly closer view of the intensifying storm. The unique satellite signature — resembling a curved scorpion tail — of a phenomenon known as a sting jet was seen to begin developing around 20 UTC on 12 December south of the Aleutian Islands. Several hours after the middle-tropospheric sting jet feature on water vapor imagery moved over Adak Island (PADK on the images) around 0130 UTC, sustained surface winds of 82 knots (94 mph) with gusts to 106 knots (122 mph) were recorded just after 09 UTC. According a Tweet from the Ocean Prediction Center, winds from the storm also produced wave heights of 63 feet.

GOES-15 Water Vapor (6.5 µm) images [click to play animation]

GOES-15 Water Vapor (6.5 µm) images [click to play animation]

A time series of surface observations at Adak Island (below) indicated that the minimum station pressure of 939.0 hPa (27.73 inches of mercury) was recorded just after 04 UTC.

Time series of Adak Island, Alaska surface observation [click to enlarge]

Time series of Adak Island, Alaska surface observation [click to enlarge]

Additional imagery from this event can be found on the RAMMB GOES-R Proving Ground Blog.

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