The remnants of Typhoon Hagibis in the Bering Sea

October 14th, 2019 |

GOES-17 Mid-level Water Vapor (6.9 µm) images with surface reports plotted in cyan, then contours of the PV1.5 pressure, followed by the GOES-17 Air Mass RGB [click to play animation | MP4]

GOES-17 Mid-level Water Vapor (6.9 µm) images with surface reports plotted in cyan, then contours of PV1.5 pressure plotted in red, followed by Air Mass RGB images [click to play animation | MP4]

An animation sequence of GOES-17 (GOES-West) Mid-level Water Vapor (6.9 µm) images with surface reports, then contours of PV1.5 pressure, followed by Air Mass Red-Green-Blue (RGB) images (above) showed the remnants of Typhoon Hagibis in the southern Bering Sea on 14 October 2019. During this time period, the extratropical cyclone was analyzed as a Hurricane Force low (surface analyses) —  winds gusted to 62 knots at Adak (PADK) and 60 knots at Shemya (PASY). The PV1.5 surface represents the “dynamic tropopause”, which model fields depicted as  descending as low as the 700 hPa pressure level. Due to the markedly-lower tropopause around and west of the low center, those areas appeared as deeper hues of red/orange on the Air Mass RGB images (influenced by the higher concentrations of ozone-rich stratospheric air within the atmospheric column). The striping seen early in the animation was caused by GOES-17s ABI Loop Heat Pipe issue.

In rawinsonde data from St. Paul Island (PASN), the objectively-decoded tropopause descended from 226 hPa (11 km) at 12 UTC on 14 October to 336 hPa (8.1 km) at 00 UTC on 15 October (below).

Plots of rawinsonde data at St. Paul Island [click to enlarge]

Plots of rawinsonde data at St. Paul Island [click to enlarge]

On the following day, a toggle between Suomi NPP VIIRS Day/Night Band (0.7 µm) images at 2319 UTC on 15 October and 0100 UTC on 16 October (below) showed the remnants of Hagibis briefly making landfall southeast of Anadyr, Russia (UHMA) as a Gale Force low. Winds at Anadyr gusted to 54 knots shortly after the low moved inland.

Suomi NPP VIIRS Day/Night Band (0.7 µm) images at 2319 UTC on 15 October and 0100 UTC on 16 October [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) images at 2319 UTC on 15 October and 0100 UTC on 16 October [click to enlarge]