Nuri transforms into a strong extratropical storm

November 9th, 2014 |
MTSAT-2 6.75 µm IR water vapor channel images (click to play animation)

MTSAT-2 6.75 µm IR water vapor channel images (click to play animation)

Super Typhoon Nuri has completed its transition to one of the strongest extratropical cyclones ever on record in the Bering Sea (Link; Shemya Island had a gust to 96 miles per hour!). The animation above (click here for an mp4, or view it on YouTube) covers the entire lifecycle, from birth out of the ITCZ over the western Pacific to occlusion 7500 km north in the Bering Sea. (A faster animation is available as a animated gif or mp4).

Total Precipitable Water, 0000 6 November 2014 through 0600 9 November 2014 (click to enlarge)

Total Precipitable Water, 0000 6 November 2014 through 0600 9 November 2014 (click to enlarge)

Animations of Total Precipitable Water (from MIMIC) from 6-9 November, above, show that deep tropical moisture associated with Nuri did not make it up into the Bering Sea, but instead was shunted off to the east. Earlier, moisture from Nuri was entrained into the development of a storm in the Bering Sea on 4-5 November. A streamer of high-level moisture in the outflow from Nuri moves northeastward and eastward. That storm subsequently slipped southeastward and made landfall over the Pacific Northwest on 8 November.

Suomi NPP Day Night Band Visible Imagery (0.70 µm) over the Bering Sea, 7-10 November 2014 (click to enlarge)

Suomi NPP Day Night Band Visibe Imagery (0.70 µm) over the Bering Sea, 7-10 November 2014 (click to enlarge)

Suomi NPP overflew the developing storm in the Bering Sea about every twelve hours, and the imagery above, from the GINA Direct Broadcast Antenna at the University of Alaska-Fairbanks, shows the rapid development of a tight swirl of clouds by early on 8 November. Subsequently, the weakening storm drifted northward through the Bering Sea.

GOES-15 also viewed the strong development, both in the window channel (YouTube video) and in the water vapor channel (YouTube video (Color Enhanced)). The visible animation, below, shows a strong cyclone by 0300 UTC on 8 November; at the subsequent sunrise, 2000 UTC, the system had occluded.

GOES-15 0.62 µm IR Visible Imagery on 7, 8 and 9 November 2014 (click to play animation)

GOES-15 0.62 µm IR Visible Imagery on 7, 8 and 9 November 2014 (click to play animation)

Super Typhoon Nuri in the West Pacific Ocean

November 3rd, 2014 |
Advanced Dvorak Technique (ADT) intensity estimate for Super Typhoon Nuri

Advanced Dvorak Technique (ADT) intensity estimate for Super Typhoon Nuri

A plot of the Advanced Dvorak Technique (ADT) intensity estimation for Super Typhoon Nuri (above) shows that the tropical cyclone went through a period of rapid intensification early in the day on 02 November 2014, reaching Super Typhoon strength with sustained winds of 155 knots later in the day.

During this period of rapid intensification, MTSAT-2 10.8 µm IR channel images (below; click image to play animation; also available as an MP4 movie file) showed the development of a small “pinhole” eye (with a diameter of about 15 km); as the storm began to recurve to the north and northeast, a bit of trochoidal motion or “wobble” of the eye was also evident. The coldest cloud-top IR brightness temperatures were -88º C (darker violet color enhancement).

MTSAT-2 10.8 µm IR channel images (click to play animation)

MTSAT-2 10.8 µm IR channel images (click to play animation)

A 375-meter resolution Suomi NPP VIIRS 11.45 µm IR channel image (below; courtesy of William Straka, SSEC) showed great detail in the storm top temperature structure within the eyewall region of Nuri at 17:12 UTC or 2:12 am local time.

Suomi NPP VIIRS 11.45 µm IR channel image

Suomi NPP VIIRS 11.45 µm IR channel image

During the daylight hours,  the COMS-1 satellite provided 15-minute interval 0.675 µm visible channel images (below; click image to play animation; also available as an MP4 movie file) which revealed the presence of mesovortices within the eye of Super Typhoon Nuri.

COMS-1 0.675 µm visible channel images (click to play animation)

COMS-1 0.675 µm visible channel images (click to play animation)

============================= Added 11/04/2014 =====================

Suomi NPP VIIRS 0.7 µm Day Night Band and 11.45 µm Infrared imagery during the overnight hours (16:49 UTC or 1:49 am local time) on 03 November showed a strong, well-organized system. Ample illumination from the Moon in a Waxing Gibbous phase (94% of full) helped to highlight the “visible image at night” capability of the Day/Night Band.

Suomi NPP VIIRS Day Night Band and 11.45 µm Infrared images of the typhoon eye (click to enlarge)

Suomi NPP VIIRS Day Night Band and 11.45 µm Infrared images of the typhoon eye (click to enlarge)

Suomi NPP VIIRS Day Night Band and 11.45 µm Infrared images of the typhoon (click to enlarge)

Suomi NPP VIIRS Day Night Band and 11.45 µm Infrared images of the typhoon (click to enlarge)

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.