Advanced Dvorak Technique plot for Typhoon Vongfong

Beginning shortly before 00 UTC on 07 October 2014, Typhoon Vongfong began a period of rapid intensification, as shown on a plot of the Advanced Dvorak Technique (ADT) intensity estimate (above). The peak ADT intensity late in the day was 146 knots. On the other hand, the CIMSS Satellite Consensus or SATCON indicated a peak intensity of 156 knots around that time.

MTSAT-2 10.8 µm IR channel images beginning during the period of rapid intensification on 07 October and extending into 08 October (below; click image to play animation; also available as an MP4 animation) revealed the formation of a very large and well-defined eye. There were large portions of the eyewall which exhibited cloud-top IR brightness temperatures of -80º C and colder (purple color enhancement).

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

A large-scale view and a close-up view of the eye of Vongfong using Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm IR channel images at 16:59 UTC or 1:59 am local time are shown below (courtesy of William Straka, SSEC). Due to an abundance of reflected light from a Full Moon, these examples demonstrate the “visible image at night” capability of the VIIRS Day/Night Band.

Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm IR channel images

Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm IR channel images

In a comparison of a MTSAT-2 10.8 µm IR image with the corresponding DMSP SSMIS 85 GHz microwave image around 22:47 UTC (below), there was evidence of the formation of a larger secondary eyewall surrounding the primary eyewall (which can signal the beginning of an eyewall replacement cycle). Using the microwave data, the diameter of the eye was determined to be 60.59 km.

MTSAT-2 10.8 um IR image and DMSP SSMIS 85 GHz microwave image

As the morning sun began to illuminate Super Typhoon Vongfong around 21:32 UTC, an MTSAT-2 0.675 µm visible channel image (below) provided a stunning view of the eye of the intense tropical cyclone. An animation of subsequent MTSAT-2 visible images revealed the presence of mesovortices within the eye.

MTSAT-2 0.675 µm visible channel image

08 October Update: A large-scale view and a close-up view of the eye of Super Typhoon Vongfong using Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm IR channel images at 16:40 UTC or 1:40 am local time on 08 October are shown below (courtesy of William Straka, SSEC).

Suomi NPP VIIRS 0.7 µm Daqy/Night Band and 11.45 µm IR channel images

Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm IR channel images

11 October Update: A large-scale view and a close-up view of the eye of a weakened Vongfong (as it passed near the island of Okinawa) using Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm IR channel images at 17:18 UTC on 11 October are shown below (courtesy of William Straka, SSEC).

Suomi NPP VIIRS 0.7 µm Daqy/Night Band and 11.45 µm IR channel images

Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm IR channel images

Additional satellite images of Super Typhoon Vongfong can be found on the Satellite Liaison Blog.

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GOES-15 10.7 µm infrared channel imagery in Sitka Sector (click to enlarge)

NOAA/NESDIS placed GOES-15 in Rapid Scan Operations (RSO) mode for several hours on 7 October 2014 (link) to test RSO capabilities over different sectors of the Pacific Ocean. RSO Capabilities over the Pacific were possible in the 1990s; the testing yesterday showed they could be done again. Three sectors were scanned. The Sitka sector, above (centered near the Island of Sitka), can monitor the eastern Gulf of Alaska and western North America. The other sectors were over Hawaii (below, the Hawaii Sector) and over the western Gulf of Alaska and parts of the Bering Sea (bottom, the TPARC Sector, which sector overlaps a THORPEX experiment site).

GOES-15 10.7 µm infrared channel imagery in Hawaii Sector (click to enlarge)

GOES-15 10.7 µm infrared channel imagery in TPARC Sector (click to enlarge)

NESDIS is investigating why these RSO data did not flow into AWIPS as intended.

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Update, 15 October 2014.

A second RSO Test occurred on 15 October (Link). Data from this successful RSO test were available in AWIPS during this test. GOES-15 scanning strategies are shown here. The Hawaii sector is shown here. Data available over the Hawaii sector from 1930 to 2030 UTC on 15 October are shown below.

GOES-15 10.7 µm infrared channel imagery in Hawaii Sector (click to animate)

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MTSAT-2 0.73 µm visible channel image at 0514 UTC (click to enlarge)

The Japanese Satellite Himawari-8 was successfully launched from
southern Tanegashima Island today at 05:16 UTC. (NASA News Source). Is the plume from that launch visible in MTSAT imagery? The visible imagery with a nominal time of 0514 UTC was actually scanning Tanegashima Island at 0519 UTC, and a plume, denoted by the yellow arrow above, is visible off the southern edge of the Island. (The 0501 UTC image of the same scene, pre-launch, is here).

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Suomi NPP VIIRS Day/Night Band (0.70 µm), Infrared Imagery (11.45 µm) and Day/Night Band imagery with lightning strikes at 0842 UTC on 6 October 2014 (click to animate)

The Suomi NPP VIIRS image toggle, above, from the pre-dawn hours (3:42 am local time) on 6 October 2014 shows a 0.7 µm Day/Night Band image and an 11.45 µm Infrared image, along with observations of postive and negative lightning strikes. With ample illumination by moonlight, the “visible image at night” Day/Night Band image highlighted areas of convective overshooting tops, but also included bright horizontal stripes that are associated with intense lightning activity; after scanning a particularly bright area of lightning in Arkansas, this image also showed a darker “post-saturation recovery” stripe downscan (to the southeast), which stretched from central Arkansas into Mississippi. This vigorous convective system dropped southeastward from Oklahoma towards the Gulf of Mexico, eventually becoming a Quasi-Linear Convective System (QLCS) which produced hail and wind damage (with one fatality) across parts of northeastern Texas and far northwestern Louisiana (SPC storm reports).

GOES Sounder DPI Lifted Index (click to animate)

The southward-dropping Mesoscale Convective System followed a channel of unstable air as diagnosed by the GOES Sounder, above. Note that the Lifted Index values were smaller (less instability) along the path that the system had moved. Total Precipitable water was also enhanced in that corridor, suggesting a region where moisture return from the Gulf of Mexico was ongoing and concentrated.

GOES Infrared Imagery (10.7 µm) at 1600 UTC, and Pilot Reports of Turbulence (click to enlarge)

Mesoscale Convective Systems can exhibit signatures that suggest the presence of turbulence in the atmosphere. In the GOES-13 IR image above, parallel filaments or “transverse bands” of cirrus  (extending approximately north-south) on the poleward side of the MCS suggest the presence of turbulence, and scattered pilot reports of Moderate Turbulence confirm that. Visible MODIS Imagery, below, also shows the transverse bands, as well as the outflow boundary arcing from Houston to the northwest and north.

Terra MODIS visible imagery (0.65 µm) at 1705 UTC (click to enlarge)

An animation of hourly GOES-13 Visible imagery, below, shows the motion of the western portion of the outflow boundary as the decaying QLCS moved into the Gulf of Mexico.

GOES-13 Visible (0.65µm) imagery (click to animate)

GOES-13 6.5 µm water vapor channel imagery, below, displayed a signature of subsidence immediately upstream of the dissipating MCS, in the form of an arc of warmer/drier (yellow to orange color enhancement) brightness temperatures that extended from the Texas coast into central Arkansas. One rapidly-developing convective cell which formed along the advancing outflow boundary was responsible for severe turbulence in eastern Texas; the subtle signal of the westward-propagating outflow boundary could also be followed on the water vapor imagery.

GOES-13 6.5 µm water vapor channel images, with pilot reports of turbulence (click to play animation)

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