Severe Weather Outbreak Across the Deep South

October 14th, 2014
Suomi NPP 11.35 µm Infrared  Imagery, 1933 UTC 13 October 2014, with Lightning strike data overlain  (click to enlarge)

Suomi NPP 11.35 µm Infrared Imagery, 1933 UTC 13 October 2014, with Lightning strike data overlain (click to enlarge)

An intense extratropical cyclone over the central United States spawned a Quasi-Linear Convective System that moved through the Deep South on 12-13 October 2014; the QLCS was responsible for a spate of severe weather including wind damage, hail and tornadoes (Storm reports from 12 October, 13 October). The image above, from 1933 UTC on 13 October, shows Suomi NPP 11.35 µm imagery over Mississippi. Widespread cold cloud tops are apparent, with embedded overshooting tops. Indeed, the top in southern Hinds County may have been associated with severe Hail. Visible imagery from Suomi NPP (link) also show overshooting tops. The amount of solar reflectance at mid-day, however, makes it difficult to identify all features. The 1.61 µm imagery, below, is darker because ice crystals at cloud top will absorb some energy at that wavelength, yet most features are still recognizable.

Suomi NPP 1.61 µm Near-Infrared  Imagery, 1933 UTC 13 October 2014 (click to enlarge)

Suomi NPP 1.61 µm Near-Infrared Imagery, 1933 UTC 13 October 2014 (click to enlarge)

The GOES-13 Water Vapor Animation, below, is a textbook example of cyclogenesis. Strong sinking in and around the comma head is indicated by the warm water vapor brightness temperatures observed there. This system is also characterized by a very sharp upstream trough and developing warm conveyor belt that turns anticyclonic as it moves over the upper Great Lakes.

GOES-13 Water Vapor 6.7 µm Infrared  Imagery, 1200-2100 UTC 13 October (click to animate)

GOES-13 Water Vapor 6.7 µm Infrared Imagery, 1200-2100 UTC 13 October (click to animate)

GOES-13 10.7 infrared imagery animation, below (also available here as an mp4 file or here as a YouTube video), shows evidence of many overshooting tops in the strong thunderstorms that developed across the deep south. (Indeed, automatic detection of overshooting tops(and cumulative totals from this website) — show some on the 12th, but many more on the 13th) as the extratropical cyclone became organized.

GOES-13 10.7 µm Infrared Imagery, 1600 UTC 13 October - 0700 UTC 14 October 2014 (click to animate)

GOES-13 10.7 µm Infrared Imagery, 1600 UTC 13 October – 0700 UTC 14 October 2014 (click to animate)

The strong system enjoyed a vigorous moisture feed from the Gulf of Mexico, as shown in the MIMIC Total Precipitable Water animation below. Moisture surged northward especially after 1200 UTC on 13 October, and the 24-hour precipitation totals ending at 1200 UTC on 14 October (from this site) showed heavy rain over much of Tennessee and Alabama (and adjacent states).

MIMIC Total Precipitable Water for 72 hours 1200 UTC 14 October 2014 (click to enlarge)

MIMIC Total Precipitable Water for 72 hours 1200 UTC 14 October 2014 (click to enlarge)

GOES Sounder data also shows a quick moistening on 13 October as high Precipitable Water air over the Gulf of Mexico surges northward. Moisture from Pacific Hurricane Simon is unlikely to be a contributing factor to this storm.

GOES Sounder DPI estimates of Total Precipitable Water from through 6 October through October 14 2014 (click to enlarge)

MIMIC Total Precipitable Water for 72 hours 1200 UTC 14 October 2014 (click to enlarge)

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MTSAT-2 and GOES-15 Water Vapor (6.5 µm)Infrared imagery, times as indicated (click to enlarge)

MTSAT-2 and GOES-15 Water Vapor (6.5 µm)Infrared imagery, times as indicated (click to enlarge)

An interesting question arises: Where did some of the energy and moisture for this (somewhat early in the season) storm originate? Water Vapor imagery from MTSAT-2 and GOES-15 show clearly that the Super-Typhoon Phanfone, that was near Japan on 4-5 October, contributed some of the energy to the impulse that moved across the Pacific Ocean and then over the Ridge on the West Coast of North America before diving southeast and forcing cyclogenesis. In the animation above, Phanfone approaches Japan, and is picked up by a mid-latitude jet that crosses the Pacific (tracked by red arrow), induces strong cyclogenesis in the Gulf of Alaska on 8 October and then continues up and over the ridge on the west coast of North America.

Super Typhoon Vongfong in the West Pacific Ocean

October 7th, 2014
Advanced Dvorak Technique plot for Typhoon Vongfong

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)

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

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

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

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 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

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 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

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.

Himawari-8 Launched from Tanegashima Space Center

October 7th, 2014
MTSAT-2 0.73 µm visible channel image at 0514 UTC (click to enlarge)

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).

Typhoon Neoguri threatens Okinawa

July 7th, 2014
COMS-1 0.675 µm and MTSAT-2 0.73 µm Visible channel images (Click to enlarge)

COMS-1 0.675 µm and MTSAT-2 0.73 µm Visible channel images (Click to enlarge)

Typhoon Neoguri is forecast to move west of Okinawa later today. The visible images above, from COMS-1 (left) and MTSAT-2 (right) show the storm at around 0800 UTC on 7 July 2014. A distinct eye filled with low-level clouds is apparent.

COMS-1 (left) and MTSAT-2 (right) visible channel images [click to play animation]

COMS-1 (left) and MTSAT-2 (right) visible channel images [click to play animation]

Magnified views of the storm center (above; click image to play animation; also available as an MP4 movie file) revealed the presence of mesovortices within the eye of Neoguri. The more frequent imaging schedule of COMS-1 (generally every 15 minutes, compared to every 30 minutes with MTSAT-2) allowed the cyclonic circulation of the mesovortices to be more easily identified. Another curious feature seen on the early morning visible imagery was a northwest-to-southeast oriented “cloud cliff” shadow just north of the eye, which was cast by the taller clouds of an eyewall convective burst just to the east. This same signature was seen again on the following morning, in nearly the same location relative to the eye (MTSAT-2 visible/IR image comparison).

METOP-B ASCAT winds over Neoguri and Observed SSTs (Click to toggle)

METOP-B ASCAT winds over Neoguri and Observed SSTs (Click to toggle)

ASCAT winds from METOP-B (above) show the structure of the typhoon, with 70-knot winds indicated. The Sea Surface Temperature (SST) image (taken from the CIMSS Tropical Cyclones site) also shows the extreme warmth of the western Pacific Ocean.

COMS-1 10.8 µm and MTSAT-2 10.8 µm Infrared channel images (Click to animate)

COMS-1 10.8 µm and MTSAT-2 10.8 µm Infrared channel images (Click to animate)

Infrared imagery from the past 24 hours show a decline in the satellite structure of the storm. Cold cloud tops have eroded from the northern and western quadrants of the storm, and a circular ring of cold cloud tops around the eye is no longer apparent.

Suomi NPP VIIRS 11.45 µm  Infrared channel image (Click to enlarge)

Suomi NPP VIIRS 11.45 µm Infrared channel image (Click to enlarge)

Suomi NPP overflew the storm on Saturday 5 July at 1620 UTC. The color-enhanced VIIRS 11.45 IR image, above (courtesy William Straka, SSEC/CIMSS), shows very cold cloud tops (185 K) southeast of a developing eye.