Deadly tornado in Yancheng, China

June 23rd, 2016

Himawari-8 0.64 µm Visible (top) and 10.4 µm Infrared Window (bottom) images [click to play animation]

Himawari-8 0.64 µm Visible (top) and 10.4 µm Infrared Window (bottom) images [click to play animation]

Himawari-8 AHI Visible (0.64 µm) and Infrared Window (10.4 µm) images (above) showed the east-southeastward propagation of a mesoscale convective system which produced a deadly tornado in Yancheng, China around 2:30 pm local time on 23 June 2016 (Weather Underground blog). The location of Yancheng is denoted by the cyan * symbol, and the animation briefly pauses on the 0630 UTC images which match the reported time of the tornado. Overshooting tops are evident on the visible imagery, and cloud-top infrared brightness temperatures of -80º C or colder (violet color enhancement) also appear, even after the storm crossed the coast and moved over the adjacent offshore waters of the Yellow Sea (note: due to parallax, the apparent location of the storm top features is displaced several miles to the north-northwest of their actual position above the surface). The spatial resolutions (0.5 km visible, 2 km infrared) of the AHI images are identical to those of the corresponding spectral bands that will be available from the ABI instrument on GOES-R.

An experimental version of the MIMIC Total Precipitable Water product which uses the MIRS retrieval TPW from POES, Metop, and Suomi NPP VIIRS satellites (below) revealed the band of high moisture pooled along the Mei-yu front, which appeared to surge northward across eastern China early in the day on 23 June.

MIMIC Total Precipitable Water product [click to play animation]

MIMIC Total Precipitable Water product [click to play animation]

The 23 June/00 UTC rawinsonde report from Nanjing (located about 260 km southwest of Yancheng) indicated a total precipitable water value of 66.2 mm or 2.6 inches (below).

Nanjing, China rawinsonde report [click to enlarge]

Nanjing, China rawinsonde report [click to enlarge]

Mesoscale Convective Vortex (MCV) in Texas

June 12th, 2016

GOES-13 Infrared Window (10.7 µm) images [click to play animation]

GOES-13 Infrared Window (10.7 µm) images [click to play animation]

GOES-13 Infrared Window (10.7 µm) images (above) showed a large Mesoscale Convective System (MCS) that developed in far eastern New Mexico after 2000 UTC on 11 June 2016, then moved eastward and eventually southward over West Texas during the nighttime hours on 12 June. The MCS produced wind gusts to 75 mph and hail of 1.00 inch in diameter in Texas (SPC storm reports).

Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images [click to enlarge]


Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images at 0801 UTC or 3:01 am local time (above) showed cloud-top infrared brightness temperatures were as cold as -83º C (violet color enhancement), along with a number of bright streaks on the Day/Night Band image due to cloud illumination by intense lightning activity (there were around 5000 cloud-to-ground lightning strikes associated with this MCS). On the infrared image, note the presence of cloud-top gravity waves propagating outward away from the core of overshooting tops.

This MCS produced heavy rainfall, with as much as 3.44 inches reported near Lomax (NWS Midland TX rainfall map | PNS). An animation of radar reflectivity (below, courtesy of Brian Curran, NWS Midland) showed the strong convective cells moving southward (before the Midland radar was struck by lightning and temporarily rendered out of service).

Midland, Texas radar reflectivity [click to play MP4 animation]

Midland, Texas radar reflectivity [click to play MP4 animation]

During the subsequent daytime hours, GOES-13 Visible (0.63 µm) images (below) revealed the presence of a large and well-defined Mesoscale Convective Vortex (MCV) as the cirrus canopy from the decaying MCS eroded. A fantastic explanation of this MCV was included in the afternoon forecast discussion from NWS Dallas/Fort Worth. New thunderstorms were seen to develop over North Texas during the late afternoon and early evening hours as the MCV approached — there were isolated reports of hail and damaging winds with this new convection (SPC storm reports). Initiation of this new convection may have also been aided by convergence of the MCV with a convective outflow boundary moving southward from Oklahoma.

GOES-13 Visible (0.63 µm) images [click to play animation]

GOES-13 Visible (0.63 µm) images [click to play animation]

A sequence of Visible images from POES AVHRR (0.86 µm), Terra MODIS (0.65 µm), and Suomi NPP VIIRS (0.64 µm) (below) showed snapshots of the MCV at various times during the day.

Visible images from POES AVHRR (0.86 µm), Terra MODIS (0.65 µm), and Suomi NPP VIIRS (0.64 µm) [click to enlarge]

Visible images from POES AVHRR (0.86 µm), Terra MODIS (0.65 µm), and Suomi NPP VIIRS (0.64 µm) [click to enlarge]

Canada’s first tornado warning of 2016

June 9th, 2016

GOES-13 Visible (0.63 um, top) and Infrared Window (10.7 um, bottom) images [click to play animation]

GOES-13 Visible (0.63 µm, top) and Infrared Window (10.7 µm, bottom) images [click to play animation]

GOES-13 (GOES-East) Visible (0.63 µm) and Infrared Window (10.7 µm) images (above) showed that a cluster of thunderstorms began to develop in far southeastern Saskatchewan around 20 UTC on 09 May 2016, which quickly grew into a large supercell thunderstorm that moved across southwestern Manitoba. This thunderstorm exhibited overshooting tops and a prominent anvil-top plume in the visible images, along with a well-defined “enhanced-V” storm top signature in the Infrared imagery. The minimum cloud-top infrared brightness temperature was -66º C at 2230 UTC.

A higher resolution view was provided by POES AVHRR Visible (0.86 µm) and Infrared (12.0 µm) imagery at 2332 UTC (below) — details of the overshooting top, anvil plume, and enhanced-V signature showed up very well in the 1-km resolution images.

POES AVHRR Visible (0.86 um) and Infrared (12.0 um) images, with surface reports [click to enlarge]

POES AVHRR Visible (0.86 µm) and Infrared (12.0 µm) images, with surface reports [click to enlarge]

Although the storm produced a funnel cloud (prompting the issuance of Canada’s first tornado warning of 2016):



no tornado was confirmed. There were reports of golfball-size hail at Lauder (located just northeast of Melita, Manitoba CWEI) and wind gusts to 96 km/hour or 56 knots at Killarney (located east of Melita).

POES AVHRR CLAVR-x Cloud Top Temperature and Cloud Top Height products (below) indicated minimum values of -76º C and maximum values of 13 km, respectively.

POES AVHRR Cloud Top Temperature and Cloud Top Height products [click to enlarge]

POES AVHRR Cloud Top Temperature and Cloud Top Height products [click to enlarge]

A surface frontal analysis (below) showed that the thunderstorms formed in the broad warm sector of a large occluded low pressure system centered in Saskatchewan, with a secondary low moving eastward across northern  North Dakota — the RTMA surface wind field depicted the broad southerly flow of warm, moist air into Manitoba ahead of the storms (in addition to an interesting area of strong southwesterly flow into the rear flank of the storm).

POES AVHRR Infrared (12.0 µm) image, with surface fronts and RTMA surface winds [click to enlarge]

POES AVHRR Infrared (12.0 µm) image, with surface fronts and RTMA surface winds [click to enlarge]

GOES-14 SRSO-R: severe thunderstorms in parts of the Midwest and the Southern Plains

May 11th, 2016

GOES-14 Infrared Window (10.7 µm) images, with parallax-corrected SPC storm reports [click to play animation]

GOES-14 Infrared Window (10.7 µm) images, with parallax-corrected SPC storm reports [click to play animation]

The GOES-14 satellite remained in Super Rapid Scan Operations for GOES-R (SRSO-R) mode for part of the day on 11 May 2016; Infrared Window (10.7 µm) images (above) showed the nocturnal development of a severe thunderstorm ahead of an approaching occluded front (surface analyses) that dropped large amounts of hail in the northwestern section of Omaha, Nebraska (station identifier KOMA), stripping trees of foliage and clogging some city streets (even requiring the use of snow plows and shovels: photo 1 | photo 2). The storm began to exhibit an “enhanced-V” signature just prior to the time that it started producing large hail in Omaha. Note: the plotted location of the SPC storm reports on this animation (and all animations on this blog post) have been parallax-corrected, moving them slightly north-northeastward to match the location of cloud top features having a mean altitude of 10 km. The letters UNK after a W wind report denotes “unknown intensity”.

During the late afternoon and early evening, GOES-14 Visible (0.63 µm) images (below; also available as a large 59 Mbyte animated GIF) revealed additional thunderstorms which produced hail and damaging winds across eastern Missouri and southern Illinois (SPC storm reports). These storms fired along an outflow boundary left in the wake of another mesoscale convective system (MCS)  that moved through the region earlier in the day.

GOES-14 Visible (0.63 µm) images, with parallax-corrected SPC storm reports [click to play MP4 animation]

GOES-14 Visible (0.63 µm) images, with parallax-corrected SPC storm reports [click to play MP4 animation]

Side note: there was a planned outage of GOES-14 SRSO-R imagery from 1059-2119 UTC. During this time, the GOES-13 (GOES-East) satellite had been placed into Rapid Scan Operations (RSO) mode, providing images as frequently as every 5-7 minutes. Visible (0.63 µm) images (below) showed the mesoscale convective system that produced hail as large as 4.0 inches in diameter in the St. Louis, Missouri area.

GOES-13 visible (0.63 µm) images, with parallax-corrected SPC storm reports [click to play animation]

GOES-13 visible (0.63 µm) images, with parallax-corrected SPC storm reports [click to play animation]

Finally, late in the day another MCS developed in North Texas, just west of the Dallas/Fort Worth area. GOES-14 Visible (0.63 µm) images with parallax-corrected SPC storm reports (below; also available as a large 54 Mbyte animated GIF) showed the large hail and damaging winds produced by this storm. One feature of interest was the “storm-top plume” that emanated from the largest cluster of overshooting tops, and was blown northeastward.

GOES-14 Visible (0.63 µm) images, with parallax-corrected SPC storm reports [click to play MP4 animation]

GOES-14 Visible (0.63 µm) images, with parallax-corrected SPC storm reports [click to play MP4 animation]