Tornado-producing severe thunderstorm in northern Italy

July 8th, 2015 |
Metoesat-10 High Resolution Visible (0.8 µm) images (click to play animation)

Metoesat-10 High Resolution Visible (0.8 µm) images (click to play animation)

EUMETSAT Meteosat-10 SEVIRI High Resolution Visible (0.8 µm) images (above; click to play animation) showed the development of an isolated supercell thunderstorm that produced large hail and a violent tornado (1 fatality; estimated EF3 damage) near Venice, Italy (station identifier LIPZ) around 1530 UTC on 08 July 2015. Additional information and imagery is available from meteonetwork.

The corresponding Meteosat-10 Infrared (10.8 µm) images (below; click to play animation) revealed the development of a very cold overshooting top prior to the development of the tornado (1430-1500 UTC) — the minimum cloud-top IR brightness temperature was -70º C (darker black enhancement) on the 1445 UTC image. The overshooting top then rapidly collapsed, as seen by the warming cloud-top IR brightness temperatures on the 1515 and 1530 UTC images. Such an overshooting top collapse sometimes occurs prior to tornado formation in a supercell thunderstorm.

Meteosat-10 Infrared (10.8 µm) images (click to play animation)

Meteosat-10 Infrared (10.8 µm) images (click to play animation)

A close-up view of the 1500 UTC Metosat-10 Infrared (10.8 µm) image is shown below, as displayed using SSEC RealEarth.

Meteosat-10 Infrared (10.8 µm) image, displayed using RealEarth

Meteosat-10 Infrared (10.8 µm) image, displayed using RealEarth

Typhoons Chan-Hom and Nangka in the same Suomi NPP VIIRS Overpass

July 8th, 2015 |
Suomi NPP Day/Night Band (0.70 µm) and Infrared Window Channel (11.45 µm) images at 1616 UTC 8 July 2015 (Click to animate)

Suomi NPP Day/Night Band (0.70 µm) and Infrared Window Channel (11.45 µm) images at 1616 UTC on 8 July 2015 (click to enlarge)

The toggle above shows Suomi NPP VIIRS 0.7 µm Day/Night Band and the 11.45 µm Infrared images (courtesy of William Straka, SSEC). It is unusual because two strong tropical cyclones (Category 2 Typhoon Chan-Hom on the left, and Category 4 Typhoon Nangka on the right) are captured in one satellite overpass.

The Day/Night Band (DNB) image shows little evidence of lightning (bright white streaks) with either storm; due to ample illumination from a Third Quarter Moon (at 54% of Full),  the DNB was able to provide a “visible image at night”. Both images show Nangka to be the stronger storm: the eye is more pronounced, and is more symmetric. More information on these storms is available here.