Tornadoes in Wyoming

July 28th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with hourly plots of surface observations (cyan/yellow) along with SPC storm reports and Interstate Highways (red) and State Highways (cyan) [click to play MP4 animation]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed the development of a supercell thunderstorm that produced tornadoes, large hail and damaging winds (SPC storm reports) across parts of eastern Wyoming on 28 July 2018. A distinct above-anvil cirrus plume could be seen with this storm.

The corresponding GOES-16 “Clean” Infrared Window (10.3 µm) images (below) revealed that the dominant northern storm began to exhibit a well-defined “enhanced-V” signature (2051 UTC image) about an hour before it began to produce tornadoes. Minimum cloud-top infrared brightness temperatures were in the -60 to -65ºC range (darker shades of red) with the stronger pulses of overshooting tops.

GOES-16 "Clean" Infrared Window (10.3 µm) images, with hourly plots of surface observations (yellow) along with SPC storm reports (cyan) Interstate Highways (violet) and State Highways (cyan) [click to play MP4 animation]

GOES-16 “Clean” Infrared Window (10.3 µm) images, with hourly plots of surface observations (yellow) along with SPC storm reports (cyan) Interstate Highways (violet) and State Highways (cyan) [click to play MP4 animation]

A sequence of Infrared Window images from Suomi VIIRS (11.45 µm) and Aqua MODIS (11.0 µm) (below) showed minimum cloud-top infrared brightness temperatures rapidly cooling from the -40s to -72ºC as the dominant storm crossed Interstate 25.

Suomi NPP VIIRS and Aqua MODIS Infrared Window images [click to enlarge]

Infrared Window images from Suomi NPP VIIRS (11.45 µm) and Aqua MODIS (11.0 µm) [click to enlarge]

A comparison of the Terra and Aqua MODIS Total Precipitable Water product (below) indicated that TPW values increased from the 10-20 mm range to the 20-30 mm range in less than 2 hours.

Terra and Aqua MODIS Total Precipitable Water product [click to enlarge]

Terra and Aqua MODIS Total Precipitable Water product [click to enlarge]

Wildfires in Greece

July 24th, 2018 |

Suomi NPP VIIRS Shortwave Infrared (3.75 µm), Near-Infrared (1.61 and 2.25 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

Suomi NPP VIIRS Shortwave Infrared (3.75 µm), Near-Infrared (1.61 and 2.25 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

Suomi NPP VIIRS Shortwave Infrared (3.75 µm), Near-Infrared (1.61 and 2.25 µm) and Day/Night Band (0.7 µm) images (above) showed thermal signatures and the bright glow of wildfires in the Athens, Greece area at 0005 UTC or 3:05 am local time on 24 July 2018. The 2 largest fires were burning in the vicinity of Kineta and Mati.

Similar images from an overpass of the NOAA-20 satellite 50 minutes later are shown below.

NOAA-20 Shortwave Infrared (3.75 µm), Near-Infrared (1.61 and 2.25 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

NOAA-20 Shortwave Infrared (3.75 µm), Near-Infrared (1.61 and 2.25 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

Over 70 deaths have resulted from these fast-moving wildfires, which were driven by strong winds (below).

Time series of surface observations at Athens, Greece [click to enlarge]

Time series of surface observations at Athens, Greece [click to enlarge]

VIIRS images courtesy of William Straka, CIMSS.

Tornado outbreak in Iowa

July 19th, 2018 |

GOES-16 Upper-level Water Vapor (6.2 µm, top left), Mid-level Water Vapor (6.9 µm, top right), Low-level Water Vapor (7.3 µm, bottom left) and

GOES-16 Upper-level Water Vapor (6.2 µm, top left), Mid-level Water Vapor (6.9 µm, top right), Low-level Water Vapor (7.3 µm, bottom left) and “Red” Visible (0.64 µm, bottom right) images [click to play MP4 animation]

GOES-16 (GOES-East) Upper-level Water Vapor (6.2 µm), Mid-level Water Vapor (6.9 µm), Low-level Water Vapor (7.3 µm) and “Red” Visible (0.64 µm) images (above) revealed the well-defined signature of a mid-tropospheric lobe of vorticity moving from southeastern South Dakota across Iowa during the day on 19 July 2018 — this feature provided synoptic-scale forcing for ascent which aided in the development of severe thunderstorms in central and eastern Iowa. A number of tornadoes were reported, along with some large hail and damaging winds (SPC storm reports).

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with SPC storm reports plotted in red [click to play MP4 animation]

A closer look using 1-minute Mesoscale Domain Sector GOES-16 “Red” Visible (0.64 µm) images (above) showed the line of thunderstorms as they developed in advance of an approaching cold/occluded front (surface analyses). Two larger storms were dominant, which produced tornadoes causing significant damage and injuries in Pella KPEA and Marshalltown KMIWabove-anvil cirrus plumes were evident with both of these supercells. In addition, early in the animation a few orphan anvils could be seen along the southern end of the line (southeast and east of Des Moines KDSM).

The corresponding GOES-16 “Clean” Infrared Window (10.3 µm) images (below) showed cloud-top infrared brightness temperatures of -65ºC to -70ºC with the larger Pella storm, and around -55ºC with the smaller Marshalltown storm to the north.

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with SPC storm reports plotted in red [click to play MP4 animation]

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) image, with ProbSevere contour and parameters [click to enlarge]

The NOAA/CIMSS ProbSevere model (viewed using RealEarth) had a ProbTor value of 74% at 2055 UTC for the Pella storm (above) and 83% at 2130 UTC for the Marshalltown storm (below). GOES-derived Cloud-top glaciation rate (from infrared imagery) is one of the predictors used in the model.

GOES-16 Infrared image, with ProbSevere parameters [click to enlarge]

GOES-16 “Clean” Infrared Window (10.3 µm) image, with ProbSevere contour and parameters [click to enlarge]

ProbSevere time series plots for the Pella and Marshalltown cells are shown below. They indicated that the Pella storm was long-lived, persisting past 0300 UTC — and that ProbTor ramped up quickly and then down quickly, bracketing the time of the tornado in Marshalltown.

NOAA/CIMSS ProbHail (Green), ProbWind (Blue) and ProbTor (Red) for the cell that produced the Pella IA tornado. [click to enlarge]

NOAA/CIMSS ProbHail (Green), ProbWind (Blue) and ProbTor (Red) for the cell that produced the Pella IA tornado [click to enlarge]

NOAA/CIMSS ProbHail (Green), ProbWind (Blue) and ProbTor (Red) for the cell that produced the Marshalltown IA tornado [click to enlarge]

A toggle between 375-meter resolution Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images at 1946 UTC (below) provided a look at the early stage of development of tornado-producing convection.

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images, with plots of SPC tornado reports within +/- 30 minutes of the images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images, with plots of SPC tornado reports within +/- 30 minutes of the images [click to enlarge]

Additional satellite imagery and analysis of this event can be found on the Satellite Liaison Blog.


Occluded cyclone in southern Canada

July 15th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, upper left), Low-level Water Vapor (7.3 µm, upper right), Mid-level Water Vapor (6.9 µm, lower left) and Upper-level Water Vapor (6.2 µm, lower right) images [click to play animation]

A 4-panel comparison of GOES-16 (GOES-East) “Red” Visible (0.64 µm), Low-level Water Vapor (7.3 µm), Mid-level Water Vapor (6.9 µm) and Upper-level Water Vapor (6.2 µm) images (above) showed a large occluded cyclone (surface analyses) over northern Saskatchewan and northern Manitoba on 15 July 2018. In the cold sector of the storm, morning temperatures were confined to the 40s F — especially at Churchill, Manitoba where strong easterly winds were blowing off Hudson Bay.

A closer examination of the GOES-16 images (below) revealed the presence of waves over southwestern Manitoba on the Water Vapor imagery — these appeared to vertically-propagating waves which formed due to the interaction of strong boundary layer winds with the topography of that area (some land features rise to 2600 feet). These waves then began breaking and propagating slowly westward late in the animation.

GOES-16 "Red" Visible (0.64 µm, upper left), Low-level Water Vapor (7.3 µm, upper right), Mid-level Water Vapor (6.9 µm, lower left) and Upper-level Water Vapor (6.2 µm, lower right) images [click to play animation]

GOES-16 “Red” Visible (0.64 µm, upper left), Low-level Water Vapor (7.3 µm, upper right), Mid-level Water Vapor (6.9 µm, lower left) and Upper-level Water Vapor (6.2 µm, lower right) images [click to play animation]

A NOAA-20 VIIRS True Color Red-Green-Blue (RGB) image (below) showed numerous smoke plumes from wildfires in southeastern Manitoba and western Ontario, as well as the light cyan color of ice in central and eastern portion of Hudson Bay (ice analysis: northern | southern).

NOAA-20 VIIRS True Color RGB image [click to enlarge]

NOAA-20 VIIRS True Color RGB image [click to enlarge]