Aeroflot 270 encounters severe turbulence approaching Thailand

May 1st, 2017 |

Himawari-8 Water Vapor (6.9 µm) images, with plots of turbulence intensity along the flight path [click to enlarge]

Himawari-8 Water Vapor (6.9 µm) images, with plots of turbulence intensity along the flight path [click to enlarge]

Aeroflot Flight 270 encountered severe turbulence just off the coast of Myanmar (CNN | Aviation Herald) as it was flying toward its destination of Bangkok, Thailand on 01 May 2017. According to information from FlightRadar24 (flight map) and FlightAware (flight map | flight log) the time and location of the turbulence was around 23:54-23:56 UTC, near 16.4 N latitude, 97.4 East longitude, at the cruising altitude of 35,000 feet. Himawari-8 Water Vapor (6.9m) images (above; courtesy of Sarah Griffin, CIMSS) indicated that the aircraft made a slight course correction to fly over or through a small cluster of rapidly-developing thunderstorms — this convection was the likely cause of the turbulence.

Closer views of Himawari-8 Visible (0.64 µm), Water Vapor (6.9 µm) and Infrared Window (10.4 µm) images, centered at the location of the turbulence encounter (below), showed the rapid development of individual convective elements within this cluster of thunderstorms. Cloud-top infrared brightness temperatures were around -70º C on the 01 May / 00:10 UTC image.

Himawari-8 Visible (0.64 µm, top), Water Vapor (6.9 µm, middle) and Infrared Window (10.4 µm, bottom) images [click to enlarge]

Himawari-8 Visible (0.64 µm, top), Water Vapor (6.9 µm, middle) and Infrared Window (10.4 µm, bottom) images [click to enlarge]

Mountain waves over the Sierra Nevada

April 13th, 2017 |

GOES-16 7.3 µm (left), 6.9 µm (center) and 6.2 µm (right) Water Vapor images [click to play animation]

GOES-16 7.3 µm (left), 6.9 µm (center) and 6.2 µm (right) Water Vapor images [click to play animation]

 ** The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. **

A comparison of GOES-16 Lower-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (above) revealed the presence of numerous mountain waves over parts of California and Nevada on 13 April 2017. The more pronounced of these waves were caused by strong southwesterly winds interacting with  higher terrain of the Sierra Nevada.

A 3-satellite comparison of GOES-15 (GOES-West), GOES-16 and GOES-13 (GOES-East) Water Vapor images (below) highlighted 2 factors that allowed better detection of these mountain waves by GOES-16 — improved spatial resolution (2 km for GOES-16 at satellite sub-point, vs 4 km for GOES-15/13), and a more direct satellite viewing angle (GOES-16 is positioned at 105ºW longitude, while GOES-15 is at 135ºW and GOES-13 is at 75ºW).

OES-15 (6.5 µm, left), GOES-16 (6.9 µm, center) and GOES-13 (6.5 µm, right) Water Vapor images [click to play animation]

GOES-15 (6.5 µm, left), GOES-16 (6.9 µm, center) and GOES-13 (6.5 µm, right) Water Vapor images [click to play animation]

Note that there were no Visible cloud features associated with many of the waves seen on Water Vapor imagery (below); encounters of Clear Air Turbulence (CAT) often occur with these types of mountain waves, as seen by scattered pilot reports of moderate turbulence (plotted as Category 4).

GOES-16 Visible (0.64 µm, left) and Water Vapor (6.9 µm, right) images, with pilot reports of turbulence [click to play animation]

GOES-16 Visible (0.64 µm, left) and Water Vapor (6.9 µm, right) images, with pilot reports of turbulence [click to play animation]

Eruption of Kambalny volcano in Kamchatka, Russia

March 25th, 2017 |

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

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

The Kambalny volcano in far southern Kamchatka, Russia erupted around 2120 UTC on 24 March 2017. A Himawari-8 “Target Sector” was positioned over that region — providing rapid-scan (2.5-minute interval) imagery — as seen in a 2-panel comparison of AHI Visible (0.64 µm) and Infrared Window (10.4 µm) data covering the first 7 hours of the eruption (above). Ash plume infrared brightness temperatures quickly became -40ºC and colder (bright green enhancement).

Himarari-8 false-color RGB images [click to play animation]

Himarari-8 false-color RGB images [Click to play animation]

Himawari-8 false-color Red/Green/Blue (RGB) images from the NOAA/CIMSS Volcanic Cloud Monitoring site (above) showed the ash plume drifting south-southwestward during the subsequent nighttime hours. It is interesting to note the formation and subsequent northwestward motion of numerous contrails (darker green linear features) across the region, due to the close proximity of a major Tokyo flight corridor.

True-color RGB images from Terra MODIS, Suomi NPP VIIRS and Aqua MODIS, viewed using RealEarth (below) revealed the long ash plume during the late morning and early afternoon on 25 March. The dark signature of ash fall onto the snow-covered terrain was evident on the Terra and Aqua images, just west of the high-altitude ash plume.

Terra MODIS, Suomi NPP VIIRS and Aqua MODIS true-color RGB images [Click to enlarge]

Terra MODIS, Suomi NPP VIIRS and Aqua MODIS true-color RGB images [Click to enlarge]

26 March Update: a closer view of Terra MODIS true-color images from 25 and 26 March (below) showed that the perimeter of the darker gray surface ash fall signature had fanned out in both the west and east directions.

Terra MODIS truecolor RGB images from 25 and 26 March, with arrows indicating the perimeter of surface ash fall signatures on each day [Click to enlarge]

Terra MODIS truecolor RGB images from 25 and 26 March, with arrows indicating the perimeter of surface ash fall signatures on each day [Click to enlarge]

Winter storm from the Upper Midwest to the Northeast US

March 15th, 2017 |

GOES-16 Water Vapor (6.9 µm) images, with hourly plots of surface weather [click to play MP4 animation]

GOES-16 Water Vapor (6.9 µm) images, with hourly plots of surface weather [click to play MP4 animation]

** The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. **

A winter storm produced heavy snow across parts of the Upper Midwest on 13 March 2017, and then merged with subtropical jet stream energy to help develop an intense and rapidly-deepening storm which affected much of the Northeast US during 14 March15 March (WPC storm summary). GOES-16 ABI Water Vapor (6.9 µm) images covering the 13-15 March period (above) showed the development and motion of this complex storm. .

A closer view of the Northeast US on 14 March (below) displayed some of the complex banding structures associated with the deepening storm, and also showed the sharp gradient of precipitation type along the coastal areas. Notable weather impacts included a storm total snowfall of 48.4 inches at Hartwick, New York, a new all-time 24-hour snowfall accumulation of 31.1 inches at Binghamton, New York, 0.4 inch of freezing rain accumulation at Chesilhurst, New Jersey and a wind gust of 77 mph at Plum Island, Massachusetts.

GOES-16 Water Vapor (6.9 um) images, with hourly surface weather symbols [click to play animation]

GOES-16 Water Vapor (6.9 um) images, with hourly surface weather symbols [click to play animation]

Some interesting features were also seen in the wake of the large Northeast US component of the storm. For example, a GOES-16 Mesoscale Sector provided 1-minute interval  0.5-km resolution Visible (0.64 µm) imagery of lake effect snow bands streaming southward off Lake Michigan on 14 March, which produced heavy snow in parts of southeastern Wisconsin, northeastern Illinois and northwestern Indiana (below).

GOES-16 Visible (0.64 µm) images, with hourly surface plots [click to play MP4 animation]

GOES-16 Visible (0.64 µm) images, with hourly surface plots [click to play MP4 animation]

GOES-16 6.2 µm, 6.9 µm and 7.3 µm Water Vapor images (below) revealed widespread mountain waves downwind of the southern Appalachians on 15 March.

GOES-16 Water Vapor images: 6.2 µm (top), 6.9 µm (middle) and 7.3 µm (bottom) [click to play animation]

GOES-16 Water Vapor images: 6.2 µm (top), 6.9 µm (middle) and 7.3 µm (bottom) [click to play animation]

These mountain waves were responsible for a few pilot reports of moderate turbulence, two of which are highlighted below.

GOES-13 Water Vapor (6.5 µm) image, with pilot report of turbulence [click to enlarge

GOES-13 Water Vapor (6.5 µm) image, with pilot report of turbulence [click to enlarge]

GOES-13 Water Vapor (6.5 µm) image, with pilot report of turbulence [click to enlarge]

GOES-13 Water Vapor (6.5 µm) image, with pilot report of turbulence [click to enlarge]