Satellite signatures of a meteor in the Bering Sea

December 18th, 2018 |

Himawari-8

Himawari-8 “Red” Visible (0.64 µm) images [click to play animation | MP4]

A meteor entered the Earth’s atmosphere over the Bering Sea (east of Kamchatka) on 18 December 2018. Himawari-8 “Red” Visible (0.64 µm) images (above) showed a bright streak at 23:50 UTC — and a dark-colored debris trail was also evident northwest of this bright streak, which subsequently drifted northeastward.

A warm thermal anomaly was also apparent (at the southern end of the bright streak) on the 2350 UTC Himawari-8 Shortwave Infrared (3.9 µm) image (below).

Himawari-8 "Red" Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images at 2350 UTC [click to enlarge]

Himawari-8 “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images at 2350 UTC [click to enlarge]

GOES-17 was only scanning the Full Disk at 15-minute intervals, so the initial bright meteor streak that was seen with Himawari-8  was not not captured; however, the dark meteor debris cloud drifting northeastward could be followed on Visible imagery (below).

GOES-17 "Red" Visible (0.64 µm) images [click to play MP4 animation | MP4]

GOES-17 “Red” Visible (0.64 µm) images [click to play animation | MP4]

* GOES-17 images shown here are preliminary and non-operational *

Rare December tornado in Washington

December 18th, 2018 |


GOES-17 “Red” Visible (0.64 µm) images, with plots of hourly surface reports and SPC storm reports [click to play animation | MP4]

* GOES-17 images shown here are preliminary and non-operational *

A rare December tornado occurred in Port Orchard, Washington on 18 December 2018. GOES-17 “Red” Visible (0.64 µm) images (above) and “Clean” Infrared Window (10.3 µm) images (below) showed the thunderstorms that moved eastward across the area in the wake of the passage of an occluded front earlier in the day.

GOES-17 "Clean" Infrared Window (10.3 µm) images, with plots of hourly surface reports and SPC storm reports [click to play animation | MP4]

GOES-17 “Clean” Infrared Window (10.3 µm) images, with plots of hourly surface reports and SPC storm reports [click to play animation | MP4]

Due to the relatively large GOES-17 satellite viewing angle (or zenith angle) of 56.38 degrees, there was a modest amount of parallax error in terms of the actual location of cloud-top features associated with the tornado-producing storm. A toggle between GOES-17 Visible and Infrared images at 2147 UTC with SPC tornado reports plotted at their actual and “parallax-corrected” locations (assuming a mean storm-top height of 8 km) are shown below — note how the parallax-corrected tornado plot location more closely aligns with top the parent thunderstorm.

GOES-17 "Red" Visible (0.64 µm) image at 2147 UTC, with SPC tornado report plots at their actual and "parallax-corrected" locations [click to enlarge]

GOES-17 “Red” Visible (0.64 µm) image at 2147 UTC, with SPC tornado report plots at their actual and “parallax-corrected” locations [click to enlarge]

GOES-17 "Clean" Infrared Window (10.3 µm) image at 2147 UTC, with SPC tornado report plots at their actual and "parallax-corrected" locations [click to enlarge]

GOES-17 “Clean” Infrared Window (10.3 µm) image at 2147 UTC, with SPC tornado report plots at their actual and “parallax-corrected” locations [click to enlarge]

A comparison of VIIRS Infrared Window (11.45 µm) images from Suomi NPP (Washington overpass time: 2042 UTC) and NOAA-20 (Washington overpass time: 2132 UTC) is shown below. The coldest cloud-top infrared brightness temperatures on the VIIRS images were -42ºC (bright green enhancement), which corresponded to altitudes of 7-8 km on 00 UTC rawinsonde data from Quillayute, Washington (plot).

VIIRS Infrared Window (11.45 µm) images from Suomi NPP (overpass time 2042 UTC) and NOAA-20 (overpass time 2132 UTC) [click to enlarge]

VIIRS Infrared Window (11.45 µm) images from Suomi NPP (overpass time 2042 UTC) and NOAA-20 (overpass time 2132 UTC), with the location of the SPC tornado report plotted in red [click to enlarge]

A toggle between NOAA-20 VIIRS Infrared Window (11.45 µm) images at the local overpass times of 1952 UTC and 2132 UTC, viewed using RealEarth (below), provided a closer view of the convection.

NOAA-20 VIIRS Infrared Window (11.45 µm) images at 1952 UTC and 2032 UTC [click to enlarge]

NOAA-20 VIIRS Infrared Window (11.45 µm) images at 1952 UTC and 2032 UTC [click to enlarge]

Contrails along the Florida coast

December 18th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, top), Near-Infrared “Cirrus” (1.37 µm, middle) and Low-level Water Vapor (7.3 µm, bottom) images [click to play animation | MP4]

A pair of circular contrails was seen along the coast of the Florida Panhandle in GOES-16 (GOES-East) “Red” Visible (0.64 µm), Near-Infrared “Cirrus” (1.37 µm) and Low-level Water Vapor (7.3 µm) images (above) on 18 December 2018. The contrail features were moving eastward at speed of 50-60 knots.

GOES-16 Water Vapor weighting functions derived using 12 UTC rawinsonde data from Tallahassee, Florida (below) revealed significant contributions by radiation being sensed from levels peaking at either 424 hPa or 442 hPa with all 3 spectral bands — due to a shallow layer of mid-tropospheric moisture — with secondary higher-altitude weighting function peaks around the 300 hPa pressure level.

Water Vapor weighting functions derived using 12 UTC rawinsonde data from Tallahassee, Florida [click to enlarge]

GOES-16 Water Vapor weighting functions derived using 12 UTC rawinsonde data from Tallahassee, Florida [click to enlarge]

Wind speeds from 12 UTC Tallahassee rawinsonde data (below) were 50 knots or greater above the 300 hPa layer, which suggests the contrails existed near that level — and the increased moisture at that high altitude allowed the contrails to persist for nearly 2.5 hours before dissipating.

Plot of 12 UTC rawinsonde data from Tallahassee, Florida [click to enlarge]

Plot of 12 UTC rawinsonde data from Tallahassee, Florida [click to enlarge]

GOES-16 Infrared and Water Vapor winds (source) also showed wind speeds of 50 or greater at higher altitudes in the general vicinity of these contrail features (below).

GOES-16 Infrared and Water Vapor winds [click to play animation]

GOES-16 Infrared and Water Vapor winds [click to play animation]