Smoke plumes from Saudi Arabian oil facilities

September 15th, 2019 |

VIIRS Day/Night Band (0.7 µm) and Visible (0.64 µm) imagery from Suomi NPP and NOAA-20 [click to enlarge]

VIIRS Day/Night Band (0.7 µm) and Visible (0.64 µm) images from Suomi NPP and NOAA-20 (courtesy of William Straka, CIMSS) [click to enlarge]

VIIRS Day/Night Band (0.7 µm) and Visible (0.64 µm) imagery from Suomi NPP and NOAA-20 (above) revealed dark smoke plumes from oil refineries and other facilities damaged by drone strikes early in the day on 14 September 2019.

EUMETSAT Meteosat-8 Visible (0.8 µm) images (below) showed the south-southwestward transport of the smoke plumes. Thick smoke drifted over Al Ahsa (OEAH), and at one point restricted to 2.8 miles.

EUMETSAT Meteosat-8 Visible (0.8 µm) images, with hourly plots of surface reports [click to play animation | MP4]

EUMETSAT Meteosat-8 Visible (0.8 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Before (13 September) and after (14-15 September) True Color Red-Green-Blue (RGB) images from Terra MODIS and Suomi NPP VIIRS as viewed using RealEarth are shown below.

True Color RGB images from Terra MODIS and Suomi NPP VIIRS, from 13-15 September [click to enlarge]

True Color RGB images from Terra MODIS and Suomi NPP VIIRS, from 13-15 September [click to enlarge]

A sequence of 3 VIIRS Day/Night Band images from Suomi NPP and NOAA-20 (below) showed nighttime views of the smoke plumes, illuminated by the Moon (which was in the Waning Gibbous phase, at 98% of Full).

VIIRS Day/Night Band (0.7 µm) from Suomi NPP and NOAA-20 [click to enlarge]

VIIRS Day/Night Band (0.7 µm) from Suomi NPP and NOAA-20 (courtesy of William Straka, CIMSS) [click to enlarge]

A Meteosat-8 Visible animation spanning portions of 14, 15 and 16 September is shown below.

EUMETSAT Meteosat-8 Visible (0.8 µm) images, with hourly plots of surface reports [click to play animation | MP4]

EUMETSAT Meteosat-8 Visible (0.8 µm) images with hourly plots of surface reports, 14-16 September [click to play animation | MP4]

===== 17 September Update =====

Landsat-8 False Color image [click to enlarge]

Landsat-8 False Color RGB image [click to enlarge]

A 30-meter resolution Landsat-8 False Color RGB image (above) showed a number of smoke plumes from oil facility fires that continued to burn on 17 September.

Dorian moves across the Maritime Provinces of Canada

September 8th, 2019 |

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed Hurricane Dorian as it briefly intensified from a Category 1 to a Category 2 storm during the morning of 07 September 2019. Later in the day, Dorian transitioned to a post-tropical storm before making landfall over Nova Scotia around 2215 UTC. Due to high amounts of  deep-layer wind shear, the low-level circulation center of Dorian remained exposed while deep convection remained to its north and northeast. The eye of Dorian moved over Buoy 44011, which recorded a wind gust to 82 knots; in western Nova Scotia, winds gusted to 70 knots at Yarmouth.

VIIRS True Color RGB and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 [click to enlarge]

VIIRS True Color RGB and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 [click to enlarge]

VIIRS True Color RGB and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 as visualized using RealEarth (above) revealed a brighter region exhibiting a somewhat hazy appearance within the cloud-free slot southwest of the eye during the 16-17 UTC period. This could have been a signature of diffuse solar reflection off highly-agitated ocean waves — a NHC discussion noted strong Metop-B ASCAT winds of 80 knots or higher in that area around 15 UTC (below).

Metop-B ASCAT winds [click to enlarge]

Metop-B ASCAT winds [click to enlarge]

On the following day, Suomi NPP VIIRS True Color and Infrared  images (below) showed Post-Tropical Cyclone Dorian when its center was over the Gulf of St. Lawrence. Wind gusts included 68 knots at Heath Point, Quebec (CWHP) and 57 knots at Deer Lake, Newfoundland (CYDF).

Suomi NPP VIIRS True Color RGB and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS True Color RGB and Infrared Window (11.45 µm) images [click to enlarge]


Hurricane Dorian off the coasts of South Carolina and North Carolina

September 5th, 2019 |

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed Hurricane Dorian off the coast of South Carolina from 1116-1900 UTC on 05 September 2019. During this period, Dorian weakened from a Category 3 to a Category 2 hurricane — a plot of deep-layer wind shear from the CIMSS Tropical Cyclones site (below) showed that the storm was moving into an environment of increasingly unfavorable shear.

GOES-16 “Clean” Infrared Window (10.35 µm) images, with contours of deep-layer wind shear at 19 UTC [click to enlarge]

GOES-16 “Clean” Infrared Window (10.35 µm) images, with an overlay of deep-layer wind shear at 19 UTC [click to enlarge]

Dorian’s eye passed directly over EDISTO Buoy 41004; a combined plot of wind speed, wind gust, and air pressure is shown below.  Across the region, peak wind gusts were 98 mph and rainfall was as high as 10.19 inches.

Plot of wind speed (blue), wind gust (red) and air pressure (green) for Buoy 41004

Plot of wind speed (blue), wind gust (red) and air pressure (green) for Buoy 41004

A sequence of VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 as viewed using RealEarth are shown below.

VIIRS True Color RGB and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 [click to enlarge]

VIIRS True Color RGB and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 [click to enlarge]

===== 06 September Update =====

GOES-16 “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

Dorian made landfall on Cape Hatteras, North Carolina around 1235 UTC on 06 September — 1-minute GOES-16 Infrared images (above) showed the eye moving northeastward across the Outer Banks. Peak wind gusts were as high as 110 mph, with rainfall amounts up to 13.74″.

Mesospheric airglow waves over the Northern Plains

September 2nd, 2019 |

VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images from NOAA-20 (0740 UTC) and Suomi NPP (0831 UTC) [click to enlarge]

VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images from NOAA-20 (0740 UTC), Suomi NPP (0831 UTC) and NOAA-20 (0921 UTC) [click to enlarge]

Kudos to Carl Jones (NWS Grand Forks) for spotting this vivid example of mesospheric airglow waves (reference) produced by severe thunderstorms that were responsible for a swath of hail across South Dakota from 0515-1010 UTC on 02 September 2019. In the toggles between VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images from NOAA-20 (at 0740 UTC), Suomi NPP (at 0831 UTC) and NOAA-20 (at 0921 UTC), note that the epicenter of the circular gravity wave patterns appeared to be located west of the convection on the earliest NOAA-20 image and east of the convection in the later NOAA-20 image — this is due to parallax (since the vertically-propagating waves were likely at an altitude near 90 km). This parallax shift was more pronounced in the NOAA-20 images since the high-altitude waves were near the limb of those two satellite swaths. The Moon was in the Waxing Crescent phase (at only 6% of Full), so features seen on the Day/Night Band images were primarily illuminated by airglow.

Closer views centered on the convection are shown below. Cloud-top infrared brightness temperatures in both South Dakota and Nebraska were -70ºC and colder in the NOAA-20 images (which are mislabeled as Suomi NPP), and -80ºC and colder in the Suomi NPP image. Bright white “lightning streak” signatures associated with the thunderstorms were more apparent in these closer views.

 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images from NOAA-20 (0740 UTC), Suomi NPP (0831 UTC) and NOAA-20 (0921 UTC) [click to enlarge]

VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images from NOAA-20 (0740 UTC), Suomi NPP (0831 UTC) and NOAA-20 (0921 UTC) [click to enlarge]

GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images (below) revealed the rapid development of an isolated hail-producing thunderstorm that generated the mesospheric airglow waves.

GOES-16

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC storm reports plotted in cyan [click to play animation | MP4]