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 Barbara in the East Pacific

July 2nd, 2019 |

GOES-17

GOES-17 “Red” Visible (0.64 µm, top) and “Clean” Infrared Window (10.3 µm, bottom) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (above) showed the eye of Category 4 Hurricane Barbara on 02 July 2019. Mesovortices were briefly seen within the eye in the Visible imagery. Barbara was moving through an environment of low deep-layer wind shear and over warm water, factors favorable for rapid intensification (ADT | SATCON).

DMSP-17 SSMIS Microwave (85 GHz) imagery from the CIMSS Tropical Cyclones site (below) showed a closed eyewall at 1448 UTC.

DMSP-17 SSMIS Microwave (85 GHz) image [click to enlarge]

DMSP-17 SSMIS Microwave (85 GHz) image [click to enlarge]

A 1700 UTC  GOES-17 “Red” Visible image with an overlay of Metop-A ASCAT winds (below) revealed surface scatterometer wind speeds as high as 76 knots just north of the eye.

GOES-17

GOES-17 “Red” Visible (0.64 µm) and Metop-A ASCAT winds [click to enlarge]

===== 03 July Update =====

GOES-17 "Red" Visible (0.64 µm, top) and "Clean" Infrared Window (10.3 µm, bottom) images [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm, top) and “Clean” Infrared Window (10.3 µm, bottom) images [click to play animation | MP4]

Barbara maintained Category 4 intensity on 03 July — and 1-minute GOES-17 Visible and Infrared GOES-17 images (above) provided a better view of mesovortices within the eye.

Cyclone Kenneth makes landfall in Mozambique

April 25th, 2019 |

Meteosat-8 Visible (0.8 µm) images [click to play animation | MP4]

Meteosat-8 Visible (0.8 µm) images [click to play animation | MP4]

EUMETSAT Meteosat-8 Visible (0.8 µm) images (above) and Infrared Window (10.8 µm) images (below) showed Category 4 Cyclone Kenneth (12 UTC JTWC advisory) making landfall along the northeast coast of Mozambique (north of Pemba FQPB: surface observations) on 25 April 2019. Kenneth had been moving over warm water and through an environment of low deep-layer wind shear, factors favorable for its rapid intensification (ADT | SATCON). After making landfall, Kenneth rapidly weakened to Category 1 intensity by 18 UTC — but Metop-A ASCAT winds of 40-49 knots were still sampled along the coast on the rear periphery of the storm. The slow inland movement of the remnants of Kenneth combined with copious amounts of tropical moisture as depicted by MIMIC TPW posed a concern for potential flooding problems.

Meteosat-8 Infrared Window (10.8 µm) images [click to play animation | MP4]

Meteosat-8 Infrared Window (10.8 µm) images [click to play animation | MP4]

VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20, viewed using RealEarth (below), provided higher-resolution views of Kenneth a few hours prior to landfall. This was the strongest tropical cyclone landfall on record for the northern portion of Mozambique, as discussed here.

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]

GCOM-W1 AMSR2 Microwave (89 GHz) image (below, courtesy of William Straka, CIMSS) showed the eye and spiral band structures near the Mozambique coast at 1030 UTC on 25 April. The evolution of the eye since its initial formation on 23 April was evident in the MIMIC TC product.

GCOM-W1 AMSR2 Microwave (89 GHz) image [click to enlarge]

GCOM-W1 AMSR2 Microwave (89 GHz) image [click to enlarge]

A longer animation of Meteosat-8 Infrared images (below) during the later half of its storm track showed the formation of an eye as Kenneth began its period of rapid intensification on 24 April. Cloud-top infrared brightness temperatures were -90ºC and colder (yellow pixels embedded with darker shades of purple) during the 1030-1800 UTC period on 24 April. Note that the center of Kenneth passed just north of the island of Grande Comore soon after the eye had developed — at Prince Said Ibrahim International Airport FMCH in Moroni, southeast winds gusted to 65 knots at 21 UTC 0n 24 April as the southern eyewall passed over the island.

Meteosat-8 Infrared Window (10.8 µm) images [click to play animation | MP4]

Meteosat-8 Infrared Window (10.8 µm) images [click to play animation | MP4]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images (below, courtesy of William Straka, CIMSS) showed Kenneth at 2232 UTC on 24 April, shortly before the tropical cyclone had reached Category 4 intensity. Ample illumination from the Moon — in the Waning Gibbous phase, at 73% of Full — provided an excellent example of the “visible image at night” capability of the VIIRS Day/Night Band.

NOAA-20 Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Satellite signatures of the Notre Dame Cathedral fire in Paris, France

April 15th, 2019 |

EUMETSAT Meteosat-11 Shortwave Infrared (3.92 µm) images, with airport identifiers plotted in red [click to play animation | MP4]

EUMETSAT Meteosat-11 Shortwave Infrared (3.92 µm) images, with airport identifiers plotted in red [click to play animation | MP4]

The subtle thermal anomaly (or “hot spot”) from the Notre Dame Cathedral Fire was evident in 4.8-km resolution (at satellite nadir) EUMETSAT Meteosat-11 Shortwave Infrared (3.92 µm) imagery (above) as a cluster of brighter yellow pixels just north of Paris Orly International Airport (LFPO) near the center of the images on 15 April 2019.

The fire reportedly began around 1650 UTC; the maximum 3.92 µm brightness temperature sensed by Meteosat-11 was 284.5 K (11.35ºC) on the 1745 UTC image, not long after the fire had spread to the large spire of the cathedral (Meteosat-11 was actually scanning the Paris area at 1756 UTC, since the Meteosat Second Generation satellites scan each Full Disk from south to north). Clouds approaching from the west began to mask the fire signature at 1930 UTC.

Even though high clouds had begun to move overhead, a thermal signature (darker black pixel) could still be seen in 1-km resolution Metop-A and Metop-C Shortwave Infrared (3.75 µm) images at 2009 and 2048 UTC (below, courtesy of William Straka, CIMSS). The maximum 3.75 µm brightness temperature detected by Metop was 291.1 K (18.0ºC).

Metop-A and Metop-C Shortwave Infrared (3.74 µm) images at 2009 and 2048 UTC [click to enlarge]

Metop-A and Metop-C Shortwave Infrared (3.75 µm) images at 2009 and 2048 UTC [click to enlarge]