Super Typhoon Goni in the West Pacific Ocean

October 30th, 2020 |

JMA Himawari-8

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

2.5-minute rapid scan JMA Himawari-8 “Red” Visible (0.64 µm) images (above) showed Category 5 Super Typhoon Goni in the West Pacific Ocean on 30 October 2020. The images revealed a very small “pinhole eye”, surface mesovortices within the eye and a trochoidal motion — all characteristics of a tropical cyclone at/near its peak intensity (Goni had a satellite-derived estimate of 160 knots at 00 UTC). The trochoidal “wobble” was more evident in a faster animation.

The corresponding Infrared (10.4 µm) images (below) revealed cloud-top infrared brightness temperatures that were frequently in the -80 to -85ºC range (shades of violet).

JMA Himawari-8 "Clean" Infrared Window (10.4 µm) images [click to play animation | MP4]

JMA Himawari-8 “Clean” Infrared Window (10.4 µm) images [click to play animation | MP4]

Longwave Infrared (11.2 µm) images with contours of 00 UTC deep-layer wind shear from the CIMSS Tropical Cyclones site (above) indicated Goni was in an environment of very low shear at that time.

Himawari-8 Longwave Infrared (11.2 µm) images, with contours of 0i0 UTC deep-layer wind shear [click to enlarge]

Himawari-8 Longwave Infrared (11.2 µm) images, with contours of 00 UTC deep-layer wind shear [click to enlarge]

===== 31 October Update =====

JMA Himawari-8 "Clean" Infrared Window (10.4 µm) images [click to play animation | MP4]

JMA Himawari-8 “Clean” Infrared Window (10.4 µm) images [click to play animation | MP4]

Super Typhoon Goni maintained Category 5 intensity for over 24 hours, and actually intensified to 170 knots (JTWC advisory | ADT | SATCON) at 18 UTC on 31 October, just prior to making landfall along Catanduanes Island in the Philippines around 2050 UTC (a closer view of landfall using RealEarth is available here). At 170 knots, Goni became one of the most intense landfalling tropical cyclones on record.

Note the rapid deterioration of the eye upon landfall — this was likely due to a combination of interaction with the terrain of the island, and increasing deep-layer wind shear (below). As it was approaching the Philippines, Goni had been moving over very warm water characterized by high values of Sea Surface Temperature and Ocean Heat Content.

Himawari-8 Water Vapor images, with contours of deep-layer wind shear [click to enlarge]

Himawari-8 Water Vapor images, with contours of deep-layer wind shear [click to enlarge]

A DMSP-16 SSMIS Microwave (85 GHz) image at 2032 UTC is shown below.

DMSP-16 SSMIS Microwave image at 2032 UTC [click to enlarge]

DMSP-16 SSMIS Microwave (85 GHz) image at 2032 UTC [click to enlarge]

 A NOAA-20 VIIRS Infrared Window (11.45 µm) image (below) showed Goni just after 16 UTC.

NOAA-20 VIIRS Infrared Window (11.45 ) image [click to enlarge]

NOAA-20 VIIRS Infrared Window (11.45 µm) image [click to enlarge]

Hurricane Teddy and wildfire smoke

September 22nd, 2020 |

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 (GOES-East) True Color Red-Green-Blue (RGB) images created using Geo2Grid (above) revealed that the large circulation of Hurricane Teddy (downgraded from a Category 2 to a Category 1 storm at 18 UTC) was drawing hazy filaments of smoke — likely originating from wildfires in the western US — southward from eastern Canada and New England, carrying it across the far western Atlantic Ocean on 22 September 2020. Also of interest (early in the animation) were the narrow fingers of river valley fog across parts of New York, Pennsylvania, Maryland, West Virginia and Virginia.

Although the size of Teddy’s cloud shield was still fairly large, a DMSP-17 SSMIS Microwave (85 GHz) image at 2217 UTC from the CIMSS Tropical Cyclones site (below) showed that no organized core of deep convection remained as the storm began to move across colder waters (Sea Surface Temperature | Ocean Heat Content) and encounter a more hostile environment of increasing deep-layer wind shear.

DMSP-17 SSMIS Microwave (85 GHz) image at 2217 UTC [click to enlarge]

DMSP-17 SSMIS Microwave (85 GHz) image at 2217 UTC [click to enlarge]

GOES-16 CIMSS Natural Color RGB images, with and without an overlay of Aerosol Optical Depth [click to play animation | MP4]

GOES-16 CIMSS Natural Color RGB images, with and without an overlay of Aerosol Optical Depth [click to play animation | MP4]

A larger-scale view of GOES-16 CIMSS Natural Color RGB images — with and without an overlay of Aerosol Optical Depth (above) showed that an elongated plume of smoke stretched westward from New York and Pennsylvania to parts of Wisconsin, Illinois and Iowa. Upward-looking lidar data from the University of Wisconsin – Madison (below) depicted a thick layer of smoke between altitudes of 2-6 km.

Plots of lidar backscatter and depolarization from 12 UTC o n 22 September to 00 UTC on 23 September [click to enlarge]

Plots of lidar backscatter (top) and depolarization (bottom) from 12 UTC on 22 September to 00 UTC on 23 September [click to enlarge]

Hurricane Teddy rapidly intensifies to a Category 4 storm

September 17th, 2020 |

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (with and without an overlay of GLM Flash Extent Density) [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (with and without an overlay of GLM Flash Extent Density) [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 — with and without an overlay of GLM Flash Extent Density (above) showed Hurricane Teddy as it rapidly intensified (ADT | SATCON ) to a Category 4 storm on 17 September 2020. The coldest cloud-top infrared brightness temperatures were in the -80 to -85ºC range.

Metep-A ASCAT surface scatterometer wind speeds were as high as 74 knots in the northwestern portion  of the eyewall (below).

GOES-16 “Red” Visible (0.64 µm) image, with plots of Metop-A ASCAT winds [click to enlarge]

GOES-16 “Red” Visible (0.64 µm) image, with plots of Metop-A ASCAT winds [click to enlarge]

Microwave (85 GHz) DMSP-17 (at 1023 UTC), GMI (at 1720 UTC) and DMSP-18 (at 2034 UTC) images from the CIMSS Tropical Cyclones site are shown below.

DMSP-17 SSMI Microwave (85 GHz) image at 1023 UTC [click to enlarge]

DMSP-17 SSMI Microwave (85 GHz) image at 1023 UTC [click to enlarge]

GMI Microwave (85 GHz) image at 1720 UTC [click to enlarge]

GMI Microwave (85 GHz) image at 1720 UTC [click to enlarge]

DMSP-18 SSMI Microwave (85 GHz) image at 2034 UTC [click to enlarge]

DMSP-18 SSMI Microwave (85 GHz) image at 2034 UTC [click to enlarge]

Category 4 Hurricane Laura makes landfall in Louisiana

August 27th, 2020 |

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (with and without an overlay of GLM Flash Extent Density) [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (with and without an overlay of GLM Flash Extent Density) [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 — with and without an overlay of GLM Flash Extent Density (above) showed Category 4 Hurricane Laura as it made landfall near Cameron, Louisiana around 0600 UTC on 27 August 2020. The GLM data showed intermittent lightning activity along the inner eyewall region of the hurricane.

Strong outer convective bands ahead of Laura’s landfall produced isolated tornadoes as it moved onshore (SPC Storm Reports). Peak wind gusts included 116 knots or 133 mph at Lake Charles at 0642 UTC (in addition, Lake Charles reported another peak wind gust of 113 knots or 130 mph at 0703 UTC). Strong winds associated with the northern portion of the eyewall destroyed the Lake Charles radar (YouTube video) — the final reflectivity and velocity images at 0553 UTC (12:53 am CDT) are shown here (the 0.5-degree inbound and outbound radial velocity values were as high as 160-162 mph).


Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0751 UTC (credit William Straka, CIMSS) [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0751 UTC (credit William Straka, CIMSS) [click to enlarge]

A toggle between Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0751 UTC (above) revealed the nighttime glow of lights from Lake Charles (since that city was near the inside edge of the eye of Hurricane Laura at that time) — in other locations across Louisiana and far eastern Texas, the signature of city lights was muted to varying degrees by the storm’s dense cloud cover and precipitation.

The corresponding Suomi NPP ATMS Microwave (88.2 GHz) and MiRS Rainfall Rate images at 0751 UTC (below) depicted the pattern of precipitation that was spreading inland.

Suomi NPP ATMS Microwave (88.2 GHz) and MiRS Rainfall Rate images at 0751 UTC (credit William Straka, CIMSS) [click to enlarge]

Suomi NPP ATMS Microwave (88.2 GHz) and MiRS Rainfall Rate images at 0751 UTC (credit William Straka, CIMSS) [click to enlarge]

DMSP-17 and GMI Microwave (85 GHz) images from the CIMSS Tropical Cyclones site (below) showed the structure of Laura several hours before landfall.

DMSP-17 SSMI Microwave (85 GHz) image at 0054 UTC [click to enlarge]

DMSP-17 SSMI Microwave (85 GHz) image at 0054 UTC [click to enlarge]

GMI Microwave (85 GHz) image at 0255 UTC [click to enlarge]

GMI Microwave (85 GHz) image at 0255 UTC [click to enlarge]

An animation of the MIMIC-TC product during the 26-27 August period (below) showed the deterioration of the eyewall structure after landfall.

MIMIC-TC product during the 26-27 August period [click to enlarge]

MIMIC-TC product during the 26-27 August period [click to enlarge]

Prior to making landfall, Laura had been moving across the warm waters of the Gulf of Mexico — however, it began to encounter an environment characterized by increasingly unfavorable deep-layer wind shear as it approached the Gulf Coast (below) which likely prevented further intensification.

GOES-16 Infrared Window (11.2 µm) images, with an overlay of deep-layer wind shear [click to enlarge]

GOES-16 Infrared Window (11.2 µm) images, with an overlay of deep-layer wind shear [click to enlarge]