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]

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