Tropical Invest 96P and Tropical Cyclone Vicky near American Samoa

February 18th, 2020 |

GOES-17

GOES-17 “Clean” Infrared Window (10.35 µm) images, 16-18 February [click to play animation | MP4]

GOES-17 (GOES-West) “Clean” Infrared Window (10.35 µm) images (above) showed the movement of numerous thunderstorms across American Samoa during the 16-18 February 2020 period. This deep convection was being forced by an active South Pacific Convergence Zone or “Monsoon Trough” (surface analysis) and the presence of Tropical Invest 96P (named TD07F by the Fiji Met Service / Nadi Tropical Cyclone Centre) northwest of Samoa. Due to outflow from a nearby thunderstorm, winds gusted to 60 knots at Pago Pago, American Samoa (NSTU) at 11 UTC on 17 February.

With an increasing probability of Invest 96P becoming better organized (aided by low values of deep-layer wind shear along with modest upper-level divergence), a GOES-17 Mesoscale Domain Sector was positioned over the Samoan Islands on 18 February — providing “Red” Visible (0.64 µm) and “Clean” Infrared Window images at 1-minute intervals (below). During this period, the coldest convective overshooting tops exhibited infrared brightness temperatures in the -80 to -85ºC range (which corresponded to the tropopause temperatures seen in Pago Pago rawinsonde data).

GOES-17 "Red" Visible (0.64 µm) and "Clean" Infrared Window (10.35 µm) images, 18 February [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images with surface plots for Pago Pago, American Samoa on 18 February [click to play animation | MP4]

===== 20 February Update =====

 GOES-17 "Red" Visible (0.64 µm) and "Clean" Infrared Window (10.35 µm) images with surface plots for Pago Pago, American Samoa on 18 February [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images with surface plots for Pago Pago, American Samoa on 20 February [click to play animation | MP4]

Another tropical depression (Invest 97P/TD09F) developed along the active Monsoon Trough on 20 February (surface analyses), intensifying just south of American Samoa to become Tropical Cyclone Vicky (TC 17P) as of 18 UTC (JTWC advisory). Once again a GOES-17 Mesoscale Sector was positioned over the region — “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed the gradual organization of Vicky; the coldest cloud-top infrared brightness temperature of convective overshooting tops was -90ºC. Surface observations revealed a wind gust to 65 knots at Pago Pago, American Samoa just before 20 UTC.

GOES-17 Infrared Window (11.2 µm) images from the CIMSS Tropical Cyclones site (below) showed that Vicky was moving through an environment characterized by of low values of Deep Layer Wind Shear, a favorable factor for further intensification.

GOES-17 Infrared Window (11.2 µm) images with contours of Deep Layer Wind Shear (click to enlarge]

GOES-17 Infrared Window (11.2 µm) images with contours of Deep Layer Wind Shear [click to enlarge]

Hourly MIMIC Total Precipitable Water images during the 16-20 February period (below) displayed the northwest-to-southeast oriented band of elevated moisture along the South Pacific Convergence Zone (or Monsoon Trough). The Samoan Islands are centered near 14.3° S latitude, 170.1° W longitude.

Hourly MIMIC Total Precipitable Water product during the 16-20 February period [click to play animation | MP4]

Hourly MIMIC Total Precipitable Water product during the 16-20 February period [click to play animation | MP4]

Cyclone Damien makes landfall in Western Australia

February 8th, 2020 |

Himawari-8

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

2.5-minute rapid scan JMA Himawari-8 “Clean” Infrared Window (10.4 µm) images (above) showed Cyclone Damien making landfall as a Category 2 storm in Western Australia on 08 February 2020. Well west of the storm center, winds gusted to 49 knots at Barrow Island (YBWX). The eye remained intact for several hours after Damien moved inland.

GCOM-W1 AMSR2 Microwave (85 GHz) imagery from the CIMSS Tropical Cyclones site (below) showed the eye at 1710 UTC.

GCOM-W2 AMSR2 Microwave (85 GHz) image [click to enlarge]

GCOM-W2 AMSR2 Microwave (85 GHz) image [click to enlarge]

Just prior to landfall. cloud-top gravity waves were evident in VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP, as viewed using RealEarth (below).

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

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


Tropical Storm Damien was also seen in the first-light image from Russia’s Elecro-L3 satellite, a few hours before Damien reached Category 1 hurricane intensity.

Tropical Cyclone Tino in the South Pacific Ocean

January 16th, 2020 |

Himawari-8

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

JMA Himawari-8 “Clean” Infrared Window (10.4 µm) images (above) showed the development of Tropical Cyclone Tino in the South Pacific Ocean on 16 January 2020. Tino was moving southeast toward the island nation of Fiji. Convection around the tropical cyclone exhibited extensive cloud-top infrared brightness temperatures (IRBTs) of -90ºC and colder (shades of yellow embedded within the dark purple enhancement), including a few red -100ºC pixels at 1630 UTC.

Plots of rawinsonde data from Fiji (below) showed a tropopause around 100 hPa, where the temperature was around -85ºC — so the tropical overshooting tops with IRBTs in the -90 to -100ºC range were extending into the stratosphere.

Plots of rawinsonde data from Fiji [click to enlarge]

Plots of rawinsonde data from Nandi, Fiji [click to enlarge]

Plots of deep-layer wind shear from the CIMSS Tropical Cyclones site (below) indicated that Tino gradually intensified within a narrow zone of light shear.

Plots of deep-layer wind shear [click to enlarge]

Plots of deep-layer wind shear [click to enlarge]

===== 17 January Update =====

GOES-17

GOES-17 “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

A GOES-17 (GOES-West) Mesoscale Domain Sector was positioned over Tropical Cyclone Tino on 17 January, providing images at 1-minute intervals — “Clean” Infrared Window (10.35 µm) images (above) showed the continued development of convective bursts, which at times exhibited IRBT values as cold as -100ºC (red pixels on the coldest portion of the enhancement).

Typhoon Kammuri makes landfall in the Philippines

December 2nd, 2019 |

Himawari-8

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

2.5-minute interval rapid scan JMA Himawari-8 AHI “Clean” Infrared (10.4 µm) images (above) showed Typhoon Kammuri as it made landfall in the Philippines around 1500 UTC on 02 December 2019. Kammuri rapidly intensified from a Category 2 to a Category 4 storm (ADT | SATCON) shortly before landfall — it had been moving over very warm water (Sea Surface Temperature | Ocean Heat Content) in the Philippine Sea.

VIIRS Infrared Window (11.45 µm) from Suomi NPP at 1707 UTC and NOAA-20 at 1757 UTC viewed using RealEarth (below) depicted Kammuri 2-3 hours after landfall.

VIIRS Infrared Window (11.45 µm) from Suomi NPP at 1707 UTC and NOAA-20 at 1757 UTC [click to enlarge]

VIIRS Infrared Window (11.45 µm) from Suomi NPP at 1707 UTC and NOAA-20 at 1757 UTC [click to enlarge]

GCOM-W1 AMSR2 Microwave (85 GHz) imagery at 1725 UTC (below) revealed a large eye and nearly circular eyewall.

GCOM-W1 AMSR2 Microwave (85 GHz) image at 1725 UTC [click to enlarge]

GCOM-W1 AMSR2 Microwave (85 GHz) image at 1725 UTC [click to enlarge]