Tropical Invest 96P and Tropical Cyclone Vicky near American Samoa

By Scott Bachmeier • 18 February 2020

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

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 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 20 February [click to play animation | MP4]

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]

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

Categories: GOES-17, Satellite winds, Tropical cyclones