Tropical Invest 90E becomes Tropical Storm Andres

May 8th, 2021 |

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

GOES-17 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) images (above) showed the convective banding associated with Tropical Invest 90E in the East Pacific Ocean on 08 May 2021. Invest 90E was centered along a northward bulge in the ITCZ/Monsoon Trough (below).

GOES-17 “Clean” Infrared Window (10.35 µm) image (Mesoscale Sector), with an overlay of the 12 UTC surface analysis [click to enlarge]

Invest 90E was located over water characterized by modest Ocean Heat Content and very warm Sea Surface Temperature values (below), favorable factors for further intensification.

Ocean Heat Content and Sea Surface Temperature [click to enlarge]

Ocean Heat Content and Sea Surface Temperature [click to enlarge]

===== 09 May Update =====

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

GOES-17 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

1-minute GOES-17 Infrared and Visible images on 09 May (above) showed the period where Invest 90E intensified to a Tropical Depression (at 0900 UTC) and then to Tropical Storm Andres at 1500 UTC — the earliest calendar year tropical storm on record in the East Pacific basin. The convective overshooting tops occasionally exhibited infrared brightness temperatures of -90ºC or colder (yellow pixels embedded within dark purple regions).

A GOES-17 Infrared / Water Vapor Difference product (reference) from the CIMSS Tropical Cyclones site (below) highlighted areas of deep convection where overshooting tops were likely penetrating the tropopause (yellow to red enhancement).

GOES-17 Infrared - Water Vapor Difference product [click to enlarge]

GOES-17 Infrared – Water Vapor Difference product [click to enlarge]

GOES-17 Infrared images, with an overlay of deep-layer wind shear (below) indicated that Andres was approaching an environment of moderate to high shear, which would limit intensification.

GOES-17 Infrared images, with an overlay of deep-layer wind shear [click to enlarge]

GOES-17 Infrared images, with an overlay of deep-layer wind shear [click to enlarge]

===== 10 May Update =====

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

GOES-17 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

On 10 May, 1-minute GOES-17 Infrared and Visible images (above) showed that after one final convective burst, the low-level center of Tropical Storm Andres became exposed — and the storm was then downgraded to a Tropical Depression at 2100 UTC.

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