1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed Tropical Depression 27 as further intensified to become Tropical Storm Epsilon at 15 UTC on 19 October 2020. While the low-level circulation (LLC) generally remained exposed during that time, deep convection was increasing around the LLC (including a small convective burst near the storm center forming around 1630 UTC).

A GOES-16 Visible image with plots of available NOAA-20 NUCAPS profiles (above) showed one valid infrared (CrIS) + microwave (ATMS) sounding (green dot) just southeast of the center of Epsilon at 1640 UTC — that sounding profile (below) revealed a moist (PW = 1.95″) and unstable (MU CAPE = 1066 J/kg, and LI = -3) atmosphere just after the time of development of the convective burst near Epsilon’s center.

GOES-16 Visible images with overlays of deep-layer wind shear and GLM Flashes from the CIMSS Tropical Cyclones site (below) indicated that Epsilon was in an environment of moderate shear, with limited lighting activity near the storm center.

A toggle between the MIMIC Total Precipitable Water and Saharan Air Layer products (below) showed that Epsilon was embedded within a pocket of abundant moisture, with dry air situated to the north and northwest.

Tropical Storm Epsilon was located over water having Sea Surface Temperature values around 28ºC and a modest Ocean Heat Content (below).

#Epsilon has formed in central subtropical Atlantic – the earliest 26th Atlantic named storm formation on record. Prior record was November 22, 2005 (Delta). Additional storm in October 2005 added after the season, which is why Epsilon breaking record set by Delta. #hurricane pic.twitter.com/NeyB1l6yrD

— Philip Klotzbach (@philklotzbach) October 19, 2020