Warm Seclusion off the US East Coast
1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (above) displayed the small eye-like feature associated with a warm seclusion that developed about 200 miles southeast of the New Jersey coast on 15 January 2023. Areas of deep convection around the periphery of the seclusion occasionally exhibited cloud-top infrared brightness temperatures around -50ºC.During the preceding nighttime hours, a comparison of Suomi-NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images valid at 0718 UTC (below) provided a view of the cyclone as it was beginning to transition to its occluded phase — and the Sea Surface Temperature derived product indicated that water temperatures in the general vicinity were in the upper 60s to low 70s F (suggesting that the system was very near the axis of the Gulf Stream). One isolated bright lightning streak was seen in the Day/Night Band image, associated with a thunderstorm located near the warm front (which exhibited a cloud-top infrared brightness temperature of -56ºC).