Ice floes in Chesapeake Bay

January 7th, 2018 |

Landsat-8 false-color RGB image [click to enlarge]

Landsat-8 false-color RGB image [click to enlarge]

In the wake of the explosive cyclogenesis off the East Coast of the US on 04 January 2018, very cold air began to spread across much of the eastern half of the Lower 48 states. Focusing on the Hampton Roads area of southeastern Virginia, satellite imagery began to show the formation of ice in the rivers and bays. On 06 January, a 30-meter resolution Landsat-8 false-color Red-Green-Blue (RGB) image viewed using RealEarth (above) revealed some of this ice — in particular, long narrow ice floes (snow and ice appear as shades of cyan) that likely emerged from the Back River (northeast of Hampton) and were drifting northward and southward just off the coast of the Virginia Peninsula.

On the following day (07 January), 250-meter resolution Terra MODIS true-color and false-color RGB images from the MODIS Today site (below) showed that a larger V-shaped ice floe was located just southeast of the Peninsula, with its vertex pointed toward the Hampton Roads Bridge-Tunnel (HRBT). Snow and ice also appear as shades of cyan in the MODIS false-color image.

Terra MODIS true-color and false-color RGB images [click to enlarge]

Terra MODIS true-color and false-color RGB images [click to enlarge]

07 January also happened to be the last full day of imagery to be broadcast by the GOES-13 satellite — a comparison of 1-minute Mesoscale Sector GOES-16 (GOES-East) Visible (0.64 µm) and 15-30 minute interval GOES-13 Visible (0.63 µm) images (below) showed that the V-shaped ice floe continued to drift southwestward toward the HRBT. However, it was difficult to tell whether the ice feature made it over and past the tunnel; even with the improved GOES-16 Visible spatial resolution (0.5 km at satellite sub-point, compared to 1.0 km for GOES-13) and the 1-minute rapid image scans, the ice floe became harder to track during the afternoon hours before high clouds began to overspread the region.

"GOES-16

GOES-16 Visible (0.64 µm, left) and GOES-13 Visible (0.63 µm, right) images, with hourly surface air temperatures (ºF) plotted in yellow [click to play MP4 animation]

However, a close examination of Suomi NPP VIIRS true-color and false-color images at 1826 UTC (below) indicated that some of the ice had indeed moved westward past Fort Monroe (on the far southeastern tip of the Peninsula) and over/past the HRBT.

Suomi NPP VIIRS true-color and false-color RGB images [click to enlarge]

Suomi NPP VIIRS true-color and false-color RGB images [click to enlarge]

On the topic of cold temperatures in southeastern Virginia, a new daily record low of -3 ºF was set at Richmond on the morning of 07 January, and at Norfolk new daily record low and record low maximum temperatures were set (10 ºF and 23 ºF, respectively).