Ice dam in Lake Erie

January 19th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with hourly surface wind barbs plotted in yellow and wind gusts (knots) plotted in cyan [click to play animation]

Thanks to Dave Zaff (NWS Buffalo) for the email alerting us to an ice dam that had formed across the eastern portion of Lake Erie on 19 January 2018 — GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed that the northeastward drift of ice floes was effectively being blocked by this ice dam feature.

A toggle between 250-meter resolution Terra MODIS True-color and False-color Red-Green-Blue (RGB) images from the MODIS Today site (below) provided a more detailed view of the Lake Erie ice dam and upwind drift ice at 1615 UTC. Snow and ice appear as shades of cyan in the False-color image, in contrast to supercooled water droplet clouds which are shades of white.

Terra MODIS True-color and False-color RGB images [click to enlarge]

Terra MODIS True-color and False-color RGB images; red arrows denote the location of the ice dam [click to enlarge]

The Terra MODIS Visible (0.65 µm) image with an overlay of RTMA surface winds (below) showed the southwesterly flow across the long axis of the lake.

Terra MODIS Visible (0.65 µm) image with surface METAR reports and RTMA surface winds [click to enlarge]

Terra MODIS Visible (0.65 µm) image with surface METAR reports and RTMA surface winds [click to enlarge]

A toggle between 1607 UTC Terra MODIS and 1757 UTC Suomi NPP VIIRS Visible images (below) showed the motion of the lake drift ice during that time period.

Terra MODIS and Suomi NPP VIIRS Visible images, with METAR surface reports [click to enlarge]

Terra MODIS and Suomi NPP VIIRS Visible images, with METAR surface reports [click to enlarge]

Blowing snow in North Dakota and Minnesota

January 11th, 2018 |

GOES-16

1-minute GOES-16 “Red” Visible (0.64 µm, left) and Near-Infrared “Snow/Ice” (1.61 µm, right) images, with plots of hourly surface wind barbs in cyan and surface weather type in yellow [click to play MP4 animation]

Several inches of new snow followed by strong northerly winds led to widespread blizzard conditions across the Red River Valley of North Dakota and Minnesota on 11 January 2018 (NWS Grand Forks summary). A GOES-16 (GOES-East) Mesoscale Sector had been positioned over the Upper Midwest to monitor the winter storm, providing images at 1-minute intervals — and a comparison of “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (above) showed the development of horizontal convective rolls that are a common feature associated with blowing snow.

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).

Nighttime views of lake effect snow bands over Lake Superior

January 6th, 2018 |

Suomi NPP VIIRS Day/Night Band (0.7 µm) images, with morning minimum temperatures at Embarrass, Minnesota [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) images, with morning minimum temperatures at Embarrass, Minnesota [click to enlarge]

Shown above are detailed nighttime views of multiple lake effect snow (LES) bands over Lake Superior, provided by Suomi NPP VIIRS Day/Night Band (0.7 µm) images on 04 January, 05 January and 06 January 2018. These “visible images at night” were possible due to ample illumination by the Moon, which was in the Waning Gibbous phase (at 92% of Full on 04 January, 84% of Full on 05 January and 75% of Full on 06 January). The continued flow of arctic air across the still-unfrozen waters of Lake Superior (and the other unfrozen Great Lakes) was responsible for the formation of these and a variety of other LES bands.

For perspective, the daily morning minimum temperatures at Embarrass, Minnesota are also plotted on the images — on these 3 days Embarrass was the coldest official site in the US (including Alaska).

The VIIRS images were captured by the Space Science and Engineering Center direct broadcast ground station.