GOES-16 Shortwave Infrared (3.9 µm) images, with hourly plots of surface wind barbs (cyan) and wind gusts (in knots, red) [click to play animation | MP4]

GOES-16 (GOES-East) Shortwave Infrared (3.9 µm) images (above) showed rapid growth of the thermal anomaly — cluster of hot pixels, red enhancement — associated with the Greenwood Fire in northeast Minnesota on 23 August 2021. With gusty winds in the wake of a frontal passage, the fire exhibited extreme behavior on this day, growing in size from 8862 acres to 19,493 acres. Vegetation was near a historic level of dryness, due to ongoing drought conditions. 

GOES-16 True Color RGB images created using Geo2Grid (below) displayed the dense smoke plume from the Greenwood Fire (as well as other plumes from wildfires farther to the north in Minnesota and Ontario) as they moved eastward.

GOES-16 True Color RGB images [click to play animation | MP4]

View only this post Read Less

GOES-16 Night Fog BTD (10.3-3.9 µm) and “Red” Visible (0.64 µm) images, with and without plots of Ceiling/Visibility [click to play animation | MP4]

GOES-16 (GOES-East) Night Fog BTD (10.3-3.9 µm) and “Red” Visible (0.64 µm) images on 23 August 2021 (above) showed the nighttime formation of widespread river valley fog across parts of the Mid-South and adjacent Appalachians — followed by morning fog dissipation once solar heating initiated boundary layer mixing. With surface high pressure in place over the area, light winds helped to provide ideal conditions for strong radiational cooling and fog formation; note that the surface visibility was reduced to zero at a few sites in Tennessee. Much of that same region had recently experienced heavy rainfall (7-day accumulation | 7-day percent of normal), particularly in Tennessee as discussed in this blog post.

Suomi NPP VIIRS Day/Night Band (0.7 µm) images (below) displayed a subtle signature of some of the tendrils of river valley fog, and their growth during the ~90 minutes between the two satellite overpasses.

Suomi NPP VIIRS Day/Night Band (0.7 µm) images, with plots of Ceiling/Visibility [click to enlarge]   

View only this post Read Less

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

 1–minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images and “Clean” Infrared Window (10.35 µm) images (above) showed Tropical Storm Henri as it moved over Block Island (station identifier KBID) around 1500 UTC and then made landfall along the coast Rhode Island around 1615 UTC on 22 August 2021. Infrared images depicted the coldest cloud tops of deep convection moving northwestward across Connecticut. Heavy rainfall and strong winds were reported across parts of the Northeast US as Henri moved inland. 

A GMI Microwave (85 GHz) image from the CIMSS Tropical Cyclones site (below) displayed an arc of heavier precipitation to the north, east and south of the inland storm center at 1635 UTC.

GMI Microwave (85 GHz) image [click to enlarge]

Suomi NPP VIIRS True Color RGB and Infrared Window (11.45 µm) images at 1813 UTC (below) were acquired and processed by the CIMSS Direct Broadcast ground station — and revealed cloud-top infrared brightness temperatures as cold as -71ºC near the Massachusetts/Connecticut border.  

Suomi NPP VIIRS True Color RGB and Infrared Window (11.45 µm) images [click to enlarge]

View only this post Read Less

Overpasses from NOAA-20 (0601 and 0741 UTC) bracket an overpass from Suomi-NPP (0651 UTC), above, to provide excellent night time visual imagery animation over Hurricane Henri as it moved northward towards landfall over southern New England. It is difficult to pinpoint the center of the storm in this imagery. Per the National Hurricane Center, the 0600 UTC location was at 39.3 N, 71.0 W.

Radar imagery at 1143 UTC on 22 August, below, shows the storm south of Block Island

GOES-16 Visible imagery (from CSPP Geosphere) just after sunrise on 22 August show the storm affecting much of Southern New England.

View only this post Read Less