A prescribed burn in Montana, as viewed from GOES-15, GOES-16 and GOES-13

January 2nd, 2018 |

GOES-15 (left), GOES-16 (center) and GOES-13 (right) Shortwave Infrared (3.9 µm) images, with plots of hourly surface reports [click to play MP4 animation]

GOES-15 (left), GOES-16 (center) and GOES-13 (right) Shortwave Infrared (3.9 µm) images, with plots of hourly surface reports [click to play MP4 animation]

A prescribed burn the SureEnough fire — in central Montana was viewed by GOES-15 (GOES-West), GOES-16 (GOES-East) and GOES-13 Shortwave Infrared (3.9 µm) imagery on 02 January 2018. The images are shown in the native projection for each of the 3 satellites.

Due to the improved spatial resolution of the GOES-16 3.9 µm Shortwave Infrared band (2 km at satellite sub-point, vs 4 km for GOES-15 and GOES-13) and the more frequent image scans (routinely every 5 minutes over CONUS for GOES-16), an unambiguous thermal anomaly or fire “hot spot” was first evident on GOES-16 at 1707 UTC, just southeast of Lewistown (station identifier KLWT). The GOES-16 fire thermal signature was also hotter (black pixels) compared to either GOES-15 or GOES-13.

GOES-13 will cease transmission on 3 January 2018 [Update: 8 January]

January 2nd, 2018 |

GOES-13 Visible (0.63 µm) Image, 1745 UTC on 2 January 2018 (Click to enlarge)

The GOES-13 Satellite, operational as GOES-East from April 2010 through December 2017 (with a notable interruption) will be turned off sometime after 1500 UTC on Wednesday 3 January 2018. (Update: due to an impending East Coast winter storm, GOES-13 deactivation was postponed to 8 January)

The visible Full Disk image above, from 1745 UTC on 2 January 2018, is one of the last fully illuminated visible image the satellite will process.  (The first processed full disk visible image, from 22 June 2006, can be viewed here.)

On 28 December 2017, GOES-13 imagery included a view of the Moon, as shown here (and zoomed in here).  Future GOES-East imagery from GOES-16 will not include images of the Moon.  GOES-16 will scan the moon when it is near the horizon (and there are occasional GOES-16 mesoscale sectors placed over the Moon for calibration purposes).  However, GOES-16 imagery is remapped to Earth points before being broadcast to the public.  The Moon (happily) is not on the Earth and its points will not be remapped.

Thank you GOES-13 for your long years of service.  A full-resolution version of the image above is available here.

Snowfall across the Deep South

December 9th, 2017 |

GOES-13 Visible (0.63 µm) images [click to play animation]

GOES-13 Visible (0.63 µm) images [click to play animation]

GOES-13 (GOES-East) Visible (0.63 µm) images (above) showed a broad swath of snow cover from Louisiana to Virginia on 09 December 2017. Some notable storm total accumulations included 6.5 inches at Kentwood, Louisiana, 7.0 inches at Bay Springs, Mississippi, 12.0 inches at Jacksonville, Alabama, 2.0 inches at Century, Florida, 18.0 inches at Mountain City, Georgia, 7.0 inches near Roan Mountain, Tennessee, and 25 inches at Mt. Mitchell State Park, North Carolina. Daily record snowfall accumulations included a Trace at New Orleans, Louisiana, 5.1 inches at Jackson, Mississippi and 1 inch at Mobile, Alabama.

A closer view of GOES-13 visible images (below) showed the band of snow cover across Louisiana, Mississippi and Alabama. Much of the the snow melted quickly, due to warm ground temperatures and a full day of sun.

GOES-13 Visible (0.63 µm) images, with station identifiers plotted in yellow [click to play animation]

GOES-13 Visible (0.63 µm) images, with hourly surface reports plotted in yellow [click to play animation]

A more detailed view of the snow cover was provided by 250-meter resolution Terra and Aqua MODIS true-color Red-Green-Blue (RGB) images from the SSEC MODIS Direct Broadcast site (below). Note that snow cover was evident all the way to the Gulf Coast at Atchafalaya Bay, Louisiana early in the day.

Terra and Aqua MODIS true-color RGB images of the central Gulf Coast region [click to enlarge]

Terra and Aqua MODIS true-color images of the central Gulf Coast region [click to enlarge]

Terra and Aqua MODIS true-color RGB images, centered over Atchafalaya Bay, Louisiana [click to enlarge]

Terra and Aqua MODIS true-color RGB images, centered over Atchafalaya Bay, Louisiana [click to enlarge]

Terra and Aqua MODIS true-color images, centered over New Orleans, Louisiana [click to enlarge]

Terra and Aqua MODIS true-color images, centered over New Orleans, Louisiana [click to enlarge]

Terra MODIS true-color image, centered over Atlanta, Georgia [click to enlarge]

Terra MODIS true-color image, centered over Atlanta, Georgia [click to enlarge]

It is interesting to note that with the aid of reflected moonlight — the Moon was in the Waning Gibbous phase, at 59% of Full — the Suomi NPP VIIRS Day/Night Band (0.7 µm) was able to detect the area of deeper snow cover across southeastern Louisiana and southern Mississippi at 0741 UTC or 1:41 AM local time; this snow cover was then seen during the following morning on GOES-13 Visible (0.63 µm) imagery at 1440 UTC or 8:40 AM local time (below). A VIIRS instrument is part of the payload on the recently-launched JPSS-1/NOAA-20 satellite.

Suomi NPP VIIRS Day/Night Band (0.7 µm) and GOES-13 Visible (0.63 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and GOES-13 Visible (0.63 µm) images [click to enlarge]

Snowfall in southern Texas

December 8th, 2017 |

GOES-13 Visible (0.63 µm, left) and Shortwave Infrared (3.9 µm, right) images, with hourly plots of surface reports [click to play animation]

GOES-13 Visible (0.63 µm, left) and Shortwave Infrared (3.9 µm, right) images, with hourly plots of surface reports [click to play animation]

The combination of lift from an upper-level trough and cold air behind the passage of a surface cold front  set the stage for accumulating snow across far southern Texas on 08 December 2017. As the clouds cleared, GOES-13 (GOES-East) Visible (0.63 µm) and Shortwave Infrared (3.9 µm) images (above) revealed a narrow swath of snow cover running northeastward from the Rio Grande River toward Corpus Christi — the highest snowfall total associated with this feature was 7.0 inches near Corpus Christi. Daily snowfall records included 0.3 inch at Brownsville and 1.0 inch at Corpus Christi.

A toggle between Terra MODIS true-color and false-color Red-Green-Blue (RGB) images from RealEarth (below) showed the southwestern portion of this band of snow cover (which appeared as darker shades of cyan in the false-color image).

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]

Farther to the north, another southwest-to-northeast oriented band of snow cover was seen on Terra MODIS true-color and false-color RGB images (below), stretching from San Antonio to Austin to College Station. The highest snowfall total there was 5.0 inches (NWS Austin/San Antonio summary),

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

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