Welcome back Suomi NPP!

August 19th, 2022 |
Suomi NPP Day Night Band visible (0.7 um) Imagery from two morning overpasses on 19 August 2022 as viewed from the San Juan (PR) Direct Broadcast site

The Suomi NPP satellite experienced an anomaly at ~1630 UTC on 26 June that caused all instruments to go into ‘safe mode’. NOAA Engineers have successfully re-started the instruments. The Direct Broadcast signal resumed on 11 August, and NOAA/NESDIS proclaimed VIIRS Sensor Data Record (SDR) data operational as of 18 August (information on this outage is available here). The above Day Night Band image, from RealEarth, shows Suomi NPP data from the San Juan Direct Broadcast site. The tropical Atlantic remains quiet.

Sea ice in the Bering Sea

August 14th, 2022 |

GOES-18 True Color RGB images [click to play MP4 animation]

GOES-18 (GOES-West) True Color RGB images viewed using CSPP GeoSphere (above) showed the motion of sea ice filaments that had moved southward through the Bering Strait and into the northern Bering Sea (just off the coast of Siberia) on 14 August 2022. 

A sequence of 375-meter resolution VIIRS False Color RGB images from NOAA-20 and Suomi-NPP viewed using RealEarth (below) displayed a more detailed view of the sea ice (brighter shades of cyan).

VIIRS False Color RGB images from NOAA-20 and Suomi-NPP [click to enlarge]

A 30-meter resolution Landsat-8 False Color RGB image (below) provided an even more detailed depiction of the sea ice structure and coverage.

Landsat-8 False Color RGB image [click to enlarge]

H/T to Rick Thoman (University of Alaska, Fairbanks), who pointed out that this sea ice was first evident in the Bering Sea on 09 August.

Record 24-hour rainfall in Sioux Falls, South Dakota

August 7th, 2022 |

GOES-16 “Clean” Infrared Window (10.35 µm) images [click to play animated GIF | MP4]       

1-minute Mesoscale Domain Sector (from 0600-0800 UTC) and 5-minute CONUS Sector (from 0801-1301 UTC) GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images (above) showed clusters of thunderstorms that developed and moved eastward across parts of South Dakota, Minnesota and Iowa on 07 August 2022. In fact, these storms contributed to a new 24-hour rainfall record (5.44 inches) being set at Sioux Falls, South Dakota. Much of this record rainfall occurred during the 0600-1300 UTC period shown by the GOES-16 imagery.

Shortly after flash flooding had been reported in Sioux Falls, a toggle between NOAA-20 VIIRS Infrared (11.45 µm) and GOES-16 ABI “Clean” Infrared Window (10.35 µm) images valid at 0826 UTC (below) revealed that the coldest NOAA-20 cloud-top infrared brightness temperatures near Sioux Falls at that time were -83ºC, compared to -74ºC with GOES-16 (identical color enhancements were applied to both images). The northwestward shift in GOES-16 image cloud-top features was associated with parallax (which in this case was a distance of 22 km for a cloud-top height of 50,000 feet).

NOAA-20 Infrared Window (11.45 µm) and GOES-16 “Clean” Infrared Window (10.35 µm) images valid at 0826 UTC [click to enlarge]  

The MIMIC Total Precipitable Water product at 0300, 0600, 0900 and 1200 UTC — visualized using RealEarth — is shown below. TPW values near Sioux Falls peaked at 57 mm (or 2.24 inches) at 0900 UTC.

MIMIC Total Precipitable Water product at 03, 06, 09 and 12 UTC (with plots of surface fronts/troughs) [click to enlarge]

30-second imagery of severe thunderstorms across the Upper Midwest

August 3rd, 2022 |

GOE S-16 “Red” Visible (0.64 µm) images, with time-matched SPC Storm Reports plotted in red [click to play animated GIF | MP4]

Overlapping 1-minute GOES-16 (GOES-East) Mesoscale Domain Sectors provided 30-second “Red” Visible (0.64 µm) images (above), which included time-matched plots of SPC Storm Reports — showing clusters of thunderstorms that moved eastward across parts of Illinois, Indiana and Lower Michigan on 03 August 2022.

The corresponding 30-second GOES-16 “Clean” Infrared Window (10.35 µm) images (below) indicated that the coldest overshooting tops exhibited infrared brightness temperatures around -80ºC (violet pixels within areas of brighter white enhancement).

GOES-16 “Clean” Infrared Window (10.35 µm) images, with time-matched SPC Storm Reports plotted in cyan [click to play animated GIF | MP4]

In a toggle between NOAA-20 VIIRS Infrared (11.45 µm) and GOES-16 ABI “Clean” Infrared Window (10.35 µm) images valid at 1924 UTC (below), the northwestward shift in GOES-16 image cloud-top features was associated with parallax (which in this case was a distance around 18-19km for the maximum Cloud Top Heights of 50,000-52,000 feet). The coldest NOAA-20 cloud-top infrared brightness temperatures at that time were around -84ºC (over far southern Lake Michigan), compared to around -77ºC with GOES-16 (identical color enhancements were applied to both images).

NOAA-20 Infrared Window (11.45 µm) and GOES-16 “Clean” Infrared Window (10.35 µm) images valid at 1924 UTC [click to enlarge]

However, in a toggle between NOAA-20 Infrared Window (11.45 µm) and GOES-16 Cloud Top Temperature (CTT) derived product images valid at 1924 UTC (below), the coldest sensed cloud-top temperature values over far southern Lake Michigan were closer (-84ºC with NOAA-20, vs -80ºC with the GOES-16 CTT product).

NOAA-20 Infrared Window (11.45 µm) and GOES-16 Cloud Top Temperature derived product images valid at 1924 UTC [click to enlarge]