Severe thunderstorms in North Dakota and South Dakota

July 4th, 2018 |

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with SPC storm reports plotted in blue [click to play MP4 animation]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.3 µm) images (above) showed the merger of two Mesoscale Convective Systems over North Dakota and South Dakota during the nighttime (pre-sunrise) hours on 04 July 2018. In addition to hail of 1.00-2.00 inches in diameter, these thunderstorms produced widespread damaging winds up to 95 mph in north-central South Dakota (SPC storm reports).

Nighttime comparisons of VIIRS instrument Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) imagery from the Suomi NPP and NOAA-20 satellites are shown below (courtesy of William Straka, CIMSS). With illumination from the Moon (which was in the Waning Gibbous phase, at 68% of Full), the “visible image at night” capability of the Day/Night Band was demonstrated; numerous bright lighting streaks could also be seen, with many in the vicinity of the cold overshooting tops that were evident on Infrared imagery. The Infrared images also revealed cloud-top gravity waves which were propagating radially outward away from the primary clusters of cold overshooting tops.

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

County Fire in central California

July 1st, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images, with airport identifiers plotted in yellow [click to play animation | MP4]

The County Fire began burning in central California (northwest of Sacramento) around 2112 UTC or 2:12 pm local time on 30 June 2018 — GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) showed the smoke plume and thermal anomaly or “hot spot” (dark black to red pixels) of the fire during its initial 6.5 hours. Other features of interest in the imagery included reflection of sunlight from solar panel farms as seen here and here, as well as sun glint off the waters of the Sacramento River and the Sacramento-San Joaquin River Delta as seen here.

During the subsequent overnight hours, the thermal signature exhibited on GOES-16 Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images (below) revealed the rapid southward spread of the fire along the Napa/Yolo county line — the fire began in far western Yolo County, and eventually moved into far eastern Napa County. The smaller, less intense fire signature seen just to the northwest was that of the Pawnee Fire.

GOES-16 Near-Infrared

GOES-16 Near-Infrared “Snow/Ice” (1.61 µm, left), Near-Infrared “Cloud Particle Size” (2.24 µm, center) and Shortwave Infrared (3.9 µm, right) images, with airport identifiers plotted in yellow and Napa/Yolo County outlines plotted in blue [click to play animation | MP4]

A toggle between Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images (below) showed the thermal anomaly and bright glow of the County fire at 1043 UTC or 3:43 am local time. Due to ample illumination from the Moon (in the Waning Gibbous phase, at 90% of Full), the smoke plume could be seen drifting southwest over the adjacent waters of the Pacific Ocean — note the shadow cast by the smoke plume upon the fog/stratus deck immediately off the coast.

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images, with surface reports plotted in cyan [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images, with surface reports plotted in cyan [click to enlarge]

A toggle between consecutive Suomi NPP VIIRS Day/Night Band (0.7 µm) images (below) showed the change in location of the smoke plume during the ~1 hour and 40 minutes separating the 2 satellite overpasses. The region was on the far western edge of the earlier swath. These images demonstrate the “visible image at night” capability of the VIIRS Day/Night Band.

Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]

The 00 UTC rawinsonde data from nearby Oakland (below) showed northeasterly winds at altitudes of 1500-2800 meters or 4900-9200 feet.

Plots of rawinsonde data from Oakland, California [click to enlarge]

Plots of rawinsonde data from Oakland, California [click to enlarge]

During the late morning and early afternoon of 01 July, the fire burn scar could be seen beneath the smoke plume on 250-meter resolution Terra and Aqua MODIS False Color Red-Green-Blue (RGB) images viewed using RealEarth (below).

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

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

Aqua MODIS True Color and False Color RGB images [click to enlarge]

Aqua MODIS True Color and False Color RGB images [click to enlarge]

===== 03 July Update =====

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

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

A 30-meter resolution Landsat-8 False Color RGB image (above) showed the areal extent of the County Fire burn scar on the morning of 03 July. Pink-colored pixels indicated hot signatures of actively-burning fires. The morning Incident Report listed the fire size at 70,000 acres and 5% containment.

Derecho from the Midwest to the Mid-South

June 28th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with SPC storm reports plotted in red [click to play MP4 animation]

GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed a large Mesoscale Convective System (MCS) which produced a long-lived path of large hail and damaging winds from eastern Nebraska to western Tennessee on 28 June 2018. The length and duration of damaging wind events (SPC storm reports) qualified this event as a derecho.

The corresponding GOES-16 “Clean” Infrared Window (10.3 µm) images (below) revealed cold cloud-top infrared brightness temperatures that occasionally reached -80ºC (violet enhancement).

GOES-16 "Clean" Infrared Window (10.3 µm) images, with SPC storm reports plotted in cyan [click to play MP4 animation]

GOES-16 “Clean” Infrared Window (10.3 µm) images, with SPC storm reports plotted in cyan [click to play MP4 animation]

A closer look at the MCS using 375-meter resolution Suomi NPP VIIRS Infrared Window (11.45 µm) images (below) showed cloud-top gravity waves on the 1844 UTC image, propagating radially outward from the primary area of overshooting tops; cloud-top infrared brightness temperatures were as cold as -86ºC (violet enhancement).

Suomi NPP VIIRS Infrared Window (11.45 µm) images, with SPC storm reports plotted during the 3 hours preceding the 1844 UTC image [click to enlarge]

Suomi NPP VIIRS Infrared Window (11.45 µm) images, with plots of SPC storm reports during the 3 hours preceding the 1844 UTC image [click to enlarge]

River valley fog in the Upper Midwest

June 28th, 2018 |

NOAA-20 VIIRS Day/Night Band (0.7 µm) and

NOAA-20 VIIRS Day/Night Band (0.7 µm) and “Fog Product” Infrared Brightness Temperature Difference (11.0 – 3.7 µm) images, with plots of Ceiling and Visibility [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and "Fog Product" Infrared Brightness Temperature Difference (11.0 - 3.7 µm) images, with plots of Ceiling and Visibility [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and “Fog Product” Infrared Brightness Temperature Difference (11.0 – 3.7 µm) images, with plots of Ceiling and Visibility [click to enlarge]

Comparisons of NOAA-20 and Suomi NPP VIIRS Day/Night Band (0.7 µm) and “Fog Product” Infrared Brightness Temperature Difference images (above) showed the nighttime formation of river valley fog in parts of the Mississippi River and its tributaries in Minnesota, Wisconsin and Iowa on 28 June 2018.  Due to ample illumination from the Full Moon, the Day/Night Band provided a “visible image at night” with better fog detail in some areas than was seen using the traditional “Fog Product”. (Note: the NOAA-20 images are incorrectly labeled as Suomi NPP)

A toggle between NOAA-20 and Suomi NPP VIIRS Day/Night Band images acquired by the SSEC Direct Broadcast ground station (below) revealed increased fog formation over portions of the Mississippi River between Rochester MN and Madison WI during the 52 minutes separating the two images.

NOAA-20 and Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]

NOAA-20 and Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]

During the subsequent daylight hours, GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (below) showed that the fog dissipated by 15 UTC or 10am local time.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with hourly plots of surface weather type [click to play animation | MP4]

GOES-16 Natural Color Red-Green-Blue (RGB) images are shown below.

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

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