Minor explosive eruption of Kilauea in Hawai’i

May 19th, 2018 |

Himawari-8 Ash Cloud Height product {click to play animation]

Himawari-8 Ash Cloud Height product [click to play animation]

An explosive eruption from the Halema’uma’u crater at the Kilauea summit on the Big Island of Hawai’i occurred around 1550 UTC on 19 May 2018. Using Himawari-8 data, multispectral retrievals of parameters such as Ash Cloud Height (above) and Ash Loading (below) from the NOAA/CIMSS Volcanic Cloud Monitoring site helped to characterize the volcanic ash plume.

Himawari-8 Ash Loading product [click to play animation]

Himawari-8 Ash Loading product [click to play animation]

Later in the day, a Suomi NPP VIIRS True-color Red-Green-Blue (RGB) image viewed using RealEarth (below) showed the hazy signature of volcanic smog or “vog” which had spread out to the south, southwest and west of the Big Island. Light amounts of ash fall were reported downwind of Kilauea.

Suomi NPP VIIRS True-color RGB image [click to enlarge]

Suomi NPP VIIRS True-color RGB image [click to enlarge]

PyroCumulonimbus cloud in Texas

May 11th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, top), Shortwave Infrared (3.9 µm, center) and “Clean” Infrared Window (10.3 µm, bottom) images, with hourly plots of surface reports [click to play MP4 animation]

A large pyroCumulonimbus (pyroCb) cloud developed from the Mallard Fire in the Texas Panhandle on 11 May 2018, aided by warm temperatures and strong winds ahead of an approaching dryline (surface analyses).  1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.3 µm) images (above) showed the large thermal anomaly or “hot spot” (red 3.9 µm pixels) and the rapid development of  the pyroCb cloud beginning shortly after 1900 UTC. Cloud-top infrared brightness temperatures cooled to -60 ºC — the tropopause temperature on the 00 UTC Amarillo sounding — by around 2130 UTC. On the Shortwave Infrared imagery, note the relatively warm (darker gray) appearance of the pyroCb cloud top — a characteristic signature of pyroCb anvils due to enhanced reflection of solar radiation off of smaller cloud-top particles.

4-panel comparisons of Suomi NPP VIIRS Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images at 1936 UTC and 2029 UTC (below) revealed that the maximum differences between 3.74 µm and 11.45 µm cloud-top infrared brightness temperatures — at the same location on the pyroCb anvil — were 86ºC (+26ºC and -59ºC at 1936 UTC) and 91.5ºC (+27.5ºC and -63ºC at 2029 UTC).

Suomi NPP VIIRS Visible (0.64 µm), Near-Infrared

Suomi NPP VIIRS Visible (0.64 µm, upper left), Near-Infrared “Snow/Ice” (1.61 µm, upper right), Shortwave Infrared (3.74 µm, lower left) and Infrared Window (11.45 µm, lower right) images at 1936 UTC and 2029 UTC [click to enlarge]

Lightning was detected from portions of the smoke plume, as well as the core of the pyroCb thunderstorm.

After dark, the thermal signature of the Mallard Fire was also apparent on GOES-16 Near-Infrared “Cloud particle size” (2.24 µm) imagery (below).

GOES-16 Near-Infrared

GOES-16 Near-Infrared “Cloud particle size” (2.24 µm, top), Shortwave Infrared (3.9 µm, center) and “Clean” Infrared Window (10.3 µm, bottom) images, with hourly plots of surface reports [click to play MP4 animation]

===== 12 May Update =====

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

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

In a comparison of 250-meter resolution Terra MODIS True-color and False-color Red-Green-Blue (RGB) images from the MODIS Today site (above), the Mallard Fire burn scar was evident in the False-color. Both images showed a smoke plume from ongoing fire activity, which was drifting northward across the Texas Panhandle.

The corresponding Terra MODIS Land Surface Temperature product (below) indicated that LST values within the burn scar were as high as 137ºF (darker red enhancement), in contrast to values around 100ºF adjacent to the burn scar.

Terra MODIS Land Surface Temperature product [click to enlarge]

Terra MODIS Land Surface Temperature product [click to enlarge]

Severe weather across southern Wisconsin

May 9th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, top) and “Clean” Infrared Window (10.3 µm, bottom) images, with airport identifiers plotted in yellow and SPC storm reports plotted in red [click to play MP4 animation]

Severe weather (SPC | NWS ARX | NWS MKX) occurred across far southern Wisconsin on the afternoon of 09 May 2018, as a surface low moved eastward across the area. 1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (above) provided a view of the isolated thunderstorm that rapidly developed in far southwestern Wisconsin around 1800 UTC. The evolution of overshooting tops was seen in both Visible and Infrared imagery — cloud-top infrared brightness temperatures cooled into the -50 to -60 ºC range (orange to red enhancement). On the Visible imagery, rear inflow feeder bands could be seen on the southwestern flank of the storm leading up to the time that it produced 1.00-inch diameter hail near Madison at 2045 UTC. SPC storm reports are “parallax corrected” so as to be plotted at a height corresponding to the cloud-top features of the parent storm.

A comparison of Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images at 1923 UTC (below) showed the isolated thunderstorm as it was moving into northwestern Dane County. The rear inflow feeder bands were evident, and the minimum cloud-top infrared brightness temperature was -62 ºC.

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images [click to enlarge]

GOES-16 Rayleigh-corrected pseudo true color Red-Green-Blue (RGB) images (below; courtesy of Pete Pokrandt, AOS) showed a large Mesoscale Convective Vortex (MCV) that moved through northern Illinois and Wisconsin during the early morning hours, along with the hazy signature of smoke from agricultural burning in the central Plains (which was being drawn northward across eastern Iowa ahead of the surface cold front).

GOES-16 Rayleigh-corrected RGB images [click to play YouTube video]

GOES-16 Rayleigh-corrected RGB images [click to play YouTube video]

Subtropical cyclone formation off the coast of Chile

May 9th, 2018 |

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with hourly plots of surface weather [click to play MP4 animation]

A very unusual subtropical cyclone formed off the coast of Chile during the 07-08 May 2018 period (Weather Channel | Weather Underground). The system transitioned from a typical cold core baroclinic mid-latitude cyclone to a shallow warm core cyclone with some deep convection around the center of circulation. GOES-16 (GOES-East) “Clean” Infrared Window (10.3 µm) images (above) showed the evolution from 06 May to 09 May. The surface report plotted in the lower right corner of the images is Concepción, Chile.

A Suomi NPP VIIRS True-color Red-Green-Blue (RGB) image viewed using RealEarth (below) depicted the circulation once it had drifted to a position northwest of Santiago, Chile at 1839 UTC on 08 May.

Suomi NPP VIIRS Ttue-color RGB image [click to enlarge]

Suomi NPP VIIRS Ttue-color RGB image [click to enlarge]

The hourly MIMIC Total Precipitable Water product (below) initially showed a long ribbon of subtropical moisture which was being transported ahead of a cold front into the baroclinic low on 05 May — then during the transition to a subtropical low, a small pocket of modest TPW migrated slowly northward  with the surface circulation.

MIMIC Total Precipitable Water product [click to play animation | MP4]

MIMIC Total Precipitable Water product [click to play animation | MP4]