Eruption of the Taal Volcano in the Philippines

January 12th, 2020 |

Himawari-8

Himawari-8 “Red” Visible (0.64 µm, left) and “Clean” Infrared Window (10.4 µm, right) images [click to play animation | MP4]

The Taal Volcano erupted in the Philippines around 0850 UTC on 12 January 2020. JMA Himawari-8 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.4 µm) images (above) displayed the volcanic cloud during the initial 3 hours post-eruption. Note the presence of a pronounced “warm wake” (red enhancement) downwind (north) of the summit of Taal — this appeared to be an Above-Anvil Cirrus Plume (AACP), as seen in a toggle between the Visible and Infrared images at 1910 UTC (below).

Himawari-8 "Red" Visible (0.64 µm) and "Clean" Infrared Window (10.4 µm) images at 1910 UTC [click to enlarge]

Himawari-8 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.4 µm) images at 1910 UTC [click to enlarge]

The warmest Himawari-8 10.4 µm brightness temperatures within the Above-Anvil Cirrus Plume were around -60ºC (red enhancement), which corresponded to approximately 21 km on data from 3 rawinsonde sites in the Philippines (Legaspi, Mactan and Laoag) (below).

Plots of rawinsonde data from Legaspi, Mactan and Laoag in the Philippines [click to enlarge]

Plots of rawinsonde data from Legaspi, Mactan and Laoag in the Philippines [click to enlarge]

The TROPOMI detected SO2 at altitude of 20km on 13 January:


A longer animation of Himawari-8 Infrared imagery revealed the intermittent presence of the warm wake feature until about 1400 UTC. The coldest 10.4 µm cloud-top brightness temperature was -89.7ºC.

Himawari-8 "Clean" Infrared Window (10.4 µm) images [click to play animation | MP4]

Himawari-8 “Clean” Infrared Window (10.4 µm) images [click to play animation | MP4]

A large-scale view of Himawari-8 Infrared images (below) showed that the volcanic cloud was advected a great distance north-northeastward.

Himawari-8 "Clean" Infrared Window (10.4 µm) images [click to play animation | MP4]

Himawari-8 “Clean” Infrared Window (10.4 µm) images [click to play animation | MP4]

A toggle between NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images (below) showed the volcanic cloud at 1649 UTC.

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1648 UTC (credit: William Straka, CIMSS) [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1648 UTC (credit: William Straka, CIMSS) [click to enlarge]

In a sequence of Split Window Difference (11-12 µm) images (Terra MODIS, NOAA-20 VIIRS and Suomi NPP VIIRS) from the NOAA/CIMSS Volcanic Cloud Monitoring site (below), there was only a subtle ash signature (blue enhancement) immediately downwind of the Taal summit — due to the large amount of ice within the upper portion of the volcanic cloud, the infrared spectral ash signature was significantly masked.

Split Window Difference (11-12 um) images from Terra MODIS, NOAA-20 VIIRS and Suomi NPP VIIRS [click to enlarge]

Split Window Difference (11-12 µm) images from Terra MODIS, NOAA-20 VIIRS and Suomi NPP VIIRS [click to enlarge]

Of interest was the fact that Manila International Airport (RPLL) reported a thunderstorm at 15 UTC — there was a large amount of lightning produced by Taal’s volcanic cloud.

===== 14 January Update =====

GOES-17 SO2 RGB images [click to play animation | MP4]

GOES-17 SO2 RGB images [click to play animation | MP4]

2 days after the eruption, the leading edge of Taal’s SO2-rich volcanic plume (brighter shades of yellow over areas of cold clouds) began to appear within the far western view of GOES-17 (GOES-West) Full Disk SO2 Red-Green-Blue (RGB) images (above), about 1000 miles southeast of Japan. There were also some thin filaments of SO2 (brighter shades of white over warm ocean areas) moving southward, about 1500 miles west of Hawai’i.

Multi-day outbreak of pyrocumulonimbus clouds across southeastern Australia

December 29th, 2019 |

Himawari-8 Shortwave Infrared (3.9 µm, top) and Longwave Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

Himawari-8 Shortwave Infrared (3.9 µm, top) and Longwave Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

JMA Himawari-8 Shortwave Infrared (3.9 µm) and Longwave Infrared Window (10.4 µm) images (above) showed a large bushfire (dark black to red pixels in the 3.9 µm imagery) in far southeastern Victoria, Australia — which quickly burned its way to the coast and produced 3 distinct pulses of pyrocumulonimbus (pyroCb) clouds on 29 December 2019. To be classified as a pyroCb, the deep convective cloud must be generated by a large/hot fire (in this case, the Cann River fire complex), and eventually exhibit cloud-top 10.4 µm infrared brightness temperatures of -40ºC and colder (assuring the heterogeneous nucleation of all supercooled water droplets to ice crystals).

The coldest cloud-top 10.4 µm infrared brightness temperature was -62.6ºC (darker green pixels) at 1650 UTC. According to rawinsonde data from Melbourne (below), this corresponded to an altitude near 13 km.

Plots of rawinsonde data from Melbourne, Australia [click to enlarge]

Plots of rawinsonde data from Melbourne, Australia [click to enlarge]

The long/narrow thermal anomaly of the hot bushfire — which burned southwestward all the way to the coast — was outlined in dark black pixels on VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP, as viewed using RealEarth (below).

w (11.45 µm) images from NOAA-20 and Suomi NPP [click to enlarge]

VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP [click to enlarge]

===== 30 December Update =====

 Himawari-8 Shortwave Infrared (3.9 µm, top) and Longwave Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

Himawari-8 Shortwave Infrared (3.9 µm, top) and Longwave Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

A Himawari-8 Target Sector was positioned over southeastern Australia beginning at 2312 UTC on 29 December, providing images at 2.5-minute intervals — a comparison of Shortwave Infrared and Longwave Infrared Window imagery (above) revealed the formation of several additional pyroCb clouds as southeastern Victoria bushfires continued to grow in number and size. During the daytime, pyroCb cloud tops will appear warmer (darker gray) than those of conventional thunderstorms in the 3.9 µm imagery, due to enhanced reflection of solar radiation off the smaller ice crystals found in the pyroCb anvil. Development of the multiple deep convective pyroCb clouds on this day may have been aided by forcing for ascent provided by an approaching cold front and mid-tropospheric trough, along with favorable upper-tropospheric jet streak dynamics.

The coldest Himawari-8 cloud-top 10.4 µm brightness temperature on 30 December was -73.15ºC at 13:24:41 UTC (violet pixel near the coast); this was 5ºC colder than the coldest temperature of -68.1ºC  — at an altitude of 15 km — on 12 UTC rawinsonde data from Melbourne (below). During the 12-hour period between the 2 soundings, the coded tropopause ascended from a height of 13.1 km (-63.7ºC) at 00 UTC to 14.2 km (-67.5ºC) at 12 UTC.

Plots of rawinsonde data from Melbourne, Australia at 00 UTC (yellow) and 12 UTC (cyan) [click to enlarge]

Plots of rawinsonde data from Melbourne, Australia at 00 UTC (yellow) and 12 UTC (cyan) [click to enlarge]

In a toggle between VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP is shown (below), a large pyroCb cloud was seen moving eastward away from the bushfires.

VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP [click to enlarge]

VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP [click to enlarge]

===== 31 December Update =====

Suomi NPP VIIRS Day/Night Band, Shortwave Infrared, Near-Infrared & Active Fire Product images at 1455 UTC on 31 December (credit: William Straka, CIMSS) [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm), Shortwave Infrared (3.75 µm and 4.05 µm), Near-Infrared (1.61 µm and 2.25 µm) & Active Fire Product images at 1455 UTC on 31 December (credit: William Straka, CIMSS) [click to enlarge]

Suomi NPP VIIRS Day/Night Band, Shortwave Infrared, Near-Infrared & Active Fire Product images (above) showed nighttime signatures of the widespread bushfires across Victoria and New South Wales at 1455 UTC on 31 December (or 1:55 am local time on 01 January). In the town of Mallacoota, about 4000 people were forced to evacuate their homes and take shelter along the coast (media report). The surface air temperature at Mallacoota Airport briefly increased to 49ºC (120ºF) at 8:00 am local time as the fires approached (below).

A sequence of daily Aqua MODIS True Color RGB images with an overlay of VIIRS Fire Radiative Power showed the fires and smoke during the 29-31 December period (below).

Aqua MODIS True Color RGB images with an overlay of VIIRS Fire Radiative Power [click to enlarge]

Aqua MODIS True Color RGB images with an overlay of VIIRS Fire Radiative Power [click to enlarge]

A multi-day Himawari-8 GeoColor animation covering the period 28 December – 01 January is available here.

Severe turbulence over coastal South Carolina

November 15th, 2019 |

GOES-16 Upper-level Water Vapor (6.2 µm) images, with plots of pilot reports and SIGMET boundaries [click to play animation | MP4]

GOES-16 Upper-level Water Vapor (6.2 µm) images, with pilot reports of turbulence and SIGMET boundaries [click to play animation | MP4]

GOES-16 (GOES-East) Upper-level Water Vapor (6.2 µm) images (above) revealed the presence of elongated W-E oriented billow clouds, many of which exhibited small-scale ripples that were oriented N-S along the billow cloud tops, over coastal areas of South Carolina and North Carolina on 15 November 2019. An initial SIGMET (November 1) was issued covering airspace over Georgia and South Carolina — Severe Turbulence (plotted in red) was reported at 41,000 feet and at 35,000 feet. A second SIGMET (November 2) was later issued covering airspace over South Carolina and North Carolina.

The same GOES-16 Water Vapor images which include isotachs of RAP40 model maximum wind (at any level) are shown below — most of the Moderate to Severe turbulence reports were occurring within the speed gradient along the poleward (left) edge of a SW-NE oriented jet stream flowing parallel to the coast.

GOES-16 Upper-level Water Vapor (6.2 µm) images, with plots of pilot reports, SIGMET boundaries, and isotachs of RAP40 model maximum wind [click to play animation | MP4]

GOES-16 Upper-level Water Vapor (6.2 µm) images, with pilot reports of turbulence, SIGMET boundaries, and isotachs of RAP40 model maximum wind [click to play animation | MP4]

More detailed views of the billow-top ripples were provided by a Terra MODIS Visible image at 1600 UTC, and NOAA-20 VIIRS True Color Red-Green-Blue (RGB) and Infrared images as visualized using RealEarth (below).

Terra MODIS Visible (0.65 µm) image, with plots of pilot reports and SIGMET boundaries [click to enlarge]

Terra MODIS Visible (0.65 µm) image, with pilot reports of turbulence and SIGMET boundaries [click to enlarge]

NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images, with pilot reports of turbulence [click to enlarge]

NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images, with pilot reports of turbulence [click to enlarge]

Lake-effect, river-effect and bay-effect cloud bands producing snowfall

November 13th, 2019 |

GOES-16

GOES-16 “Red” Visible (0.64 µm), “Clean” Infrared Window (10.35 µm) and Day Cloud Phase Distinction RGB images on 07 November [click to play animation | MP4]

During the course of multiple intrusions of arctic air across the Lower 48 states during early November 2019, a variety of lake-effect, river-effect and bay-effect cloud features were generated — many of which produced varying intensities of snowfall. GOES-16 (GOES-East) “Red” Visible (0.64 µm), “Clean:” Infrared Window (10.35 µm) and Day Cloud Phase Distinction Red-Green-Blue (RGB) images on 07 November (above) showed lake-effect clouds streaming south-southeastward across Lake Superior. The Day Cloud Phase Distinction RGB images (in tandem with the Infrared images) helped to highlight which cloud features had glaciated and were therefore more capable of producing moderate to heavy lake-effect snow; the dominant band yielded 5-10 inches of snowfall in the central part of northern Michigan.

On 11 November, GOES-16 Nighttime Microphysics RGB images (below) displayed lake-effect clouds originating from the still-unfrozen waters of Fort Peck Lake in northeastern Montana — these clouds did produce a brief period of light snowfall downstream at Glendive (KGDV). On this particular morning, the lowest temperature in the US occurred in north-central Montana, with -30ºF reported north of Rudyard.

GOES-16 Nighttime Cloud Phase Distinction RGB images on 11 November [click to play animation | MP4]

GOES-16 Nighttime Microphysics RGB images on 11 November [click to play animation | MP4]

On 12 November, cold air moving southward across the Lower Mississippi Valley produced horizontal convective roll clouds which were evident in GOES-16 Nighttime Microphysics RGB and subsequent Visible images after sunrise (below) — one of these narrow cloud bands was likely enhanced by latent heat fluxes as it passed over the comparatively-warm waters of the Mississippi River, and produced accumulating snowfall in downtown Memphis. Note that since Memphis International Airport KMEM was located just east of the cloud band, no accumulating snow was reported there (only a brief snow flurry around 1430 UTC).

GOES-16 Nighttime Microphysics RGB and "Red" Visible (0.64 µm) images on 12 November [click to play animation | MP4]

GOES-16 Nighttime Microphysics RGB and “Red” Visible (0.64 µm) images on 12 November [click to play animation | MP4]

Aqua MODIS Sea Surface Temperature values along parts of the Mississippi River were as warm as the mid-40s F (below).

MODIS Sea Surface Temperature product at 1848 UTC on 12 November; rivers are plotted in red [click to enlarge]

Aqua MODIS Sea Surface Temperature product at 1848 UTC on 12 November; rivers are plotted in red [click to enlarge]


On 13 November, as the cold air was moving off the US East Coast, GOES-16 Infrared images (below) revealed bay-effect cloud plumes which developed over Chesapeake Bay and Delaware Bay — the Chesapeake Bay plume produced brief periods of light snow at Oceana Naval Air Station in Virginia Beach KNTU from 06-10 UTC (and possibly contributed to snowfall farther south at Elizabeth City, North Carolina KECG).

GOES-16 "Clean" Infrared Window (10.35 µm) images on 12 November [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images on 12 November [click to play animation | MP4]

Terra MODIS Sea Surface Temperature values in Chesapeake Bay and Delaware Bay were in the lower to middle 50s F where the bay-effect cloud plumes were originating (below).

Terra MODIS Sea Surface Temperature product and Visible (0.65 µm) image at 1613 UTC [click to enlarge]

Terra MODIS Sea Surface Temperature product and Visible (0.65 µm) image at 1613 UTC [click to enlarge]