Eruption of the Ubinas volcano in southern Peru

July 19th, 2019 |

GOES-16 Ash, SO2 and CIMSS Natural Color RGB images [click to play animation | MP4]

GOES-16 Ash, SO2 and CIMSS Natural Color RGB images [click to play animation | MP4]

A sequence of GOES-16 (GOES-East) Ash, SO2 and CIMSS Natural Color Red-Green-Blue (RGB) images (above) showed the volcanic cloud following an eruption of Ubinas in southern Peru on 19 July 2019. The volcanic plume was rich in both ash and SO2.

A plot of surface data from La Paz, Bolivia (below) indicated that the visibility dropped to 3 miles around 16 UTC as the volcanic cloud was drifting over that area.

Time series of surface data from La Paz, Bolivia [click to enlarge]

Time series of surface data from La Paz, Bolivia [click to enlarge]

Terra MODIS Ash Probability, Ash Loading, Ash Height and Ash Effective Radius from the NOAA/CIMSS Volcanic Cloud Monitoring site (below) confirmed the high amounts of ash loading (of generally small ash particles) — with maximum retrieved ash height values in the 18-20 k range.

Terra MODIS Ash Probability, Ash Loading, Ash Height and Ash Effective Radius at 1440 UTC [click to enlarge]

Terra MODIS Ash Probability, Ash Loading, Ash Height and Ash Effective Radius at 1440 UTC [click to enlarge]

Elevated NO2 signatures over the Northeast US

July 19th, 2019 |

TROPOMI NO2 concentration [click to enlarge]

TROPOMI NO2 concentration, courtesy of Bob Carp, SSEC [click to enlarge]

High temperatures (along with high dewpoints) prompted the issuance of Excessive Heat Warnings across much of the Northeast US on 19 July 2019. Under such conditions, surface NO2 concentrations in densely-populated urban areas often become elevated (primarily driven by emissions from motor vehicle exhaust, along with secondary sources such as coal-fired power plants and manufacturing / food processing industrial sources) — the high temperatures accelerate chemical reactions that form pollutants. The TROPOMI instrument detected plumes of elevated NO2 extending downwind (to the northeast) of major cities such as Philadelphia, New York City and Boston (above). The data are displayed using McIDAS-V.

A closer view centered on New York City is shown below.

TROPOMI NO2 concentration [click to enlarge]

TROPOMI NO2 concentration, courtesy of Bob Carp, SSEC [click to enlarge]

The Aqua MODIS Land Surface Temperature product around that time (below) revealed LST values in the 100-110ºF range across the New York City and Boston areas, where the daily maximum surface air temperatures were 95ºF and 93ªF, respectively.

Aqua MODIS Land Surface Temperature, with plots of daily maximum surface air temperatures [click to enlarge]

Aqua MODIS Land Surface Temperature, with plots of daily maximum surface air temperatures [click to enlarge]

Tropical Storm Barry

July 11th, 2019 |

GOES-16 "Red" Visible (0.64 µm) and "Clean" Infrared Window (10.35 µm) images, with plots of buoy and ship reports [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images, with plots of buoy and ship reports [click to play MP4 animation]

Tropical Storm Barry formed in the far northern Gulf of Mexico on 11 July 2019 — 1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) displayed increasing convection associated with the tropical cyclone. The coldest cloud-top infrared brightness temperatures were -86ºC.

As was seen in an animation of GOES-16 Infrared imagery from the CIMSS Tropical Cyclones site (below), Barry was in an environment of low deep-layer wind shear — a factor that was favorable for further intensification.

GOES-16 Infrared (11.2 µm) images, with contours of deep-layer wind shear [click to enlarge]

GOES-16 Infrared (11.2 µm) images, with contours of deep-layer wind shear [click to enlarge]

===== 12 July Update =====

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play animation | MP4]

1-minute GOES-16 Visible images (above) revealed a mesovortex that was rotating counter-clockwise around the low-level circulation center of Barry, which was approaching the coast of Louisiana on 12 July. Note that the METAR site located immediately east of the mesovortex around 17 UTC — KMDJ, Mississippi Canyon Oil Platform — had a wind gust of 73 knots or 84 mph around that time (and later had a wind gust to 90 mph at 2135 UTC or 4:35 PM CDT)

The corresponding GOES-16 Infrared images (below) showed that deep convection remained to the south of the center of Barry.

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

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

===== 17 July Update =====

Aqua MODIS Sea Surface Temperature product [click to enlarge]

Aqua MODIS Sea Surface Temperature product on 09 July [click to enlarge]

An Aqua MODIS Sea Surface Temperature image 2 days prior to the formation of Tropical Storm Barry (above) showed SST values in the upper 80s to low 90s F (darker shades of orange to red) in the northern Gulf of Mexico just south of Louisiana.

8 days later, a Terra MODIS SST image (below) revealed values predominantly in the lower to middle 80s F (green to yellow enhancement) — the slow movement of Barry as it eventually reached hurricane intensity just prior to landfall induced an upwelling of cooler sub-surface water over that area.

Terra MODIS Sea Surface Temperature product on 17 July [click to enlarge]

Terra MODIS Sea Surface Temperature product on 17 July [click to enlarge]

Severe turbulence southwest of Hawai’i

July 11th, 2019 |

GOES-17 Upper-level Water Vapor images, with pilot reports of turbulence [click to play animation | MP4]

GOES-17 Upper-level Water Vapor (6.2 µm) images, with pilot reports of turbulence [click to play animation | MP4]

An Air Canada flight encountered severe turbulence southwest of Hawai’i on 11 July 2019, which injured 37 passengers (media report 1 | media report 2 | pilot report text | pilot report location | flight path | flight data). GOES-17 (GOES-West)  Upper-level Water Vapor (6.2 µm) images (above) and Mid-level Water Vapor (6.9 µm) images (below) revealed subtle gravity waves propagating westward from clusters of thunderstorms located near 160º W longitude. In addition, a small and short-lived thunderstorm developed just north of the turbulence event, which also produced subtle gravity waves (those waves could have interfered with the other waves emanating from the larger storms to the east) — and an even smaller, shorter-lived convective cell developed very near to and right around the time of the 1411 UTC turbulence encounter.

Full-bit-depth images created using geo2grid are also available: 6.2 µm | 6.9 µm.

GOES-17 Mid-level Water Vapor (6.9 µm) images, with pilot reports of turbulence [click to play animation | MP4]

GOES-17 Mid-level Water Vapor (6.9 µm) images, with pilot reports of turbulence [click to play animation | MP4]