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.

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]

Undular bore in the southern High Plains

July 10th, 2019 |

GOES-16

GOES-16 “Red” Visible (0.64 µm), Low-level Water Vapor (7.3 µm), Mid-level Water Vapor (6.9 µm) and Upper-level Water Vapor (6.2 µm) images [click to play animation | MP4]

GOES-16 (GOES-East) “Red” Visible (0.64 µm), Low-level Water Vapor (7.3 µm), Mid-level Water Vapor (6.9 µm) and Upper-level Water Vapor (6.2 µm) images (above) showed the southward propagation of an undular bore across Kansas, Oklahoma and Texas on 10 July 2019. This feature appeared to play a role in convective initiation over the Texas Panhandle — and this thunderstorm produced hail and strong winds (SPC storm reports).

GOES-17 HBT Flush

July 10th, 2019 |

GOES-17 "Red Visible (0.64 µm) images [click to play animation | MP4]

GOES-17 “Red Visible (0.64 µm) images [click to play animation | MP4]

Approximately once every 239 days, a HBT (Hydrazine Bipropellant Thruster) Flush is performed on GOES-R series satellites — this flushing burn limits the build-up of ferric nitrate in the HBT valves. Following a GOES-17 (GOES-West) HBT Flush that was conducted on 10 July 2019, a navigation offset of about 145 km was seen in 3 consecutive PACUS sector scans and in 2 consecutive Full Disk scans (immediately after the 10-minute image outage during the flush procedure) — a 5-minute PACUS sector view of Baja California using “Red” Visible (0.64 µm) images is shown above, and a 10-minute Full Disk sector view of thermal anomalies associated with wildfires in Alaska using Shortwave Infrared (3.9 µm) images is shown below.

GOES-17 Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

GOES-17 Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

Additional information on the HBT can be found in the GOES-R Series Data Book.