CIMSS Satellite Blog, CIMSS

Severe weather outbreak across the central US

By Scott Bachmeier • 28 March 2020

1-minute Mesoscale Domain Sector GOES- 16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed widespread events of severe weather (SPC Storm Reports) associated with a large occluding low pressure system and its frontal boundaries on 28 March 2020.The corresponding GOES-16 “Clean” Infrared Window (10.35 µm) images are shown below. The coldest cloud-top infrared brightness temperatures were in the... Read More

GOES- 16 “Red” Visible (0.64 µm) images, with time-matched (+/- 4 minutes) SPC Storm Reports plotted in red [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES- 16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed widespread events of severe weather (SPC Storm Reports) associated with a large occluding low pressure system and its frontal boundaries on 28 March 2020.

The corresponding GOES-16 “Clean” Infrared Window (10.35 µm) images are shown below. The coldest cloud-top infrared brightness temperatures were in the -60 to -70ºC range (red to black enhancement). The most significant tornado produced EF-3 damage as it moved through Jonesboro, Arkansas beginning at 2157 UTC.

GOES- 16 "Clean" Infrared Window (10.35 µm) images, with time-matched SPC Storm Reports plotted in purple [click to play animation | MP4]

GOES- 16 “Clean” Infrared Window (10.35 µm) images, with time-matched (+/- 4 minutes) SPC Storm Reports plotted in purple [click to play animation | MP4]

A toggle between a Suomi NPP VIIRS Visible (0.64 µm) image (with plots of available NUCAPS soundings) and the Gridded NUCAPS CAPE values (below) revealed pockets of instability across the lower Mississippi River Valley in advance of the approaching cold front. Due to the presence of dense multi-layer cloudiness across much of Arkansas, there were no successful infrared+microwave (green) NUCAPS profiles available near Jonesboro (KJBR), except for a few microwave-only (yellow) soundings just to the south.

Suomi NPP VIIRS Visible (0.64 µm) image with plots of available NUCAPS soundings + Gridded NUCAPS CAPE [click to enlarge]

A plot of 19 UTC rawinsonde data from Little Rock, Arkansas (below) indicated a CAPE value of 2836 J/kg.

Plot of 19 UTC rawinsonde data from Little Rock, Arkansas [click to enlarge]

Additional imagery of this event is available on the Satellite Liaison Blog.

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High-altitude waves over the Arctic

By Scott Bachmeier • 27 March 2020

GOES-17 (GOES-West) “Ozone” (9.61 µm) images (above) revealed waves propagating northwestward over northern Alaska, northern Yukon and the adjacent Beaufort Sea during the pre-dawn hours on 27 March 2020. That area was too illuminated by either aurora borealis or the rising sun — so Suomi NPP VIIRS Day/Night Band (0.7 µm) imagery could not confirm... Read More

GOES-17 “Ozone” (9.61 µm) images, with rawinsonde sites plotted in yellow [click to play animation | MP4]

GOES-17 (GOES-West) “Ozone” (9.61 µm) images (above) revealed waves propagating northwestward over northern Alaska, northern Yukon and the adjacent Beaufort Sea during the pre-dawn hours on 27 March 2020. That area was too illuminated by either aurora borealis or the rising sun — so Suomi NPP VIIRS Day/Night Band (0.7 µm) imagery could not confirm the presence of mesospheric airglow waves (see this blog post for some examples).

A plot of the GOES-17 “Ozone” spectral band weighting function — calculated using 12 UTC rawinsonde data from Fairbanks, Alaska — showed a peak contribution from within the stratosphere at the 39 hPa pressure level, corresponding to an altitude around 21 km (below).

Plot of GOES-17 “Ozone” (9.61 um) weighting function, calculated using 12 UTC rawinsonde data from Fairbanks, Alaska [click to enlarge]

The curious aspect of these waves was their northwestward propagation — rawinsonde data from 3 sites across the region (below) indicated that the winds aloft within the upper troposphere and throughout the stratosphere were strong northwesterly, which meant the waves were moving against the ambient flow. Lacking a coherent, science-based explanation for these wave features, this blog post earns its place in the “What the heck is this?” category.

Plots of rawinsonde data from Fairbanks, Alaska [click to enlarge]

Plots of rawinsonde data from Utqiagvik (formerly Barrow), Alaska [click to enlarge]

Plots of rawinsonde data from Inuvik, Northwest Territories [click to enlarge]

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Year-long Animations of Visible and Infrared Images

By Scott Lindstrom • 26 March 2020

A previous blog post (here) has shown 1-month animations of true-color visible imagery from geostationary satellites (GOES-16, GOES-17, Himawari-8, Meteosat-11 and others) wherein local noon longitudinal strips are blended together to create a global view. (Imagery courtesy Rick Kohrs, SSEC) (See also this blog post for an explanation). The animation above (Click... Read More

True-color visible imagery global montage from 6 March 2019 – 5 March 2020 (Click to launch containerized YouTube Vide)

A previous blog post (here) has shown 1-month animations of true-color visible imagery from geostationary satellites (GOES-16, GOES-17, Himawari-8, Meteosat-11 and others) wherein local noon longitudinal strips are blended together to create a global view. (Imagery courtesy Rick Kohrs, SSEC) (See also this blog post for an explanation). The animation above (Click it to view a YouTube animation within a container) shows visible true-color imagery for each day from 6 March 2019 through 5 March 2020.

The infrared imagery below combines the ‘clean window’ Band 13 channel on GOES-16 and GOES-17 (10.3 µm on both) with Band 13 on Himawari-8 (10.4 µm) and shows 2019 data at 6-h intervals.

Color-enhanced Window Channel infrared (ABI: 10.3 µm; AHI: 10.4 µm) imagery from 2019 (Click to launch containerized YouTube Vide)

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Anomalously-strong jet stream winds over Colorado

By Scott Bachmeier • 25 March 2020

An anomalously-strong upper tropospheric jet stream was moving over northern Colorado on 25 March 2020 — GOES-16 (GOES-East) Upper-level Water Vapor (6.2 µm) images, with plots of Derived Motion Winds and contours of RUC40 model maximum wind speeds (above) revealed that the highest satellite-tracked Derived Motion Wind speeds just northeast of Grand Junction, Colorado (KGJT)... Read More

GOES-16 Upper-level Water Vapor (6.2 µm) images, with plots of Derived Motion Winds and contours of RUC40 model maximum wind speeds [click to play animation | MP4]

GOES-16 Upper-level Water Vapor (6.2 µm) images, with plots of 6.2 µm Derived Motion Winds and contours of RUC40 model maximum wind speeds [click to play animation | MP4]

An anomalously-strong upper tropospheric jet stream was moving over northern Colorado on 25 March 2020 — GOES-16 (GOES-East) Upper-level Water Vapor (6.2 µm) images, with plots of Derived Motion Winds and contours of RUC40 model maximum wind speeds (above) revealed that the highest satellite-tracked Derived Motion Wind speeds just northeast of Grand Junction, Colorado (KGJT) were 165 knots. RUC40 model Maximum Wind Speed values were also around 165 knots across that area. The strongest wind speeds in 00 UTC rawinsonde data from Grand Junction were 160 knots (below).

Plot of rawinsonde data from Grand Junction, Colorado at 00 UTC on 26 March [click to enlarge]

The 250 hPa GFS model wind speed anomalies (below) were 3-4 sigma above normal over northern Colorado at 00 UTC on 26 March (source).

250 hPa wind speed anomalies at 00 UTC on 26 March [click to enlarge]

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Severe weather outbreak across the central US

High-altitude waves over the Arctic

Year-long Animations of Visible and Infrared Images

Anomalously-strong jet stream winds over Colorado

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