1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Day Cloud Phase Discrimination RGB images (above) showed the development of a mesovortex over southern Lake Michigan on 12 February 2021. The surface flow supporting the mesovortex formation was well-depicted by hourly RAP40 model output. Note that there was a lack of GOES-16 Visible (Band 2) Derived Motion Winds created for this feature — this was likely due to high clouds drifting over the area, making it difficult for the algorithm to properly identify and track surface or near-surface cloud elements. In the western portion of the lake, a ribbon of ice was evident in the nearshore waters of Wisconsin and Illinois.

The GOES-16 Day Cloud Phase Discrimination RGB images indicated that convective cloud elements near the vortex center were becoming glaciated (as highlighted by brighter shades of green) — and light snow reduced the surface visibility to 2.5 miles at Holland, Michigan (KBIV) as the vortex moved inland. A toggle between GOES-16 Visible and Day Cloud Phase Discrimination RGB images at 1800 UTC is shown below.

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The animation above shows GOES-16 Band 4 (1.38 µm, “Cirrus Channel) Imagery along with GOES-16 Derived Motion Wind vectors and Turbulence observations. Significant and widespread turbulence occurred. Of particular interest is a arced feature that appears in the GOES-16 imagery from northern Mississippi through western Tennessee and into south-central Kentucky.  Turbulence occurs along this feature, where strong downward motion is likely present. Note this raw PIREP, for example, showing a very large vertical change!

UUA /OV RQZ/TM 1801/FL 410/TP C25M/TB SEV CAT/RM + OR - 1000 FT AND +60 KNOTS NO INJURIES NO DAMAGE

The curved structure is also prominent in the GOES-16 Band 8 (6.19 µm, Upper Level Water Vapor) infrared imagery shown below in a rocking animation.  It emerges out of convection along the Gulf Coast and subsequently races to the northeast.  The feature is less obvious in the Band 10 animation, suggesting that it is fairly high in the atmosphere. The 1200 UTC sounding from Jackson MS (link, from this website) shows a strong inversion at 500 mb; this might be the vertical boundary under which this feature is trapped. The weighting function for the Jackson sounding (here, from this site), shows peak values for all three water vapor channels very close to 500 mb.

Note that the arcing feature is apparent first in the upper-level water vapor imagery, then in the lower-level water vapor and cirrus channel imagery.

The mp4 animations below are also available as animated gifs: 6.19 µm, 7.34 µm and 1.38 µm)

GOES-16 6.19 µm (Band 8, “Upper-Level Water Vapor”) Infrared Imagery, 1236 UTC 11 February – 0001 UTC 12 February 2021 (Click to play mp4 animation)

 

GOES-16 7.34 µm (Band 10, “Low-Level Water Vapor”) Infrared Imagery, 1236 UTC 11 February – 0001 UTC 12 February 2021 (Click to play mp4 animation)

GOES-16 1.38 µm (Band 4, “Cirrus Channel”) near-infrared Imagery, 1401 UTC – 2201 UTC 11 February 2021 (Click to play mp4 animation)

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CIMSS scientists have recently upgraded a turbulence detection product that was developed using machine learning, combining Satellite Data, principally GOES-R Band 8 (6.19 µm, a “water vapor” band on GOES-R) and Band 13 (the Clean Window infrared, 10.3 µm) and trained on observations of EDR (Eddy Dissipation Rate). These mappings of Probabilities of Moderate or Greater (MOG) turbulence are available online at this website. How did this product fare on this day of active turbulence.

Animations below show predictions of MOG from 1200 to 2350 UTC on 11 February 2021. Predictions of MOG at 30000-31000 feet, 36000-37000 feet and 40000-41000 feet are shown.  The probability contours are shown on top of a grey-scaled 6.19 µm water vapor image, and observations of turbulence are included.

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Beginning on 06 February 2021, the GOES-15 satellite was brought out of storage for a 14-day period of imaging (as part of its annual checkout activities). On 10 February, a comparison of Water Vapor images from GOES-17 (6.9 µm) and GOES-15 (6.5 µm) showed mountain waves over southeastern Wyoming and central Colorado (above). This comparison helped to highlight some of the improvements in the GOES-R Series, such as

•  improved spatial resolution with ABI Water Vapor (and other infrared) spectral bands — 2 km at sub-satellite point for GOES-17, vs 4 km at sub-satellite point for GOES-15
•  improved temporal resolution — 5-minute image interval for GOES-17, vs 15-minute image interval for GOES-15 (except for 30-minute gaps every 3 hours, during Full Disk scans)
• more stable image navigation

Multi-panel animations of GOES-15 images from the Imager and Sounder instruments are shown below (credit: Tim Schmit, NOAA/ASPB). In addition, there are animations of GOES-15 Visible and Infrared Window images.

GOES-15 data were downloaded, processed and archived by SSEC Satellite Data Services. Real-time GOES-15 imagery is temporarily available here: Imager | Sounder.

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GOES-16 visible animations from the morning of 8 February show ice motion along the south shore of Lake Superior, moving northeastward away from Duluth Harbor, and also east and northeastward to the south of Madeline Island. Winds at this time were from the west or southwest at 15-20 knots as shown below by GOES-16 Derived Motion Wind vectors, and by onshore observations.

An overpass of Metop-A at 1429 UTC provided ASCAT surface scatterometer winds (below) — which were as strong as 22 knots near Wisconsin’s Apostle Islands.

There is a GOES-R Ice Motion level 2 Product as well. However, that product uses cross-correlations between visible (Band 2, 0.64 µm) and infrared (Band 14, 11.2 µm) imagery separated by 24 hours. On 7 February, clouds prevented an unobstructed view of lake ice, so ice motion vectors were not computed for 1200 or 1500 UTC on 8 February.

Thanks to Patrick Ayd, SOO at WFO Duluth, for alerting us to this ice motion case.

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(Why it’s important to know about ice moving along the shore of the Lake)

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