MODIS 0.65 µm visible channel, 11.0 µm IR channel, and 6.7 µm water vapor channel images

A comparison of AWIPS images of 1-km resolution MODIS 0.65 µm visible, 11.0 µm IR, and 6.7 µm water vapor channel data (above) showed a textbook example of a “baroclinic leaf” satellite signature associated with the large storm affecting much of the eastern US on 17 January 2013. The baroclinic leaf represents a region of ascending air that originates at low levels on the warm side of the primary surface cold front (18 UTC surface analysis).

4-km resolution GOES-13 6.5 µm water vapor channel images (below; click image to play animation) showed the development several important satellite signatures: (1) the baroclinic leaf; (2) the primary warm conveyor belt;, (3) the cold conveyor belt (which was helping to produce snow across parts of northern Mississippi and Alabama); and (4) a secondary warm conveyor belt after about 19 UTC. For additional information on conveyor belts, see this blog post from January 2011.

GOES-13 6.5 µm water vapor channel images (click image to play animation)

A McIDAS-V representation of the GOES-13 (GOES-East) water vapor image brightness temperatures as a topographical surface (below; click image to play animation; also available as a QuickTime movie) helps to visualize the descending intrusion of dry air (which exhibited warm brightness temperatures, yellow to orange color enhancement) and the ascending streams of moist air (which exhibited blue to white to green colors)  within the warm conveyor belt and baroclinic leaf structures.

GOES-13 6.5 µm water vapor images (click image to play animation)

Another McIDAS-V visualization (below; click image to play animation) shows the 3-dimensional structure of the various jet streams (cyan isosurface of 50 meters per second or higher winds) and the increasing values and ascending height of moisture (mixing ratio) within the primary warm conveyor belt as the cross section slice is moved from south to north. McIDAS-V images courtesy of Joleen Feltz and Mike Hiley (CIMSS).

GOES-13 water vapor image with Rapid Refresh model fields of wind speed and mixing ratio (click image to play animation)

Early in the day, a SIGMET was issued (below) to outline an area of risk for severe turbulence due to wind shear near the axis of the strong jet stream associated with this developing system.

GOES-13 6.5 µm water vapor image with outline of Turbulence SIGMET and Pilot reports of turbulence

===== 18 January Update =====

A comparison of AWIPS images of Suomi NPP VIIRS 0.64 µm visible channel and the corresponding VIIRS false-color Red/Green/Blue (RGB) image (below) aided in the discrimination of the resulting snow cover from the storm (shades of red) versus clouds (shades of white).

Suomi NPP VIIRS 0.64 µm visible channel and False-color Red/Green/Blue (RGB) images

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Suomi NPP VIIRS 11.45 µm IR images (click image to play animation)

A sequence of AWIPS images of Suomi NPP VIIRS 11.45 µm IR data from 13 January to 15 January 2013 (above; click image to play animation) revealed a great deal of motion of the sea ice in the Arctic Ocean off the north coast of Alaska. Surface stations along the Alaskan coast were reporting strong easterly winds during this time period, with gusts in excess of 40-50 knots — these strong winds were helping to push the sea ice westward. Also evident in the images was the relatively warm signature (cyan to yellow color enhancement) exibited by numerous “cracks” in the sea ice — it is unclear whether these features are simply weaknesses in the thick ice pack, or actual leads of open water.

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GOES-13 0.63 µm visible channel images (click image to play animation)

A Mesolow developed over Lake Superior today and moved rapidly northeast towards Ontario. As the system moved near Pukaskwa, ON (48.6 N, 86.3 W), winds there shifted from northwest at 3 knots at 1800 UTC to northeast at 5 knots at 1900 UTC to west at 7 knots, gusting to 16 knots at 2000 UTC. (An animation of surface plots overlain on the satellite imagery is here). The mesolow seems to have developed as an interaction with the topography on Isle Royale. Lake Surface temperatures are in the mid-30s, as is typical this time of year, and 850-mb temperatures (as measured at International Falls at 1200 UTC) were around -18 C.

GOES-15 0.62 µm visible channel images (click image to play animation)

GOES-West provided an oblique view of the system development, shown above.

Hat tip to the National Weather Service in Marquette Michigan for first alerting us to this system’s presence!

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GOES-15 (left) and GOES-13 (right) 0.63 µm visible channel images (click image to play animation)

McIDAS images of GOES-15 (GOES-West) and GOES-13 (GOES-East) 0.63 µm visible channel data (above; click image to play animation) showed the development of a large area of blowing dust that formed in response to high winds along and in the wake of a strong cold frontal boundary (18 UTC surface analysis) that was moving from eastern Colorado into western Kansas on 11 January 2013. Winds gusted to 56 mph in Burlington, Colorado and gusted to 49 mph in Goodland, Kansas (where the surface visibility was reduced to 1.75 miles by the blowing dust).

A closer view using 375-meter resolution (projected onto a 1-km AWIPS grid) Suomi NPP VIIRS 0.64 µm visible channel and the corresponding false-color Red/Green/Blue (RGB) image at 19:23 UTC or 12:23 PM local time (below) revealed the banded structure of the blowing dust cloud,  which was verified by a photo taken around 19:17 UTC from an aircraft over eastern Colorado by William Straka (CIMSS). Also evident on the VIIRS images was  the presence of a number of aircraft dissipation trails (or “distrails”) and “hole punch clouds” across parts of central and eastern Kansas. The brighter pink color enhancement within the distrails and hole punch clouds indicated the glaciation of supercooled water droplets in those portions of the cloud deck that were penetrated by aircraft.

Suomi NPP VIIRS 0.64 µm visible channel and false-color Red/Green/Blue (RGB) image

In a comparison of a 20:33 UTC (or 1:33 PM local time) MODIS 0.65 µm visible image with the corresponding MODIS 11-12 µm IR brightness temperature difference (below), the most dense areas of blowing dust were highlighted by the lighter cyan colors.

MODIS 0.65 µm visible channel and 11-12 µm IR brightness temperature difference product

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