Suomi NPP VIIRS 0.64 µm visible, 3.74 µm shortwve IR, and 11.45 µm IR images

A wide band of multi-layered clouds was oriented southwest-to-northeast along a cold frontal boundary moving through the Ohio River Valley region on 10 December 2012.  On a 1-km resolution Suomi NPP VIIRS 11.45 µm IR image at 17:42 UTC (above), much of this cloud band was topped with cirrus clouds exhibiting IR brightness temperatures in the -50 to -60 C range (orange to red color enhancement), indicating a cloud top height in the 30,000-40,000 foot range (KILM rawinsonde data | KPIT rawinsonde data)– the general cruising altitudes of most aircraft.

It is interesting to note that the Suomi NPP VIIRS 3.74 µm shortwave IR image revealed a large number of contrails across that cloud band — the contrails appeared darker than the background cirrus clouds, due to reflection of solar radiation by smaller ice crystals or by supercooled water droplets. Either the contrails themselves were located above the cirrus cloud deck, or the aircraft were flying through the top portion of the cirrus clouds and altering the microphysics of the cloud ice crystals to make them smaller.

Similar contrails were seen about an hour later on a 1-km resolution MODIS 3.7 µm shortwave IR image (below).

MODIS 0.65 µm visible, 3.7 µm shortwave IR, and 11.0 µm IR images

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

A strong winter storm moved across the Northern Plains and Upper Midwest regions of the US on 09 December 2012, producing widespread heavy snowfall (HPC storm summary) and creating blizzard conditions that closed a number of roads (including portions of Interstates 90 and 29 in eastern South Dakota). AWIPS images of GOES-13 0.63 µm visible channel data (above; click image to play animation) showed the development of a tightly-curved deformation band across Minnesota during the day — much of the heavier snowfall totals occurred beneath the pivot point of this deformation feature.

GOES-13 6.5 µm water vapor channel images (below; click image to play animation) showed the development of a dry slot along the leading edge of the core of a potential vorticity (PV) anomaly (red contours) that was moving northeastward over southern Minnesota. The approach of this PV anomaly was helping to enhance upward vertical velocities, thereby increasing snowfall rates.

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

A northwest-to-southeast oriented vertical cross section using NAM40 model fields at 21 UTC (below) showed that the PV anomaly was lowering the height of the dynamic tropopause (taken to be the pressure of the PV1.5 surface) down to the 525 millibar level over southern Minnesota.

NAM40 vertical cross section

A comparison of 1-km resolution images of MODIS 0.65 µm visible channel, 11.0 µm IR channel, and 6.7 µm water vapor channel data at 19:48 UTC (below) revealed hints of some subtle banding structure over parts of Minnesota and Wisconsin, which was likely helping to enhance snowfall rates over those areas.

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

On the back side of the storm, cold arctic air was being drawn southward across wesern North Dakota and South Dakota — and a comparison of a MODIS 0.65 µm visible image with the corresponding false-color Red/Green/Blue (RGB) image using the 2.1 µm “snow/ice channel” (below) revealed small “river-effect cloud bands” forming (most notably over Lake Sakakawea in North Dakota) as this cold air moved over the still-unfrozen waters of the larger reservoirs of the Missouri River. Deeper snow cover appeared as darker shades of red, in contrast to supercooled cloud features which were brighter shades of white.

MODIS 0.65 µm visible image + False-color Red/Green/Blue (RGB) image

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Suomi NPP VIIRS Day/Night Band composite (global view)

On 05 December 2012 NASA and the NOAA National Geophysical Data Center (NGDC) jointly released a “Black Marble” global composite of night-time Suomi NPP VIIRS 0.7 µm Day/Night Band imagery (collected from multiple cloud-free satellite overpasses in April and October 2012) — the image above shows this dataset visualized using the SSEC Web Map Server. See the NASA news story and the SSEC news story for additional details.

Suomi NPP VIIRS 0.7 µm Day/Night Band composite image (North America)

A closer view of North America is shown above, with a zoomed-in image centered on Madison, Wisconsin shown below.

Suomi NPP VIIRS 0.7 µm Day/Night Band composite image (centered on Madison, WI)

Many examples of the VIIRS Day/Night Band showing a variety of phenomena can be found elsewhere on the CIMSS Satellite Blog.

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

Two features of interest appeared on McIDAS images of GOES-13 0.63 µm visible channel data (above; click image to play animation) on the morning of 05 December 2012: (1) fingers of valley fog across much of Kentucky, which dissipated as daytime heating and boundary layer mixing increased, and (2) a pair of aircraft dissipation trails (or “distrails”) that first appeared north of Sumter (KSSC) and drifted east-northeastward between Florence (KFLO) and Darlington (KUDG). It is likely that these distrails (highlighted with yellow ‘>’ symbols) formed as aircraft heading to or from Columbia, South Carolina (KCAE) passed through the supercooled water droplet cloud layer, causing glaciation and subsequent fallout of the ice crystals to create the elongated clearing lines.

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