Hat tip to NWS Buffalo NY forecasters Jon Hitchcock and David Zaff for letting us know about a number of aircraft dissipation trails (also known as “distrails” or “hole punch clouds”) over the Lake Ontario region on 04 November 2013. A series of McIDAS images of 1-km resolution GOES-13 Visible (0.63 µm) data (above) showed these features as they drifted eastward during the day.

A comparison of AWIPS II images of 375-meter resolution Suomi NPP VIIRS Visible (0.64 µm) visible and the corresponding False Color “Snow Cloud Discrimination” Red-Green-Blue (RGB) at 18:17 UTC (below) indicated that the cloud layer penetrated by aircraft was composed of supercooled water droplets (which appear as brighter shades of white on the RGB image) — but the particles in the aircraft exhaust acted as ice nuclei and caused the cloud to glaciate (ice crystal clouds appear as varying shades of red on the RGB image).

AWIPS images of the POES AVHRR CLAVR-x Cloud Type product confirmed that the cloud layer over the Lake Ontario region was a supercooled water droplet cloud (green color), with the Cloud Top Height product indicating tops in the 7-9 km range (below). However, higher-altitude cirrus clouds were beginning to overspread the region from the west (Cirrus=orange; Thick Ice=yellow; Overlap=violet).

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A rare “hybrid” solar eclipse occurred on 03 November 2013 (photos), which began over the western Atlantic Ocean as an annular eclipse and transitioned into a full total solar eclipse for observers along the narrow path of totality in the far eastern Atlantic and over parts of Africa (map of eclipse path). The Lunar Umbra (or solar eclipse shadow) could be seen tracking rapidly southeastward across the Atlantic Ocean on EUMETSAT Meteosat-10 0.635 µm visible channel images from 10:45-14:30 UTC (above; click image to play animation).

The dark solar eclipse shadow could also be seen near the edge of the Full Disk scan of the GOES-13 satellite at 11:45 UTC, just south and southwest of the Cape Verde Islands (below). Since the current generation of GOES only perform a full disk scan once every 3 hours,  the eclipse shadow could not be followed in time as it was using the 15-minute interval images from Meteosat-10.

With the next-generation GOES-R series, a full disk scan will occur once every 5 minutes. As a part of the GOES-14 Super Rapid Scan for GOES-R (SRSOR) testing, full disk scans were performed every 30 minutes on 14 September 2012.

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Sting jets are wind maxima near the end of bent-back fronts in cases of strong cyclones. As noted earlier on this blog, they can acquire a characteristic look in water vapor imagery, vaguely reminiscent of a scorpion’s stinger. In addition, strongly sinking air around the jet, usually associated with both a tropopause fold and a maximum in ozone, is manifest as a warm (dry) patch in the water vapor (WV) imagery. In the animation above, the sting jet is apparent moving across northern Denmark into southern Sweden between 1500 and 1800 UTC. This is in association with the ‘St. Jude’ storm that killed more than a dozen across northern Europe (Reuters news story).

The strong sinking near a sting jet can transport momentum down to the surface. You should therefore expect to see strong surface wind gusts near the water vapor satellite signature, and that was the case on October 28, as shown below.

Suomi/NPP viewed this storm early in the day on 28 October. The toggle between the VIIRS Day/Night Band and the 11.45 µm IR data, below, shows a developing baroclinic leaf over the British Isles.

A comparison of Aqua MODIS 0.65 µm visible, 11.0 µm IR, and 6.7 µm water vapor channel images visualized using the SSEC Web map Server (below; courtesy of Russ Dengel and Kathy Strabala, SSEC) showed the storm at 12:14 UTC on 28 October. The warm/dry signature of strongly-subsiding middle to lower tropospheric air was particularly evident on the water vapor image (yellow to orange color enhancement) as it was beginning to move eastward over Denmark.

For additional satellite images of this event, see the EUMETSAT Image Library and the Wide World of SPoRT.

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As a large upper-level trough was deepening and moving inland across the western US on 28 October 2013, strong winds interacting with the rugged terrain of the Southwest produced widespread areas of mountain waves, as revealed on McIDAS images of 4-km resolution GOES-13 6.5 µm water vapor data (above; click image to play animation). The fast speed of the animation revealed the non-stationary, “fluid motion” of some of the mountain wave features (especially over northeastern Arizona) — perhaps a clue that they might be associated with turbulence that was of moderate or greater intensity. In general, mountain waves that are quasi-stationary (and non-interfering) do not seem to produce more than light turbulence.

AWIPS images of composites of GOES-15 (GOES-West) and GOES-13 (GOES-East) 6.5 µm water vapor channel data with pilot reports of turbulence (below; click image to play animation) showed numerous reports of moderate to severe turbulence at a wide range of altitudes. In fact, there was even a relatively rare occurrence of a pilot report of Extreme turbulence at 18:01 UTC over far northwestern Arizona (at an altitude of 41,000 feet). Not far to the north, there was also a report of Severe turbulence at 23,000 feet over southwestern Utah.

An AWIPS comparison of 1-km resolution MODIS 0.65 µm visible channel and 6.7 µm water vapor channel images at 20:19 UTC (above) showed that while some of the mountain wave features were at least partially marked by roll clouds on the visible image, many of the mountain waves were occurring in clear air.

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