GOES-15 (GOES-West) Water Vapor (6.5 µm) images (above) showed the southeastward migration of an upper-level low across the North Slope and the eastern Brooks Range of Alaska during the 21 June – 22 June 2016 period. A potential vorticity (PV) anomaly was associated with this disturbance, which brought the dynamic tropopause — taken to be the pressure of the PV 1.5 surface — downward to below the 600 hPa pressure level over northern Alaska. Several inches of snow were forecast to fall in higher elevations of the eastern portion of the Brooks Range.

With the very large satellite viewing angle (or “zenith angle”) associated with GOES-15 imagery over Alaska  — which turns out to be 73.8 degrees for Fairbanks — the altitude of the peak of the Imager 6.5 µm water vapor weighting function (below) was shifted to higher altitudes (in this case, calculated using rawinsonde data from 12 UTC on 22 June, near the 300 hPa pressure level).

The ABI instrument on GOES-R will have 3 water vapor bands, roughly comparable to the 3 water vapor bands on the GOES-15 Sounder — the weighting functions for those 3 GOES-15 Sounder water vapor bands (calculated using the same Fairbanks rawinsonde data) are shown below. Assuming a similar spatial resolution as the Imager, the GOES-15 Sounder bands 11 (7.0 µm, green) and 12 (7.4 µm, red) would have allowed better sampling and visualization of the lower-altitude portion of this particular storm system. The 3 ABI water vapor bands are nearly identical to those on the Himawari-8 AHI instrument; an example of AHI water vapor imagery over part of Alaska can be seen here.

As the system departed and the clouds began to dissipate on 22 June, GOES-13 Visible (0.63 µm) images (below) did indeed show evidence of bright white snow-covered terrain on the northern slopes and highest elevations of the Brooks Range.

A sequence of 1-km resolution POES AVHRR Visible (0.86 µm) images (below) showed a view of the storm during the 21-22 June period, along with the resultant snow cover on 22 June. However, the snow quickly began to melt as the surface air temperature rebounded into the 50’s and 60’s F at some locations.

The increase in fresh snow cover along the northern slopes and the highest elevations of the central and northeastern Brooks Range — most notably from Anaktuvuk Pass to Fort Yukon to Sagwon — was evident in a comparison of Suomi NPP VIIRS true-color Red/Green/Blue (RGB) images from 17 June and 22 June, as viewed using RealEarth (below). The actual time of the satellite overpass on 22 June was 2134 UTC.

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A nighttime comparison of Suomi NPP VIIRS Day/Night Band (0.7 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images at 0853 UTC on 20 June 2016 (above) revealed 2 key features of the large Cedar Fire that had been burning in eastern Arizona: (1) the fire “hot spot” signature (black to yellow to red pixels) on the Shortwave Infrared image, located about 20 miles southwest of Show Low (KSOW), and (2) an approximately 50-mile-wide pall of dense smoke aloft — illuminated by a nearly-full Moon — that had drifted westward then northwestward during the previous 24 hours and was centered northwest of Prescott (KPRC). Note that there was no signature of this smoke feature on the Infrared Window image, since smoke is effectively transparent to infrared radiation.

During the following afternoon hours, a toggle between 2117 UTC Aqua MODIS Near-Infrared “Cirrus detection” (1.61 µm), Visible (0.65 µm), Infrared Window (11.0 µm) and Topography images (below) showed that the smoke aloft had moved northward during the day and was over far northwestern Arizona and southwestern Utah. On the Visible image, the dense layer of smoke obscured the view of surface features that are normally seen on a cloud-free day, but the edges of the smoke feature were difficult or impossible to identify. However, the smoke feature was quite evident on the Near-Infrared “Cirrus detection” image — due to the fact that this spectral band (which will be on the GOES-R ABI instrument) is useful for detecting features composed of particles that are efficient scatterers of light (such as cirrus cloud ice crystals, airborne dust or volcanic ash, and in this case, smoke). As was seen in the VIIRS example above, there was no signature of the smoke on the Infrared Window image — the cooler (lighter gray) shades seen in that region were a result of higher terrain that exhibited cooler brightness temperatures due to more abundant vegetation.

An animation of GOES-15 (GOES-West) Visible (0.63 µm) images (below) showed the aforementioned Cedar Fire smoke in northwestern Arizona early in the day (highlighted by a favorable forward scattering sun-satellite geometry), and also showed the smaller smoke plume from the Reservoir Fire that had just begun burning northeast of Los Angeles. In addition, the brief appearance of bright white flashes across Southern California and extreme southern Nevada (as seen on the 1800, 1830, 1841 and 1845 UTC images) were a result of reflection of sunlight from large solar panel farms.

 

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GOES-13 Infrared Window (10.7 µm) images (above) showed the development of several rounds of deep convection which moved over parts of southern Wisconsin during the 14 June – 15 June 2016 period; these storms were responsible for heavy rainfall at some locations (NWS Milwaukee summary). As mentioned in a WPC Mesoscale Precipitation Discussion, some of these storms were focused along the nose of a low-level jet that was helping to push a warm frontal boundary (surface analyses) through the region. Moisture was also abundant south of the warm front, with a total precipitable water value of 55.1 mm (2.17 inches) seen in rawinsonde data from Davenport IA.

A timely cloud-free overpass of the Landsat-8 satellite on the morning of 15 June provided a 30-meter resolution false-color image as viewed using RealEarth (above), which showed areas of flooding — water appears as darker shades of blue — in the Black Earth area of western Dane County in southern Wisconsin. A before/after comparison of Landsat-8 images processed using an equation to highlight water as blue (below, courtesy of Shane Hubbard, SSEC/CIMSS) revealed the areas of inundation due to the 14-15 June thunderstorms.

Aerial footage from a drone flight (below) showed vivid images of the flooding along Black Earth Creek.

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During the first 2 weeks of June 1991 the Mount Pinatubo volcano on the island of Luzon in the Philippines began to produce a series of eruptions, culminating in the climactic eruption beginning at 0227 UTC on 15 June. An animation of 5-km resolution GMS-4 Infrared Window (11.5 µm) images (above) spans the period from 1831 UTC on 12 June to 1831 UTC on 16 June, and showed the very large volcanic cloud following the 15 June eruption (the animation pauses at the 0230 UTC image on 15 June — just after the time of the major eruption). Also evident in the imagery was the westward movement of what became Category 3 Typhoon Yunya (known locally in the Philippines as Diding) toward Luzon. A larger-scale version of the animation is available here.

A closer view of the GMS-4 Infrared Window (11.5 µm) images (below) revealed interesting characteristics of the volcanic plume which penetrated the tropopause (which was at an air temperature of around -83º C, according to nearby rawinsonde reports) during the 3-8 hours following the onset of the 0227 UTC eruption. Note the initial appearance of a small area of very warm IR cloud-top IR brightness temperatures (-21.6º C at 0631 UTC, and -25.7º C at 0730 UTC) which then blossomed outward and became a westward-moving stratospheric plume that was notably warmer than the majority of the cold volcanic cloud canopy (which exhibited IR brightness temperatures in the -80º to -90º C range, denoted by the violet to yellow color enhancement).

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A higher-resolution (1.1-km) view of the post-eruption cloud was provided by NOAA-10 AVHRR images at 1034 UTC on 15 June (above). Even though it was just past sunset over the Philippines, the narrow stratospheric plume could be seen towering above the canopy of the main volcanic cloud (the plume was at a high enough altitude — estimated at a maximum of 40 km (reference 1 | reference 2) — to still be illuminated by sunlight). The summit of Pinatubo is located 8.7 miles/14 km west-southwest of what was then Clark Air Force Base (station identifier RPLC). On the 10.8 µm Infrared Window image, cloud-top gravity waves could be seen propagating radially outward from the overshooting top located above the volcano (which exhibited a minimum IR brightness temperature of -86º C, violet color enhancement). Note the much warmer IR brightness temperatures (as warm as -31º C, green color enhancement) associated with the stratospheric plume just off the west coast of Luzon. A closer view is available here.

About 10 hours prior to the climactic eruption, a volcanic ash cloud from one of the earlier eruptions was captured by NOAA-10 AVHRR images at 2329 UTC on 14 June (below). Around this same time it can be seen that Yunya was making landfall as a minimal-intensity typhoon along the eastern coast of Luzon. A closer view is available here.

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