GOES-16 data posted on this page are preliminary, non-operational and are undergoing testing.

Stratus and Fog formed over the valleys of Kentucky (and in surrounding states) early on 18 October 2017 (It was there on 17 October as well). When was the fog first obvious from Satellite imagery? It very much depends on the spatial resolution of the Satellite viewing the scene. The Brightness Temperature Difference field (10.3 µm – 3.9 µm) from GOES-16, shown above, can be used to identify regions of stratus clouds that are made up of water droplets. Carefully examine the animation; the time when fog is definitively present over valleys of eastern Kentucky (around 84º W Longitude) is around 0327 UTC.

GOES-16 has 2-km resolution (at the sub-satellite point — 89.5º W Longitude during GOES-16 Check-out); this is superior to GOES-13’s nominal 4-km resolution at the subpoint (75º West Longitude). The GOES-13 Brightness Temperature Difference Field (10.7 µm – 3.9 µm) at 0330 UTC shows no distinct indication of Fog/Stratus over eastern Kentucky. A series of animations of the GOES-13 Brightness Temperature Difference field, from 0215-0345 UTC, from 0415-0500, from 0545-0700 and from 0700-0815 suggest GOES-13 identified the region of fog about 4 hours after GOES-16, at 0730 UTC.

The GOES-13 vs. GOES-16 toggle below, from 0700 UTC on 18 October 2017, shows how the resolution improvement with GOES-16 facilitates earlier detection of fog and stratus as it develops overnight.

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After reaching Category 3 intensity over the eastern Atlantic Ocean on 14 October, Hurricane Ophelia (storm track) rapidly underwent transition to an extratropical storm which eventually spread high winds across much of Ireland and the United Kingdom on 16 October 2017. EUMETSAT Meteosat-10 upper-level Water Vapor (6.25 µm) (above) and lower-level Water Vapor (7.35 µm) images (below) revealed the familiar “scorpion tail” signature of a sting jet (reference). Hourly wind gusts (in knots) from primary reporting stations are plotted in red.

Two sites with notable wind gusts were Cork, Ireland (67 knots at 0930 UTC) and Valley, UK (70 knots at 1500 UT), shown below. In fact, a wind gust of 103 knots (119 mph or 191 km/hour) was reported at the Fastnet Rock Lighthouse off the southwest coast of Ireland.

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In a toggle between Terra MODIS (overpass time around 1159 UTC) and Aqua MODIS (overpass time around 1345 UTC) true-color Red-Green-Blue (RGB) imagery (above), a somewhat hazy appearance was seen over the Irish Sea on the Terra MODIS image. This was due to an airborne plume of sand from the Sahara Desert (UK Met Office story).

In fact, blowing sand was observed about 3 hours later at Isle of Man, from 1520-1620 UTC — during that time period their surface winds gusted to 68 knots (78 mph), and surface visibility was reduced to 2.2 miles (below).

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Hurricane Ophelia — the record-tying 10th consecutive Atlantic basin hurricane of the 2017 season — reached a satellite-estimated Category 3 intensity at 15 UTC on 14 October 2017. GOES-13 (GOES-East) Visible (0.63 µm) and Infrared Window (10.7 µm) images (above) showed a well-defined circular eye as the storm moved well south of the Azores. The tweet below underscores the unusual nature of the intensity and location of Ophelia (which also occurred over unusually-cold waters).

#Ophelia has shattered the record for northeastern-most forming Cat 3 in the Atlantic and is the easternmost overall. League of its own. pic.twitter.com/sZrHap5z1f

— Brenden Moses (@Cyclonebiskit) October 14, 2017

A DMSP-17 SSMIS Microwave (85 GHz) image (below) also revealed a circular eye structure.

One factor that might have aided this increase of intensity was the recent passage of Ophelia through an environment of higher Maximum Potential Intensity (reference), where maximum wind speed values of 100 knots resided (below).

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GOES-16 data posted on this page are preliminary, non-operational and are undergoing testing.

GOES-16 provides many tools to the Operational Meteorologist, and to National Weather Service Incident Meteorologists (IMETs), to monitor fires when they occur, such as those over Napa and Sonoma Counties in California (Blog Post). Visible (0.64 µm) and Shortwave Infrared (3.9 µm) channels, above and below, respectively, are available routinely at 5-minute intervals over the Continental United States. During daytime, the Visible Imagery is useful for highlighting smoke palls and for alerting meteorologists to any wind changes. The Shortwave Infrared has long been used to detect fires; the shortwave infrared channel on GOES-16 can detect hotter and smaller fires than previous GOES Satellites because of improved spatial resolution and improved bit depth in the imagery.

GOES-16 Channels can be combined to create Red Green Blue (RGB) Composites that also help identify fires qualitatively. The Fire RGB, below, combines the shortwave IR (3.9 µm) with the 2.2 µm and 1.6 µm channels; as fires get warmer, radiation is emitted at shorter and shorter wavelengths. When this RGB shows white values, you can be certain that the fire is very hot. At some times in the RGB animation, the 3.9 µm imagery is missing where the fire is exceptionally hot, meaning the ‘red’ component of the RGB has no value, and the RGB acquires a blue and green hue.

The Fire Temperature RGB like the visible imagery shown above offer qualitative information about fire. More quantitative information is available in GOES-16 Baseline Products that are an extension and refinement of the WF-ABBA products available for GOES-13 and GOES-15 (and other satellites). Fire-related products for GOES-16 include Fire Area and Fire Temperature, shown below. The products give the size of the fire within the pixel, and its temperature. These products are valuable in quickly evolving fires to monitor how things change, and the products are available every 5 minutes.

Finally, GOES-16 has 1-minute Mesoscale Sectors that can be used to closely monitor quickly-evolving fire situations. The 3.9 µm shortwave infrared and Fire RGB images are shown below for a two-hour period. There can be significant changes to a fire in 1 minute, as was seen in this Blog Post! Note again that missing points in the 3.9 µm imagery will show up as green or blue regions in the RGB.

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