2.5-minute rapid scan JMA Himawari-8 Shortwave Infrared (3.9 µm) images (above) showed numerous thermal anomaly (or “hot spot”, darker red to black pixels) signatures of wildfires across southeastern North Korea and northeastern South Korea on 04 April 2019 (media story). The fires were fanned by strong west-southwest winds in the wake of a cold frontal passage associated with an anomalously-deep midlatitude cyclone moving across far northeastern China (surface analyses); winds gusted to 53 knots at Yangyang International Airport (station identifier RKNY) to the south of Sokcho at 09 UTC (below). Standing wave clouds — forming in response to the strong westerly winds — were seen downwind of the mountainous terrain of the eastern Korean Peninsula from 1030-1930 UTC.

Comparisons of VIIRS Day/Night Band (0.7 µm), Near-infrared (1.61 µm and 2.25 µm), Shortwave Infrared (3.75 µm and 4.05 µm) and Infrared Window (11.45 µm) images from NOAA-20 at 1649 UTC and Suomi NPP at 1739 UTC are shown below (courtesy of William Straka, CIMSS). A subtle thermal signature of the largest fires — located between Gangneug and Donghae, and also near Sokcho — was even apparent as darker pixels on the Infrared Window (I-Band 5, 11.45 µm) images. On the Day/Night Band images, note the striking lack of city lights in the southeastern portion of North Korea in these nighttime scenes.

Thermal signatures of the fires were also captured by KMA COMS-1 Shortwave Infrared (3.9 µm) imagery (below), but not as well as with Himawari-8 given the inferior spatial resolution (4 km, vs 2 km for Himawari-8) and image frequency (15 minutes, vs 2.5 minutes with the Himawari-8 Japan Sector).

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed a cluster of deep convection just to the north of the center of a rapidly-intensifying midlatitude cyclone (surface analyses) off the coast of North Carolina on 02 April 2019. In addition, convection was later seen developing along the north-south cloud band marking the leading edge of the cyclone’s cold front. The rapid deepening of this hurricane force low easily met the criteria of a bomb cyclone — its central pressure dropped 20 hPa in just 12 hours (from 1004 hPa at 18 UTC on 02 April to 984 hPa at 06 UTC on 03 April).

The primary convective cluster began to exhibit a large amount of lightning after 1830 UTC, as seen in plots of GOES-16 GLM Groups (below). To the east of this intensifying convection, one ship report at 18 UTC included winds from the east at 50 knots — in addition, a moderate to heavy shower of hail was being reported and their surface visibility was restricted to 1.25 miles (18 UTC surface analysis).

There were several factors pointing to the development of a sting jet with this storm, as discussed here and here. GOES-16 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (below) revealed distinct areas of warming/drying (darker shades of yellow to orange) that possibly highlighted rapidly-descending air associated with a sting jet (for example, on the 1946 UTC images).

After 23 UTC, GOES-16 “Clean” Infrared Window (10.3 µm) images (below) portrayed the formation of a large eye-like feature indicative of a warm seclusion (00 UTC surface analysis). Lightning activity remained very high during that time.

Yesterday’s top long lasting expansive superbolt lightning flash #GOES16 #GLM @NOAASatellites pic.twitter.com/r4kP7vORjO

— Michael J. Peterson (@WeatherArchive) April 4, 2019

As you might imagine, this monster system produced some incredible lightning #GLM #lightningfromspace #GLMTOE pic.twitter.com/diBKAEOJVG

— Scott Rudlosky (@goesglm) April 3, 2019

A comparison between 1-km resolution Terra MODIS Infrared Window (11.0 µm) imagery at 0237 UTC with an Aqua MODIS Sea Surface Temperature product at 1755 UTC on the following afternoon (below) showed that the storm intensified and formed the large eye-like feature over the northern portion of the axis of warmest Gulf Stream water (where SST values were in the 70-76ºF range).

With a nighttime overpass of the NOAA-20 satellite at 0651 UTC, the eye-like feature was apparent in VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images (below). Although the Moon was in the Waning Crescent phase (at only 8% of Full), that illumination with the aid of airglow was sufficient to provide a useful “visible image at night” using the Day/Night Band; a streak of bright pixels was due to intense lightning activity within a line of thunderstorms just ahead of the cold front. Note: the NOAA-20 images are incorrectly labeled as Suomi NPP.

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The most common scanning strategy for GOES-R satellites since GOES-16 became operational has been “Flex” Mode, Mode 3: During each 15 minutes, 1 full disk, 3 CONUS and 30 Mesoscale scans are achieved (Link showing Mode 3 Scanning. This YouTube Video shows Mode 3 Scanning with two adjacent mesoscale sectors). (Mode 4 — continuous 5-minute full disk imagery — has been implemented as well, as noted here).

In early 2014, before launch, researchers at NOAA’s Advanced Satellite Products Branch and CIMSS in Madison, Wisconsin suggested that some of the time where the ABI wasn’t scanning (The white space in this graphic) could be used to provide larger CONUS (or PACUS) scans. This didn’t happen, in part because it changed the dimensions of an ABI sector. However, in August 2014, an email exchange with the lead ABI instrument designer from Harris Corporation led to the concept of using the extra time instead to increase the cadence of full disk imaging from every 15 minutes to every 10 minutes in the “flex” mode. (Click to see a ‘Time-time’ chart of Mode 6 for GOES-16, and for GOES-17;  You might notice that GOES-16 and GOES-17 have slightly different Mode 6 scanning strategies.  Mode-6M for GOES-17 differs because of the timings of different calibration looks meant to mitigate errors associated with the faulty Loop Heat Pipe (link 1, link 2, link 3). Changes were need to in the ground system to support this new scan mode, and those changes are now operational.

The change to 10-minute full disk imagery matches the scanning of JMA’s AHI imager (and it will match the next generation EUMETSAT imager as well). It also gives the finer time resolution in the full disk domains for monitoring convection, fires, volcanic ash plumes, turbulence, etc., in regions outside CONUS and PACUS scans. In particular, Alaska region of the National Weather Service receives full-resolution Alaska sectors created from the full-disk imagery, and those sectors will now switch from a 15-minute cadence to a 10-minute cadence.  All of Central and South America will now also have imagery every 10 minutes!

This page at the goes-r.gov website has more information on scanning strategies. You can also find more information about scanning schedules and scan sectors here.

Many Baseline Products will also adopt the 10-minute cadence.  For example, compare the GOES-16 Baseline Cloud Top Temperature imagery above, from April 2, with Mode 6 scanning and 10-minute temporal resolution at the end of the animation, with the GOES-16 Baseline Cloud Top Temperature with Mode 3 and 15-minute temporal resolution below from April 1. (An animation with Mode 6 scanning at the end showing Band 13 “Clean Window” 10.3 µm imagery is here).

Additional Full Disk animations covering a 6-hour period — 3 hours before/after the 1600 UTC Mode 6 activation time — are available from GOES-17 (Visible | Water Vapor) and GOES-16 (Visible | Water Vapor).

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The Spring Hill Fire began to burn in central New Jersey around 1745 UTC (1:45 PM EDT) on 30 March 2019. GOES-16 (GOES-East) Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images (above) showed the hot thermal signature of the fire as it burned into the subsequent nighttime hours and the following morning. Smoke from the fire drifted northeastward, reducing the surface visibility at Lakehurst Naval Air Station (KNEL), Toms River (KMJX) and Belmar (KBLM).

GOES-16 also initially viewed this area with 1-minute imagery from 1700-1859 UTC (since the Mesoscale Sector #1 normally covers New Jersey), and first displayed a fire hot spot around 1745 UTC. The animation below shows Visible imagery (0.64 µm), with Shortwave Infrared imagery in the background. One-minute data was valuable during these two hours because the rapidly moving clouds occasionally allowed brief views of the surface. It’s also easier to identify the smoke plume as a coherent structure with a 1-minute cadence (vs. the 5-minute cadence available with CONUS scans). At 1900 UTC, GOES-16 Mesoscale Sector #1 was repositioned to cover developing convection over the mid-Mississippi River Valley, so 1-minute views of New Jersey were terminated.

The GOES Fire Detection and Characterization Algorithm (the Baseline fire-detection product) is shown below. This product is not computed in Mesoscale Domains, so only CONUS imagery with a 5-minute cadence is shown. The widespread cloud cover affected the signal, but the fire was still detected. Note that the Fire Power product identified the fire pixels more frequently (consider the 1832 UTC image, for example).

The rapid growth of the fire thermal signature was apparent in a sequence of 3 daytime and 3 nighttime VIIRS Shortwave Infrared (3.74 µm) images from NOAA-20 and Suomi NPP (below). Note: some of the NOAA-20 images — 1750 UTC on 30 March, along with 0609 and 0749 UTC on 31 March — are incorrectly labeled as Suomi NPP.

Signatures of the fire were also seen in a comparison of Suomi NPP VIIRS Near-Infrared (1.61 µm and 2.24 µm), Shortwave Infrared (3.74 µm) and Day/Night Band (0.7 µm) images (below, courtesy of William Straka, CIMSS).

A little science on the night shift (thread)! We’ve gotten many questions about the smoke across central and northern NJ tonight. This smoke is originating from the Spring Hill Forest Fire in Penn State Forest in Burlington County. #njwx pic.twitter.com/OW8GmTS1Ii

— NWS Mount Holly (@NWS_MountHolly) March 31, 2019

===== 01 April Update =====

In a comparison of Terra MODIS True Color and False Color RGB images on 01 April from the MODIS Today site (above) the fire burn scar was evident in the False Color image.

The appearance of the burn scar was also seen in a before/after toggle between Terra MODIS False Color RGB images on 27 March and 01 April (below).

A closer view of the 01 April Terra MODIS False Color RGB image using RealEarth (below) showed that the northeastern edge of the burn scar was near Route 72 (which had to be closed as the fire was being contained), and may have threatened structures at Coyle Field.

===== 08 April Update =====

A 30-meter resolution Landsat-8 False Color RGB image from 08 April (above) provided a very detailed view of the Spring Hill Fire burn scar. It suggested that the fire did cross Route 72 at Coyle Field.

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