Heightened seismic activity of the Kilauea volcano on the Big Island of Hawai’i had been ongoing since April 2018, but increased further in early May leading to a series of minor eruptions (Hawaiian Volcano Observatory | USGS) — and GOES-15 (GOES-West) Shortwave Infrared (3.9 µm) images (above) showed the nearly persistent thermal anomaly or “hot spot” (dark black to red enhancement) during the 03-05 May period. Among the numerous earthquakes, the strongest was an M6.9 which occurred at 2233 UTC on 04 May.

A nighttime image of Suomi NPP VIIRS Day/Night Band (0.7 µm) data viewed using RealEarth (below) revealed the bright glow from Kilauea, and also from the Leilani Estates subdivision where several fissure vents had opened (forcing some evacuations).

A comparison of Suomi NPP VIIRS Day/Night Band images from 03 May and 04 May (below) showed the before/after difference in the bright signal emitted by the fissure vents near Leilani Estates.

===== 06 May Update =====

Eruptions of fissure vents became more continuous in the Leilani Estates subdivision on 06 May. A comparison of GOES-15 Visible and Shortwave Infrared images (below) showed a long volcanic plume streaming southwestward, with robust thermal anomaly activity at the plume source.

An Aqua MODIS True-color Red-Green-Blue (RGB) image (below) provided a more detailed view of the volcanic plume at 0007 UTC on 07 May. Note the cluster of red thermal anomalies in the vicinity of the Leilani Estates subdivision (the source of the plume).

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Severe thunderstorms produced tornadoes, large hail and damaging winds across parts of Kansas, Nebraska and Iowa on 01 May 2018. A Mesoscale Domain Sector  provided images at 1-minute intervals — SPC storm reports are plotted on 0.64 µm “Red” Visible images (above) and 10.3 µm “Clean” Infrared Window images (below).

Many of the storms exhibited cloud-top signatures commonly associated with severe weather — for example, pronounced “enhanced-v” signatures with “cold/warm thermal couplets” were seen on Infrared imagery with the tornado-producing storms in northern Kansas and southern Nebraska (below), and both a well-defined “overshooting top” and an “above-anvil plume” were seen on Visible imagery with the Nebraska storm.

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Morning #GOESEast 1 minute mesoscale sector over #CNY showing a glimpse of the #valleyfog in the upper Susquehanna & Delaware river basins co-located with the #snow in the higher elevations of the #Catskills. Both will be gone later today. pic.twitter.com/IDuVlQANvg

— NWS Binghamton (@NWSBinghamton) May 1, 2018

As pointed out by NWS Binghamton, valley fog and higher-elevation snow cover was apparent on GOES-16 (GOES-East) Visible imagery in the Catskills of southeastern New York on the morning of 01 May 2018. A closer view comparing GOES-16 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (below) showed the dissipation of the valley fog, followed by the melting of the snow cover in higher terrain (snowfall amounts of up to 3-4 inches fell in the area on 29 April). The Snow/Ice imagery was helpful in discriminating between the brighter valley fog features and the darker snow cover.

A 250-meter resolution Terra MODIS True-color Red-Green-Blue (RGB) image acquired from the SSEC Direct Broadcast ground station (below) showed the remaining snow cover over the Catskills (near the center of the image) at 1539 UTC.

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The combination of strong winds and low relative humidity prompted the SPC to forecast elevated to critical fire weather potential across parts of the Upper Midwest on 29 April 2018. A Mesoscale Domain Sector was positioned over the region, providing data at 1-minute intervals — and “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) revealed the smoke plumes and thermal anomalies or “hot spots” (black to yellow to red pixels) associated with some of these larger fires. The most prominent fires were located in southeastern Manitoba later in the day (including the largest fire EA015, which was listed as Out of Control).

On the Visible images, also note the hazy signature of blowing dust that developed from the northern Red River Valley of North Dakota and Minnesota into southern Manitoba — with winds gusting in excess of 50 knots, the surface visibility dropped to 3 miles at Grafton ND (KGAF) and Winnipeg International Airport (located just northwest of station CXWN in southern Manitoba).

Dust storm pix taken this afternoon (Julie Helm) near Drayton ND. Wind Advisory continues thru 8pm. #ndwx #mnwx pic.twitter.com/IyksXL8dof

— NWS Grand Forks (@NWSGrandForks) April 29, 2018

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