A comparison of Suomi NPP VIIRS true-color and false-color Red/Green/Blue (RGB) images from the SSEC RealEarth site (above) revealed the intricate structure of sea ice off the coast of Labrador, Canada on 03 May 2016. Snow cover and ice appear as shades of cyan in the false-color image (in contrast to supercooled water droplet clouds, which appear as shades of white).

A larger-scale view using GOES-13 (GOES-East) Visible (0.63 µm) images (below) showed the motion of this sea ice, which extended farther south off the coast of Newfoundland. The general southeastward ice motion was driven by the flow of the Labrador Current.

According to data from the Canadian Ice Service, the concentration of this medium to thick “first year ice” (Labrador | Labrador/Newfoundland) was as high as 9/10 to 10/10 (below). The departure of normal of portions of this ice was as high as 9/10 to 10/10 above normal.

 

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April 26 2016 was a day of well-anticipated severe weather (even a week out!) over the central and southern Plains, with a Moderate Risk of Severe Weather predicted for parts of Nebraska, Kansas, Oklahoma and Texas. The GOES-14 visible animation, above, shows the development of strong thunderstorms in north-central Oklahoma that propagated into south central Kansas, producing hail around 2000 UTC. Note the presence of an orphan anvil just downstream of the developing convection (to the south of the Green Arrow) at the beginning of the GOES-14 SRSO-R animation (that unfortunately has a 15-minute data gap starting at 1900 UTC).

How did the NOAA/CIMSS ProbSevere product perform with this severe cell? ProbSevere provides a probabilistic estimate of whether a cell will produce severe weather within the next 60 minutes. The animation below shows the quick development of the radar feature that became the hail producer. The Satellite Growth of this particular storm was not observed to be strong. Moderate satellite growth and weak glaciation was diagnosed. However, ProbSevere values became very large because of the environment in which the cell developed, because of the presence of large MRMS MESH observations, and active lightning. ProbSevere exceeded a 50% threshold at 1912 UTC, 6 minutes before the Severe Thunderstorm Warning was issued.  The Table at the bottom shows the ProbSevere components as a function of time.

According to SPC storm reports, the cell produced a brief rope tornado at 2058 UTC in far southern Kansas. This storm was blogged about at the Hazardous Weather Testbed. Click here and here for blog posts on the environmental instability.

A zoomed-in animation of the Visible Imagery shows the orphan anvil developing around 1740 UTC. (A rocking animation is here).

 

Time (UTC)	ProbSevere	MUCAPE	Env. Bulk Shear	MRMS MESH (Inches)	Satellite Growth	Satellite Glaciation	# Flashes
1854
1858	20%	4739	41.9	0.29	1.9% (Moderate)	0.02 (Weak)	0
1900	29%	4702	41.8	0.45	1.9% (Moderate)	0.02 (Weak)	0
1908	34%	4640	40.9	0.54	1.9% (Moderate)	0.02 (Weak)	5
1910	47%	4628	40.7	0.65	1.9% (Moderate)	0.02 (Weak)	13
1912	59%	4623	40.4	0.65	1.9% (Moderate)	0.02 (Weak)	24
1914	58%	4619	40.1	0.65	1.9% (Moderate)	0.02 (Weak)	24
1916	58%	4614	39.8	0.65	1.9% (Moderate)	0.02 (Weak)	24
1918	54%	4614	39.8	0.60	1.9% (Moderate)	0.02 (Weak)	24
1920	60%	4592	39.4	0.74	1.9% (Moderate)	0.02 (Weak)	20
1922	65%	4591	39.1	0.80	1.9% (Moderate)	0.02 (Weak)	20
1924	73%	4591	39.1	0.80	1.9% (Moderate)	0.02 (Weak)	25
1926	75%	4572	38.8	0.84	1.9% (Moderate)	0.02 (Weak)	26
1928	88%	4578	38.7	1.01	1.9% (Moderate)	0.02 (Weak)	31
1930	89%	4578	38.7	1.01	1.9% (Moderate)	0.02 (Weak)	36
1932	97%	4580	38.6	1.24	1.9% (Moderate)	0.02 (Weak)	49
1934	97%	4560	38.3	1.24	1.9% (Moderate)	0.02 (Weak)	58
1936	97%	4544	38.1	1.24	1.9% (Moderate)	0.02 (Weak)	58
1938	97%	4543	38.0	1.24	1.9% (Moderate)	0.02 (Weak)	58
1940	97%	4540	37.8	1.26	1.9% (Moderate)	0.02 (Weak)	58
1942	98%	4528	37.7	1.53	1.9% (Moderate)	0.02 (Weak)	56
1944	99%	4516	37.5	1.71	1.9% (Moderate)	0.02 (Weak)	56
1946	99%	4507	37.4	1.71	1.9% (Moderate)	0.02 (Weak)	56

 

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GOES-14 was in SRSO-R mode on 23 April – 24 April 2016, providing 1-minute Visible (0.63 µm) images (above; also available as a large 115 Mbyte animated GIF) which showed the development of convection over far northern Utah/Colorado, much of Wyoming, southern Montana, and far western South Dakota during the daytime hours of 23 April. Some of this convection produced moderate to heavy rainfall (and some accumulating snowfall) across Wyoming and southern Montana.

Hat tip to Jim Strain, who sent out the Tweet:

You can pick up the Storm Hill smoke column in the SD portion of Scott’s tweeted sat pix. #StormHillfire https://t.co/oSEKKhW45N

— Jim Strain (@jim_strain) April 24, 2016

Taking a closer look at the Black Hills of South Dakota with GOES-14 Visible (0.63 µm) and Shortwave Infrared (3.9 µm) images (below; also available as a large 151 Mbyte animated GIF), one can see intermittent smoke plumes from the Storm Hill Fire (located near the center of the red circle) on the Visible images during the late afternoon and early evening hours, with the continuation of a fire “hot spot” signature (dark black to yellow color enhancement) on the Shortwave Infrared images into the nighttime hours. The maximum shortwave IR brightness temperature was 324 K at 0424 UTC (10:24 pm local time); the fire hot spot became obscured by dense cloud cover after about 0600 UTC. Highways are plotted in dashed magenta lines on the images.

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The GOES-14 satellite was in SRSO-R mode on 21 April 2016, providing 1-minute Visible (0.63 um) images (above; also available as a large 253 Mbyte animated GIF) of the clouds associated with an occluded surface low (surface analyses) in the Upper Midwest. Near the end of the day, thunderstorms in Illinois produced hail of 1.00 and 1.25 inches in diameter (SPC storm reports | HWT Blog post 1 | HWT Blog post 2).

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