1-minute interval GOES-14 SRSO-R visible (0.63 µm) images (above; click image to play animation) revealed the pulsing nature of the large Cougar Creek wildfire complex burning in southern Washington (not far southwest of Yakima) on 12 August 2015. The MP4 movie file is also available as a very large (128 Mbyte) animated GIF. The second fire blow-up that began around 1700 UTC apparently produced a pyrocumulonimbus cloud, with cloud-top IR Brightness Temperature (BT) values cooling past -40º C. Large amounts of smoke were transported northward and then northeastward away from the fire source region.

During the preceding overnight hours, a comparison of  1003 UTC Suomi  NPP VIIRS shortwave Infrared (3.74 µm), Day/Night Band (0.8 µm), and Infrared (11.45 µm) images (below) showed a very large shortwave IR fire “hot spot” (yellow to red to black pixels), with the large fire glowing very brightly on the Day/Night Band image; the coldest IR BT value of the cloud streaming northward from the fire was -53º C.

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A nighttime mesoscale convective system (MCS) developed near the Arkansas/Louisiana/Mississippi border region after about 0700 UTC (2:00 AM local time) on 11 August 2015, and began to move southeastward. A comparison of 4-km resolution GOES-13 Infrared (10.7 µm) and 375-meter resolution Suomi NPP VIIRS Infrared (11.45 µm) images (above) showed the MCS around 0845 UTC, and highlighted the two advantages of polar-orbiter vs geostationary satellite imagery: (1) higher spatial resolution, for a more accurate assessment of the cloud-top IR Brightness Temperatures (the coldest GOES-13 IR BT was -73º C, while the coldest VIIRS IR BT was -83º C), and (2) minimal parallax error, for a more accurate geo-location of features such as thunderstorm overshooting tops (note how the storm appeared to be located farther to the northwest on the GOES image, centered over far southeastern Arkansas).

With the arrival of daylight the following morning, 1-minute interval GOES-14 SRSO-R visible (0.63 µm) images (below) revealed the presence of numerous short-lived overshooting tops which were penetrating the cirrus canopy of the persisting MCS. The formation of a well-defined outflow boundary was also seen, which continued to move southward during the late morning hours. The MP4 movie file is also available as a very large (73 Mbyte) animated GIF. A GOES-14 1-minute-image IR (10.7 µm) animation which shows the initial development and subsequent motion of the MCS can be seen here.

GOES-14 1-minute visible images (below) also showed the development of multi-cellular thunderstorms over parts of the Mid-Atlantic states, focused along trough axes ahead of an approaching cold frontal boundary — many of these thunderstorms produced damaging winds (SPC Storm Reports). The MP4 movie file is also available as a very large (102 Mbyte) animated GIF.

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GOES-14 is again in SRSO-R (Super Rapid Scan Operations for GOES-R) mode, affording the opportunity for 1-minute imagery over select regions of the United States. Information on the daily activity is available here; SRSO-R will continue through 21 August and serves as a reminder of the kind of routine scanning abilities that will be available when GOES-R is operational.

The images above, from the morning of 10 August, show a variety of features (thunderstorms over the Piedmont of South Carolina, North Carolina and Virginia, wave clouds over the high terrain of North Carolina, river valley fog in northern West Virginia and western Pennsylvania, fog in southern Vermont, etc.). High temporal resolution allows a better understanding of the cloud behavior.

As solar heating increased toward mid-day and the atmosphere became more unstable, clusters of convection developed over parts of the Great Lakes region as seen in the MP4 animation below. One of the thunderstorms (which developed in eastern Wisconsin ahead of an approaching cold front) produced 1.75-inch diameter hail, and a brief EF0 tornado (SPC storm reports); not far to the south, a thunderstorm wind gust of 44 mph and 1.10 inches of rainfall in 30 minutes occurred at Milwaukee International Airport (Local Storm Reports). The MP4 movie file is also available as a very large (197 Mbyte) animated GIF.

Over the Southeast US, widespread damaging wind reports resulted from strong thunderstorms forming ahead of a Mesoscale Convective Vortex that was moving southeastward across the Tennessee River Valley region (SPC Mesoscale Discussion). The GOES-14 visible images below vividly displayed the complex nature of the convection associated with this feature. The MP4 movie file is also available as a very large (87 Mbyte) animated GIF.

In the Northeast US, the GOES-14 visible images below showed convective development which was being aided by boundary layer convergence along a weak trough axis (surface analysis). 1.00-inch diameter hail was reported at Franklin in Upstate New York at 2035 UTC, and damaging winds were reported in Victor, New York at 2002 UTC and then again in Lyons, New York at 2129 UTC. The MP4 movie file is also available as a very large (59 Mbyte) animated GIF.

To access realtime GOES-14 1-minute data directly, click here or here.

One of the things SRSO-R supports is the 2015 Summer Experiment at the Aviation Weather Center. For more information on that experiment, click here.

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Hail associated with a line of rapidly developing thunderstorms near the borders of Kansas, Nebraska and Colorado heavily damaged Delta Flight 1889 bound from Boston to Salt Lake City, forcing an emergency landing in Denver (media report). An excellent blog post on the radar presentation of the system is here. What did the satellite data show? GOES Sounder Derived Product Image (DPI) values of Lifted Index (LI), above, (realtime images available here) showed instability over the High Plains of Colorado throughout the day. At 2000 UTC, for example, values greater than -8º C prevailed (subsequent cloud development prevented the retrieval of LI values using the Sounder). GOES Sounder DPI of Convective Available Potential Energy (CAPE), below, (realtime images available here) also indicated strong destabilization during the late afternoon (1600, 1800 and 2000 UTC are shown in the animation). The 08 August/00 UTC rawinsonde report from North Platte, Nebraska had LI and CAPE values of -5ºC and 1592 J/kg, respectively.

LAP (Legacy Atmospheric Profiles) from GOES-13 (from here) also showed strong instability in between extensive cloud cover: the imagery at 1600 UTC on 7 August for CAPE and LI is shown below.

Given the instability present, rapid thunderstorm development should not surprise (the region was under a Severe Thunderstorm Watch, and a Mesoscale Convective Discussion had been issued specifically mentioning the possibility of severe hail). The visible animation from GOES-13, below, from 1900 UTC on 7 August through 0145 UTC on 8 August, showed rapid convective growth, and the damaging convective cell is quite apparent growing northward over northwestern Kansas at the end of the animation.

A slower animation of GOES-13 visible images from 0045-0130 UTC is shown below.

GOES-15 also viewed the rapid development of convection. The animation from 1900 UTC on 7 August 2015 through 0145 UTC on 8 August is shown above; the animation from 0000 UTC through 0145 UTC is shown below. Convective development over northwest Kansas was racing northward.

GOES-13 Infrared (10.7 µm) brightness temperatures confirmed the quick growth of the convection. The animation below showed strong cooling starting around 0115 UTC in extreme northwest Kansas. Coldest brightness temperatures at 0100 UTC (200.2 K or -73ºC) dropped to 196.2 K (-77ºC) at 0115 UTC, then to 194.0 K (-79ºC) at 0130 UTC, 192.8 (-80.4ºC) at 0145 and 192.2 K (about -81ºC!) at 0200 UTC. The rocking animation at bottom testifies to how quickly the developing convection was able to close the gap in convection through which the aircraft was attempting to fly.

The side-by-side comparisons shown below of GOES-15 (left) and GOES-13 (right) 10.7 µm Infrared and 0.63 µm Visible images also help to demonstrate the value of more frequent images for monitoring the rapid development of such features. GOES-15 was in Rapid Scan Operations (RSO) mode, providing up to 10 images every hour (at :00, :11, :15, :22, :30, :41, :45, :52, :55, and :57), while GOES-13 was in Routine Scan mode, providing up to 4 images every hour (at :00, :15, :30. and :45). Unfortunately, there were 30-minute gaps in both GOES-15 (between 0030 and 0100 UTC) and GOES-13 (between 0015 and 0045 UTC) during the time that the new line of thunderstorms began to rapidly build northward across far northwestern Kansas, between the 2 pre-existing areas of thunderstorm activity.

In addition to the animated GIFs, MP4 versions of the Infrared and Visible images are available here and here.

The flight positions of Delta 1889 are superimposed on a composite animation of GOES-13 Infrared (10.7 µm)and Goodland, Kansas radar reflectivity, below (courtesy of Rick Kohrs, SSEC).

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