GOES-14 SRSO-R: Thunderstorms over the ArkLaMiss and Mid-Atlantic regions

August 11th, 2015

GOES-13 Infrared (10.7 µm) and Suomi NPP VIIRS Infrared (11.45 µm) images [click to enlarge]

GOES-13 Infrared (10.7 µm) and Suomi NPP VIIRS Infrared (11.45 µm) images [click to enlarge]

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 visible (0.63 µm) images [click to play MP4 animation]

GOES-14 visible (0.63 µm) images [click to play MP4 animation]

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.

GOES-14 visible (0.63 µm) images [click to play MP4 animation]

GOES-14 visible (0.63 µm) images [click to play MP4 animation]

GOES-14 in SRSO-R Mode

August 10th, 2015

GOES-14 Visible (0.62 µm) Imagery  [click to play animation]

GOES-14 Visible (0.62 µm) Imagery [click to play animation]

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.

GOES-14 Visible (0.63 um) images [click to play animation]

GOES-14 Visible (0.63 um) images [click to play animation]

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.

GOES-14 Visible (0.63 µm) images [click to play animation]

GOES-14 Visible (0.63 µm) images [click to play animation]

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.

GOES-14 Visible (0.63 µm) images [click to play animation]

GOES-14 Visible (0.63 µm) images [click to play animation]

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.

Severe Thunderstorms over Northern Illinois

June 10th, 2015

GOES-14 Visible (0.6263 µm, top) and GOES-13 Visible (0.63 µm, bottom) imagery centered over Illinois, 10 June 2015 [Click to animate]

GOES-14 Visible (0.6263 µm, top) and GOES-13 Visible (0.63 µm, bottom) imagery centered over Illinois, 10 June 2015 [Click to animate]

GOES-14, in SRSO-R mode, captured the quick development of severe thunderstorms over northern Illinois late in the afternoon on 10 June 2015. Many of these storms produced large hail — especially in Will County and in Grundy County, where the second largest hailstone on record for the state of Illinois was measured (NWS Chicago summary). This event is also discussed on the GOES-R Hazardous Weather Testbed (HWT) Blog: before initiation, during convective initiation, lightning jumps and ProbSevere (first post, second post), and Overshooting top detection. The animation above compares GOES-14 SRSO-R imagery (top) with GOES-13 in Routine Scanning mode (until 2045 UTC) and in Rapid Scan Operations (RSO) mode after 2115 UTC on 10 June 2015 (a smaller version of this large animated gif is also available as an mp4).

The GOES-14 SRSO-R imagery depicts the convection evolving in a fluid atmosphere. Even the relatively fast GOES-13 RSO time-step cannot capture the full evolution and decay of overshooting tops.  On the 1-minute GOES-14 images, note the development of prominent cloud-top plumes which spread out southeastward away from the more robust overshooting top regions, and also cloud-top gravity waves which form along the southeastern flank of some of the larger thunderstorm anvils. Another advantage of SRSO-R compared to the routine scanning strategy using visible imagery is discussed here.

A wider-scale view of the evolution of the atmosphere on 10 June over the Upper Midwest is available here as a YouTube video, here as an mp4, and here as an animated gif image (warning: 300+ Megabyte file). A closer-scale view of the developing convection with GOES-14 visible images is available as an mp4 movie file, or on YouTube; an animation of GOES-14 10.7 µm IR images is available as an mp4 file.

POES AVHRR 12.0 µm IR channel image, with SPC storm reports of large hail and damaging winds

POES AVHRR 12.0 µm IR channel image, with SPC storm reports of large hail and damaging winds

The line of severe thunderstorms developed just ahead of a cold frontal boundary (animation) that was sagging southward and stalling across northern Illinois during the day on 10 June. About an hour before the 4.75-inch diameter hail was reported in Minooka IL (located about 12 miles southwest of Joliet, KJOT), a 1-km resolution POES AVHRR 12.0 µm IR image at 2316 UTC (above) showed that particular cluster of thunderstorms just southwest of the Chicago area around the time of initial hail report (1.25 inch diameter at 2318 UTC); less than a half hour later there was a report of 2.00 inch hail at 2345 UTC. Farther to the southwest, the larger thunderstorm complex was also producing hail and damaging winds, near and to the southwest of the region of coldest cloud-top IR brightness temperatures (-77º C) exhibited by the overshooting tops.

GOES-13 sounder Lifted Index derived product images [click to play animation]

GOES-13 sounder Lifted Index derived product images [click to play animation]

Hourly derived product images (DPI) of GOES-13 sounder Lifted Index (above) and Total Precipitable Water (below) revealed that a broad axis of instability and moisture existed across northern Illinois ahead of the approaching cold frontal boundary. Lifted Index values reached the -8º to -10º C range (red colors); Total Precipitable Water values were generally in the 40 to 50 mm or 1.6 to 2.0 inch range (red colors), with some locations as high as 53 mm or 2.1 inches (violet colors). The presence of this instability and moisture helped to create an environment favorable for the rapid growth of strong to severe convection.

GOES-13 sounder Total Precipitable Water derived product images [click to play animation]

GOES-13 sounder Total Precipitable Water derived product images [click to play animation]

Tornadic Thunderstorm over eastern Colorado

June 5th, 2015
GOES-14 Visible 0.6263 µm Visible imagery over Colorado, 2345 UTC 5 June 2015.  See text for details (Click to enlarge)

GOES-14 Visible 0.6263 µm Visible imagery over Colorado, 2345 UTC 5 June 2015. See text for details (Click to enlarge)

The Storm Prediction Center in Norman OK had the Plains of northeast Colorado and adjacent States in a Slight Risk (or higher) threat of severe weather on 4 June 2015. The visible image, above, shows a tornado-producing severe thunderstorm over Elbert County that produced a long-lived tornado, according to the SPC Storm Reports. The reported start and end points of the tornado (and observed times) are indicated as well. Elbert (farther northeast) and El Paso (farther southwest) counties are outlined.

The evolution of the tornadic cell was captured while GOES-14 was operating in SRSO-R mode. An animated gif of the evolution from 1915 UTC 4 June through 0130 UTC on 5 June is (warning: 190M animation!) here. A YouTube video of the mp4 is below. Note that the tornado formed along the obvious moisture boundary made visible by the arc of cumulus clouds south and east of the severe storm. (This post from the Hazardous Weather Testbed blog shows the moisture gradient as a gradient in CAPE) One-minute imagery allows an extraordinarily detailed look at features in the very dynamic cloud-top; overshooting tops develop and decay very quickly as the storm develops and matures. An animation of 10.7µm imagery from 2100 UTC through 0600 UTC on 5 June is available on YouTube here. Click here (180M gif) for a storm-centered animated gif of the tornadic storm (Also available as an mp4 and on YouTube).