GOES-14 SRSO-R: central Montana wildfire

August 15th, 2015

GOES-15 (left), GOES-14 (center), and GOES-13 (right) 3.9 µm shortwave IR images [click to play MP4 animation]

GOES-15 (left), GOES-14 (center), and GOES-13 (right) 3.9 µm shortwave IR images [click to play MP4 animation]

A comparison of 4-km resolution GOES-15 (GOES-West), GOES-14, and GOES-13 (GOES-East) 3.9 µm shortwave infrared images (above; click to play MP4 animation; also available as a 9.4 Mbyte animated GIF) showed the development and evolution of the “hot spot” (dark black to yellow to red color enhancement) associated with a small wildfire that formed near the border of Fergus and Petroleum counties in central Montana during the afternoon hours on 15 August 2015. With GOES-15 Routine Scan mode “SUB-CONUS” sectors, images were available up to 6 times per hour (at :00, :11, :15, :30, :41, and :45); with GOES-13 in Rapid Scan Operations (RSO) mode, images were available up to 8 times per hour (at :00, :07, :15, :25, :30, :37, :45, and :55). The GOES-14 satellite had been placed into Super Rapid Scan Operations for GOES-R (SRSO-R) mode, providing images at 1-minute intervals to emulate what will be available with mesoscale sectors from the ABI instrument on GOES-R.

For the central Montana wildfire, the first unambiguous signature of a darker black wildfire hot spot began to appear on each satellite after about 1945 UTC, with the first color-enhanced pixels (signifying a shortwave IR brightness temperature of 331.9 K) showing up on the 2026 UTC GOES-14 image. The hottest fire pixel  on the GOES-15 images was 336.5 K at 2130 UTC, while the hottest fire pixel on GOES-13 images was 329.8 K at 2125 UTC. From 2120 to 2130 UTC, the hottest GOES-14 fire pixels were 341.2 K (the saturation temperature of the 3.9 µm detectors on that satellite).

With the finer spatial resolution of the shortwave IR detectors on the polar-orbiting MODIS (1-km) and VIIRS (375-meter) instruments, a fire hot spot was first detected on the 1857 UTC VIIRS image (below).

Terra/Aqua MODIS and Suomi NPP VIIRS 3.7 µm shortwave IR images [click to enlarge]

Terra/Aqua MODIS and Suomi NPP VIIRS 3.7 µm shortwave IR images [click to enlarge]

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.

Large Hail over the Upper Midwest

August 3rd, 2015
GOES-13 Visible (0.63µm) imagery [click to play animation]

GOES-13 Visible (0.63µm) imagery [click to play animation]

GOES-13 Sounder DPI Lifted Index, times as indicated  [click to play animation]

GOES-13 Sounder DPI Lifted Index, times as indicated [click to play animation]

Strong thunderstorms developed over the upper midwest ahead of a cold front in the afternoon of 2 August 2015. Large Hail (up to 4.25″ diameter in Ogemaw County Michigan) fell and strong winds were observed (up to 70 mph in Portage County Wisconsin) over parts of eastern Wisconsin and lower Michigan. (SPC Storm Report). The visible animation from GOES-13, top (available here as an mp4), shows the development of the storms.

The destabilization of the atmosphere was captured well with the GOES Sounder depiction of Lifted Index, shown above. Values exceeding -10º C were common in the moist air feeding into the developing thunderstorms. The GOES-R Legacy Atmospheric Profile (LAP) Algorithm for 2 August similarly shows the strong instability around Lake Michigan. Lifted Indices also exceeded -10º C.

GOES-R LAP Lifted Index, times as indicated  [click to play animation]

GOES-R LAP Lifted Index, times as indicated, times as indicated [click to play animation]

GOES-13 Sounder DPI Convective Available Potential Energy (CAPE), times as indicated  [click to play animation]

GOES-13 Sounder DPI Convective Available Potential Energy (CAPE), times as indicated [click to play animation]

The GOES-R LAP Algorithm (and the GOES-Sounder) can also compute Convective Available Potential Energy. Values for the GOES Sounder are shown above (they are routinely available here); those for the GOES-R LAP Algorithm are below. The GOES-13 Sounder showed values approaching 5000 J/kg. Values from the GOES-R LAP Algorithm show values around 3000 J/kg. Note how the spatial extent of the instability in both CAPE and LI fields matches well in the Sounder and LAP fields.

GOES-R LAP Convective Available Potential Energy (CAPE), times as indicated  [click to play animation]

GOES-R LAP Convective Available Potential Energy (CAPE), times as indicated [click to play animation]

The storms occurred on a day shortly after the Full Moon, so they were well-illuminated for the Suomi NPP Day Night Band imagery, shown below for 0751 UTC. The parallel lines of clouds over eastern Ohio and western Pennsylvania marks a wind-shift line as shown in this plot that includes surface observations. Those parallel lines of clouds were persistent, as they were present in the 0603 UTC Day Night Band imagery as well (Click here for a toggle between 0613 and 0751 UTC.)

Suomi NPP VIIRS Day Night Band Visible (0.70 µm) Imagery [click to enlarge]

Suomi NPP VIIRS Day Night Band Visible (0.70 µm) Imagery [click to enlarge]

The 11.45 µm Imagery from Suomi NPP shows evidence of overshooting tops persisting at night.

Suomi NPP VIIRS Infrared (11.45 µm) Imagery [click to enlarge]

Suomi NPP VIIRS Infrared (11.45 µm) Imagery [click to enlarge]

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]