Satellite Liaison Blog

On July 24, the National Hurricane Center requested a 1-min mesoscale sector for the early morning hours of the 25th to observe expected rapid intensification of Hurricane Hillary into a major hurricane. In past GOES-14 1-min tests, NHC found the 1-min data to be useful in center-fixing tropical storms (especially those that are disorganized) as well as in monitoring convective activity associated with the storm. This case provides an example of the 1-min data being utilized to monitor for potential rapid intensification.

Below is a 90 minute (1110 UTC – 1240 UTC) animation of GOES-16 10.3 um mesoscale imagery (Fig 1). The center of circulation is easily identified, enhanced convective activity is found in the northeast quadrant of the storm, and convection is expanding/strengthening well to the north.

Figure 1: 1110 UTC – 1240 UTC 25 July 2017 GOES-16 10.3 um IR mesoscale (1-min) imagery. Full res: https://satelliteliaisonblog.files.wordpress.com/2017/07/20170725_hillary_ir4_anno.gif

As the sun rises over Hilary and the higher resolution visible imagery is available, more detail can be seen in the cloud structure immediately surrounding the center of circulation (Fig. 2).

Figure 2: 1310 UTC – 1424 UTC 25 July 2017 GOES-16 1-min VIS. High res: https://satelliteliaisonblog.files.wordpress.com/2017/07/20170725_hillary_vis_anno.gif

– Bill Line, NWS

“The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.”

A previous blog post discussed the use of GOES-16 1-min VIS and IR imagery during warning operations. Below is an example of a vertically stacked 2-panel display of GOES-16 VIS and IR imagery (and ENI Total Lightning data, warnings) for morning severe storms in the Dakotas. The 2-panel display has proven useful for monitoring convective trends during warning operations alongside radar data, especially with 1-min data. This is especially feasible nowadays with the larger/wider AWIPS displays now in NWS offices. In the example below, persistent storm top bubbling in the VIS along with obvious OT and enhanced V/U in the IR indicate continued strong updrafts. Gravity waves atop the anvil are also noted in the VIS.

Figure 1: 19 July 2017 2-panel GOES-16 VIS/IR with ENI total lightning and NWS convective warnings overlay. Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/07/20170719_2p_8_anno.gif

The thunderstorm complex maintained its strength as it shifted to the south and east, producing damaging winds along its path.

Figure 2: GOES-16 1-min 0.64 um VIS. Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/07/20170719_ia_vis3.gif

– Bill Line, NWS

“The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.”

With a monsoon pattern well in place, an abundance of moisture was available over southern Colorado by 12 July 2017. With very weak steering flow and marginal instability present, widespread slow-moving convection was expected across the southern Colorado mountains and plains. Of most concern was the flash flood potential in the vicinity of burn scars on terrain. A slow-moving thunderstorm or train of storms over a burn scar would lead to rapid flooding in areas downhill of the scar/drainage.  Since burn scar flooding situations can arise quickly, having the most up-to-date observational data is vital to providing a timely forecast/alert. Given the threat, 1-min imagery from GOES-16 was requested by WFO-Pueblo and granted.

1-min satellite imagery from GOES-16 enhances forecaster situational awareness to areas of new convective development (or movement of storms) over burn scars. Forecasters can diagnose, with more lead-time than ever and in essentially real-time, the development of convection posing a threat to a burn scar. This, in turn, will alert the forecaster to monitor radar closely over that area and notify points of contact of the impending threat.

Similarly, early signs of storm weakening could be identified in the 1-min data, signifying to a forecaster the area would be safe for the time being. This was mostly the case on the 12th. Though widespread convection with heavy rainfall occurred, they mostly avoided the burn scars. The example below shows convection developing quickly southwest of the Junkins burn scar a couple of times, but weakening as they approached the scar (Figure 1).

Figure 1: GOES-16 1-min visible/IR image combination. Black contours represent burn scar outlines. Junkins burn scar is in center of image. Note convective bursts southwest of the burn scar weakening prior to reaching the burn scar. Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/07/20170712_1min_sw_junkins.gif

The heaviest rainfall ended up falling in far eastern Colorado in Kiowa county. Reports of over 2″ of rain were received, and radar estimated over 5″ in one area. The heaviest rainfall occurred where GOES-16 indicated the presence of highest Precipitable Water amounts (over 1.2″), shown in Figure 2.

Figure 2: GOES-16 Precipitable Water.

– Bill Line, NWS

“The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.”

GOES-16 1-min visible imagery provides a great view of the tornado storm along the North Dakota/Minnesota border on 11 July 2017. Overlaying 1-min NLDN lightning data provides the forecaster with a great display of trends in storm updrafts. Main updraft as seen in satellite imagery is shifted to the north and west of lightning core due to parallax effect. Also overlaid in the animation are NWS tornado (white) and severe thunderstorm (grey) warnings, as well as local storm reports (black).

Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/07/20170711_1min_ndvis4_2.gif

– Bill Line, NWS

“The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.”

Rocking animations of satellite imagery provides an alternative perspective on trends for important atmospheric phenomena such as convective initiation. Here we are rocking one hour of GOES-16 VIS for initiation in the Oklahoma Panhandle on 03 July 2017. Just to the east, SPC highlighted an Enhanced Risk for severe weather, particularly wind.

Figure 1: 03 July 2017 GOES-16 0.64 um VIS. Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/07/20170703_ok_vis_rock4.gif

– Bill Line, NWS

“The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.”

With upslope flow, moderate instability and strong flow aloft, supercell thunderstorms developed off the Palmer Divide and quickly moved east during the late afternoon/early evening of 29 June 2017. These storms produced numerous hail reports. Below is 5-min, 0.5 km visible imagery from GOES-16. Of note is the storm-split observed with the first area of convection, the southern storm making a sharp right turn. Considerable rotation was noted with this storm, though cloud bases were quite high. Convection to the west continued to initiate off of the higher terrain of the Palmer Divide thereafter.

Figure 1: 29 June 2017 GOES-16 0.64 um VIS in east-central Colorado. Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/06/20170629_co_vis4.gif

– Bill Line, NWS

“The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.”

The large wildfires out west provide an opportunity to experiment with RGB’s. RGB imagery provides a great opportunity to combine multiple channels or channel differences into one image. Three features unique to wildfires detectable by GOES-16 include the hotspot (3.9 um), smoke (0.47 or 0.64 um), and burn scar (0.86 um). The RGB recipe included in this post is: Red – 3.9 um, Green – 0.86 um, Blue – 0.47 um. In this RGB, hotspots appear red, smoke plumes appear blue/cyan, and burn scars appear dark/brown. Vegetated surfaces appear green and water appears dark. See RGB below along with the 3 individual contributing bands with their color table set to the range included in the RGB. Instead of looking at three different channels to view these three features associated with wildfires, this RGB allows a forecaster to simply view one image.

RGB

Red: 3.9 um

Green: 0.86 um

Blue: 0.47 um

– Bill Line, NWS

“The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.”