Satellite Liaison Blog

Moist upslope flow, moderate instability and 30-35 knot shear across southern Colorado led to the development of strong-severe storms during the afternoon on Monday, 26 June 2017. Given the threat for severe storms, WFO Pueblo requested (and was granted) a GOES-16 mesoscale sector (1-min imagery). The 1-min visible and IR imagery was utilized by forecasters during warning operations.

The radar operator covering the far eastern counties of southern Colorado utilized a two-panel display of 1-min VIS and IR imagery to monitor convective trends during warning operations (Figure 1). This two panel was loaded in a CAVE with his radar/warning display (All tilts dual pol radar in another CAVE). The 1-min satellite imagery  proved to be extremely valuable in identifying new updraft growth (vis signatures as well as cooling in IR) as well as early stages of updraft weakening (loss of texture in vis, warming in IR) prior to other observational datasets. Knowing where a new updraft was developing or updrafts were maintaining strength allowed the forecaster to anticipate new warning issuance or know to continue a warning on a storm. Knowing where convection was starting to decay allowed the forecaster to anticipate letting a warning go. This setup is especially valuable in enhancing situational awareness in pulse thunderstorm environments and in situations of widespread thunderstorm activity. Of course, the 1-min satellite imagery is used in conjunction with other datasets such as radar and lightning.

Figure 1: Example of warning display used by radar operator. Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/06/20170626_display.png

Below are GOES-16 Vis and IR animations of a period of severe thunderstorm issuance in Baca County, CO (Figures 2 and 3). In both the VIS and IR, one can see weakening of the updraft associated with a warning early in the loop. The warning is allowed to expire. Meanwhile, updraft growth (and development of an overshooting top and above anvil cirrus plume) is analyzed to the northwest of the old updraft, where a new warning is subsequently issued. The Pueblo, CO CWA is in the area north and west of the thick Black outline.

Figure 2: GOES-16 VIS over southeast Colorado. NWS Severe Thunderstorm Warnings overlaid. Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/06/20170627_1min_vis.gif

Figure 3: GOES-16 IR over southeast Colorado. NWS Severe Thunderstorm Warnings overlaid. Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/06/20170627_1min_vis.gif

Below is a radar animation from the event with warnings overlaid (Figure 4).

Figure 4: 26 June 2017 KPUX 0.5 degree radar reflectivity with warnings overlaid. Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/06/20170627_radar.gif

This case exemplifies how 1-min imagery from GOES-16 can aid a radar operator in warning operations. These storms were in very rural areas, but multiple 1″ hail reports were received.

– 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.”

On Tuesday, June 20, Tropical Storm Cindy became the third named tropical storm of the 2017 Atlantic Hurricane season. Cindy would threaten the TX/LA/MS Gulf coast Wednesday into Thursday, with heavy/flooding rainfall the primary threat. 1-minute satellite imagery from GOES-16 was available over the tropical system as it approached the coast. A key benefit of the high-temporal imagery for tropical monitoring has been easier identification of a center of circulation. Another key benefit is improved monitoring of convective evolution associated with the systems.

Below is a 1-min “sandwich product” animation from Cindy during the morning on Wednesday. The sandwich product is simply the 0.5 km visible imagery as an underlay, with semi-transparent 2 km IR imagery an overlay over cold (often convective) clouds. This image combination has been discussed on this blog in previous posts for use in convective situations. In this case, one can easily identify the center of circulation in the high resolution vis, while at the same time motioning cloud top temperature evolution in the IR.

Figure 1: 21 June 2017 GOES-16 VIS/IR combo over TS Cindy. Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/06/20170621_cindy4.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 Hazardous Weather Testbed 2017 GOES-R/JPSS Spring Experiment is underway in Norman, OK. The experiment will last for four total weeks (June 19, June 26, July 10, July 17) and include three National Weather Service forecasters and one broadcast meteorologist each week. Participants will have the opportunity to evaluate imagery and derived products from the GOES-16 Advanced Baseline Imager which recently became available to NWS forecasters in AWIPS. Additionally, HWT participants will be the first forecasters to evaluate the GLM lightning data in AWIPS. An updated ProbSevere Model will be demonstrated and include separate ProbWind, ProbTornado, and ProbHail probabilities. Finally, NUCAPS from JPSS will be demonstrated, including evaluation of the operational NUCAPS algorithm from Suomi-NPP, NUCAPS from MetOp A/B, and experimental NUCAPS product that is automatically modified in the low-levels.

Stay tuned to the Satellite Proving Ground blog for posts made by our participants and visiting scientists. Unfortunately, GLM data posts will not be available to the public due to the early testing stages of the data.

-Bill Line, NWS

A cluster of supercell thunderstorms developed across eastern Nebraska during the afternoon of 16 June 2017 and raced south through the state. The thunderstorms had merged into a large mature complex by early evening, and produced very strong wind gusts (many in excess of 80 mph) along its path. The system persisted after sunset, necessitating a switch from visible satellite imagery to IR. In order to ensure a smooth transition from day to night, a useful strategy is to overlay visible imagery on IR imagery. As the visible pixels fall to 0, the IR pixels will appear in their place. See below for an example from the 16 June 2017 event.

Figure 1: 16 June 2017 GOES-16 0.64 um VIS and 10.3 um IR. Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/06/20170616_vis_ir6_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.”

Conditions were favorable for very large hail, damaging winds and strong tornados during the afternoon/evening of 12 June 2017 across portions of the north-central high plains as an upper low approached the region. GOES-16 was operating in mode 3, flex mode, providing 5-min imagery over the CONUS. Additionally, mesoscale sector 2 (1-min imagery) was located over the region of particular interest where a SPC moderate risk for severe weather was highlighted.

The character of a cu field can be closely monitored in near-real time with the 0.5 km 1-min visible imagery from GOES-16. By Noon on the 12th, the development of cloud streets followed by towering cu and then orphan anvils were seen across portions of southeast Wyoming where strong heating, increasing moisture, and upslope flow were present. These early cloud features indicate that convective initiation is becoming more and more imminent.

Figure 1: 12 June 2017 GOES-16 0.5 km VIS Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/06/20170612_vis_wy_small.gif

Convection would develop quickly across southeast Wyoming shortly thereafter and begin to move east. A great way to monitor storm growth and health is to view the GOES-16 VIS and IRW in a two panel display. The VIS allows one to see important cloud details (new initiation, OTs, Enh-Vs, cirrus plumes, etc) in the highest resolution, while temperature trends (and many of those same features at lower resolution) can be monitored in the IRW. Storms that undergo more rapid cooling (in the IR) during their initial development were shown to have a higher chance of producing future severe weather. The 1-min IR imagery allows one to get a precise measurement of the cooling.

Figure 2: 12 June 2017 GOES-16 0.64 um VIS (left) and 10.3 um IR (right). Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/06/20170612_visir_wy_small2.gif

At 2100 UTC, GOES-16 was put into mode 4 (continuous full disk mode) for testing, meaning 1-min imagery would no longer be available, but 5-min imagery would continue (and be available over the full disk).

– 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.”

On 07 June 2017, GOES-East RSO was requested by WFO Pueblo given the threat for strong/severe thunderstorms, and lack of GOES-16 data until 2100 UTC due to testing. Additionally, a GOES-16 1-min mesoscale sector was moved to cover Colorado once GOES-16 testing ended. The availability of imagery was timely, as strong thunderstorms had begin to develop across southern Colorado. Of particular concern was the development of thunderstorms near and over area burn scars.

Forecasters were monitoring the 1-min visible and IR imagery as thunderstorms developed near the Junkins burn scar (southwest of Pueblo) from a late 2016 wildfire. The 1-min imagery provided the most up-to-date information on where new updrafts were developing. Updrafts could be seen redeveloping to the north of already developed thunderstorms on a track toward the burn scar prior to clear signatures on radar. A severe thunderstorm warning and flash flood warning were issued shortly thereafter as the thunderstorm strengthened and moved over the burn scar. Storms would maintain strength as they moved east over the plains, prompting several more severe thunderstorm warnings.

Figure 1: 07 June 2017 GOES-16 1-min 0.64 um visible satellite imagery. Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/06/20170607_vis_co.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.”