On November 30 at 1430 UTC, GOES-16 began it’s drift from the checkout position at 89.3W to the GOES-East position at 75.2W. Starting around 1330 UTC, the ABI, EXIS, GLM, SUVI, SEISS instruments have been placed in safe or diagnostic modes with no data capture or distribution. The satellite will drift east at 1.41°/day until it arrives at it’s new position on December 11. Data collection and distribution will resume sometime between December 14-20. At that time, GOES-16 will officially become GOES-East. GOES-16 ABI imagery will no longer require the “preliminary, non-operational data” tag! GOES-13 (current GOES-East) will drift to 60W during the period of January 2-22. The final GOES-16 full disk images from the checkout position are below (Fig 1). For more detailed information on the drift plan, visit: http://www.goes-r.gov/users/transitiontToOperations.html.

Figure 1: 30 November 2017 GOES-16 6.2 um Water Vapor Imagery, 15-min full disk. Full res

After GOES-16 comes back online, the data will then be available in the “East Full Disk/CONUS/Mesoscale” AWIPS menus (instead of “Center” menus). Additionally, the GOES-East portion of the blended GOES East/West imagery products (located at the top of the “Satellite” menu in AWIPS) will be missing once GOES-13 moves in January. Procedures will need to be updated to account for these changes.

-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.”

An impressive upper-level trough brought significant snowfall to the Rocky Mountains on 17 November 2017. The storm system accelerated east through the evening and deepened a surface low and associated cold front. Convection developed along this front already during the morning of the 18th, including a few early day severe storms. Storms were developing within an SPC slight risk and severe thunderstorm watch, the main threat being damaging wind gusts.

The progression of the upper level trough is diagnosed in GOES-16 water vapor imagery. Entering northwest Colorado at the start of the loop, the shortwave accelerates southeast through the state into the Texas Panhandle and then east into Oklahoma by the end of the loop. Convection initiates at the end of the loop along a cold front ahead of the main shortwave energy.

Figure 1: 18 November 2017 GOES-16 15-min 6.2 um Water Vapor Imagery. Full res

Convection developed within the bounds of the default mesoscale sector 2, so no request was made. It is recommended that offices still make a mesoscale sector request even if the phenomenon is in a default sector, as other requests could move the sector. 1-min visible imagery from early in the day shows the development of strong-to-severe storms along the cold front heading towards Indianapolis.

Figure 2: 18 November 2017 GOES-16 1-min VIS. Full res

-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 GOES-16 Day Cloud Phase Distinction RGB can be used during the day to differentiate various cloud types/layers, including over snow cover, a task which is often difficult with visible imagery alone given similarly moderate-high reflectance values. Further, clouds that are most likely producing snowfall can be differentiated from those that are not. The Day Cloud Phase Distinction RGB is a “simple” RGB available in AWIPS that combines the VIS with IR window and snow/ice bands to differentiate these cloud types and snow. A few scenes from 10 November 2017 will be analyzed.

First we discuss the components of the Day Cloud Phase Distinction RGB. The red component to the RGB is the 10.35 um IR window channel. Warmer surfaces (land surface, snow, low clouds) will have little to no red, while progressively colder surfaces (high clouds) will have more red. The green component is the 0.64 um visible channel. Less reflective surfaces (bare ground) will have less green, while highly reflective surfaces (clouds, snow) will have more green. Finally, the blue component is the 1.61 um snow/ice band. Low reflectance surfaces (ice clouds, snow) will have very little blue, while more highly reflective surfaces (water clouds) will have more blue. Bare ground tends to be somewhere in-between.

The Day Cloud Phase Distinction RGB is analyzed for a scene centered over Colorado (Fig 1). The bare ground appears a dark blue given a lack of red (warm in IR), lack of green (not very reflective in VIS), and moderate amount of blue (land surface=moderately reflective in snow/ice band). Bodies of water will appear closer to black given very low reflectance in the VIS and NIR channels. Looking over southern Colorado, the bright red color indicates high cirrus clouds: there is a lot of red (cold in IR), moderate green (moderately reflective in VIS) and low amount of blue (ice particles=not reflective in snow/ice band). The shades of light blue to aqua colors represent low water clouds: there is very little red (warm in IR), moderate green (moderately reflective in VIS), and higher values of blue (water droplets=highly reflective in snow/ice band). Snow cover appears green: there is very little red (warm in IR), moderate green (reflective in VIS), and low amount of blue (ice particles=not reflective in snow/ice band). Looking at this scene using this RGB, one can easily see that there are high, thick ice clouds over much of southeast Colorado, low water clouds in the Arkansas River Valley from the edge of the thick cirrus to Canon City and in the Colorado Springs area, and under the thinner cirrus in far eastern Colorado and western Kansas. The snow on the mountains is also easy to distinguish.

Figure 1: 10 November 2017 GOES-16 Day Cloud Phase Distinction RGB over Colorado. Full res

The various features stand out much better in the RGB when compared to the VIS (Fig. 2).

Figure 2: 10 November 2017 GOES-16 Day Cloud Phase Distinction RGB and VIS over southeast Colorado. Full res

Looking at the scene over Montana, there is widespread snow cover (green), high clouds over the Canadian border (red), and low clouds over the snow  (gray). The low clouds appear grayer up north because these low water clouds are in a much colder airmass (more red) compared to south in Colorado, and therefore contain nearly equal amounts of red, green, and blue (Fig. 3).

Figure 3: 10 November 2017 GOES-16 Day Cloud Phase Distinction RGB and VIS over Montana. Full res

Looking east over Lake Michigan, lake effect snow bands stand out as bright green/yellow (low clouds are relatively warm so moderate-low red, contains ice so low blue, cloud so at least moderate green) versus the surrounding pure water clouds that are gray/aqua. Including radar imagery, you can see that the highest reflectivity lies under the bright green/yellow regions where we know ice processes are occurring (Fig. 4).

Figure 4: 10 November 2017 GOES-16 Day Cloud Phase Distinction RGB and VIS and radar reflectivity mosaic over Lake Michigan Full res

Deep convection (thick clouds with ice) will appear yellow or very bright red or green due to the very high levels of red (very cold) and green (very bright) but low amounts of blue (ice not reflective at 1.6 um).

Shallow fog  was present in the river valleys along the Canadian/US border in northeast Montana and northwest North Dakota on 13 November. The river valley fog resided on the edge of snow  and bare land, making it difficult to track the evolution in any single band. The RGB allowed for easy detection and tracking of this fog during the day (Fig. 5).

Figure 5: 13 November 2017 GOES-16 imagery over Montana/North Dakota/Canada boundaries. Full res

-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.”

An early season winter storm brought accumulating snowfall to southern Colorado on 7 November 2017. While the mountains experienced the greatest snow accumulations, parts of the plains near and west of I-25 measured over an inch, with mainly less than an inch falling east of the I-25 corridor. GOES-16 data provided some helpful insights into this system.

Water vapor imagery captured the impressive shortwave trough as it approached and moved over southern Colorado. The shortwave can easily be identified as the dry/warm slot in the flow (with clouds developing to its northeast). Additionally, the core of the upper-level jet is identified in water vapor imagery as a sharp south-north transition to warmer temperatures (dryer atmosphere) over the southern part of the state.

Figure 1: 7 November 2017 GOES-16 6.19 um water vapor imagery. Full res

GOES-16 Derived Motion Winds also highlighted the exceptionally strong jet over the region, with some winds measuring to 150 knots around 300 mb. Aircrafts reported moderate turbulence in the area at that level.

Figure 2: 7 November 2017 GOES-16 6.19 um water vapor imagery, derived motion winds. Full res

Finally, the GOES-16 nighttime microphysics RGB highlighted the bands of snow versus liquid clouds. Since the snow bands have ice, the green component (fog difference) will be less. Additionally, these clouds are slightly colder, leading to less of a blue component. Therefore, the clouds containing snow will have more of a red/orange tint compared to the liquid low clouds which appear ~light green. The upper-level cirrus clouds speeding by in the southern part of the scene appear deeper red to black.

Figure 3: 7 November 2017 GOES-16 Nighttime Microphysics RGB. Full res

-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.”