Skies were clear over much of the southern Plains on 14 March 2018, as noted in the animation above that shows hourly GOES-16 ABI Channel 3 (0.86 µm) Imagery. Differences in absorption/reflectance between water and land yield excellent discrimination between lakes and land over Oklahoma and adjacent states.  GOES-16 ABI “Cirrus Channel” (Band 4, at 1.38 µm) shows little reflectance in the area over Oklahoma, except where cirrus clouds are present over western Oklahoma.  The rest of Oklahoma is dark because water vapor in the atmosphere is absorbing energy at 1.38 µm. An animation — also at hourly intervals — is shown below.  This uses the default enhancement in AWIPS, with reflectance values between 0 and 50 shown.

If you alter the Band 4 enhancement to change the bounds from 0-50 (the default) to 0-2 (!), as was done in the animation below showing data every 5 minutes, a gradient in reflectance becomes apparent, and surface features — specifically lakes — over central Oklahoma that are initially present slowly become obscured as the gradient moves to the east. This gradient shows differences in moisture. The atmosphere that is moving into eastern Oklahoma from central Oklahoma is slightly more moist.  (Compare the morning sounding at Amarillo, for example, with a total precipitable water of 0.38″ to the morning sounding at Little Rock, with a total precipitable Water of 0.14″)

GOES-16 data includes channel differences and level 2 products that also confirm the slow increase in moisture. The Split Window Difference field, shown below with the default enhancement (Click here to see the same animation with the Grid MidRange Enhanced enhancement), and the Total Precipitable Water, at bottom, show a slow increase in moisture. These increases were above the surface: surface dewpoints in this region (source) were not increasing greatly.

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GOES-16 Mid-level (6.9 µm) Water Vapor images (above) showed the development of a Nor’easter off the east coast of the US during the 12 March – 13 March 2018 period (surface analyses). The storm produced blizzard conditions with snowfall amounts as high as 28.3 inches and wind gusts as high as 81 mph in Massachusetts (WPC storm summary | Boston MA summary | Gray ME summary | Caribou ME summary).

GOES-16 “Clean” Infrared Window (10.3 µm) images (below) showed the cloud shied associated with the rapidly-intensifying Nor’easter on 13 March.

A closer view using 1-minute interval Mesoscale Sector “Red” Visible (0.64 µm) images on 13 March (below) included plots of hourly surface wind gusts.

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The CIMSS Natural True Color RGB, above, from 13 March 2018, shows the motion of alluvial sediment in the Gulf of Mexico in the outflow from various rivers. Muddy plumes from the Atchafalaya River in central Louisiana, the Mississippi River, and the Mobile River in Alabama are apparent. In particular, there is distinct northward motion during the 3 hours shown in this animation along the northern edge of the Mississippi River Delta.

A similar animation for 9 March 2018 is available here (courtesy Tim Schmit, NOAA and Mat Gunshor, CIMSS). Close monitoring of where the outflow from rivers is mixing with the Gulf of Mexico waters is a capability of GOES-16 Imagery when skies are clear.

Natural True Color is computed from GOES-16 Reflectance imagery using the “Blue” band (0.47 µm), the “Red” band (0.64 µm) and the “Veggie” band (0.86 µm), that latter being used to give information that in True Color Imagery from MODIS or Suomi NPP (for example) is supplied by a true “Green” band (0.55 µm).

The animation below shows True-Color imagery from MODIS for clear days between 30 January and 13 March 2018. The superior resolution of MODIS (on the Terra and Aqua spacecraft) and the presence of a 0.55 µm channel (in addition to 0.47 µm and 0.64 µm) allows for crisper imagery than from GOES-16; however, the ability to animate at small time scales over the Gulf of Mexico is a capability reserved for GOES-16 (and GOES-17, when it becomes operational). Terra and Aqua imagery are not useful if the overpass of the Polar Orbiters coincide with clouds; on days with variable cloud cover, GOES Imagery is more likely to provide useful information.

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A large Maersk container vessel caught fire in the Indian Ocean on 6 March 2018 (news report 1, news report 2), killing 4 sailors and necessitating the evacuation of the ship (the MAERSK HONAM).

Suomi NPP and NOAA-20 (which trails Suomi NPP by half an orbit) both passed over the ship fire on 6 March. As a singular light source in the middle of the Indian Ocean, the ship fire was evident in the Day Night Band imagery, as shown above, at 10.5º N and 65.8º E). The ship drifted southward in the 50 minutes between VIIRS scans from the two satellites. (Similar signatures were apparent in the 1.61 µm, 2.25 µm and 4.05 µm imagery from VIIRS on the two satellites).

One day later, on 7 March, above, Suomi NPP and then NOAA-20 (50 minutes later) again passed over the still-burning ship, then at 10.1º N and 65.6º E. A faint smoke plume is visible in the imagery from NOAA-20.

The zoomed-out image, below, might give you a better idea of how far away from the India and Africa this ship sits.

(Hat tip to William Straka, CIMSS, for the imagery and also to Steve Miller, CIRA, for alerting us to this event)

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