GOES-15 10.7 µm infrared channel imagery in Sitka Sector (click to enlarge)

NOAA/NESDIS placed GOES-15 in Rapid Scan Operations (RSO) mode for several hours on 7 October 2014 (link) to test RSO capabilities over different sectors of the Pacific Ocean. RSO Capabilities over the Pacific were possible in the 1990s; the testing yesterday showed they could be done again. Three sectors were scanned. The Sitka sector, above (centered near the Island of Sitka), can monitor the eastern Gulf of Alaska and western North America. The other sectors were over Hawaii (below, the Hawaii Sector) and over the western Gulf of Alaska and parts of the Bering Sea (bottom, the TPARC Sector, which sector overlaps a THORPEX experiment site).

GOES-15 10.7 µm infrared channel imagery in Hawaii Sector (click to enlarge)

GOES-15 10.7 µm infrared channel imagery in TPARC Sector (click to enlarge)

NESDIS is investigating why these RSO data did not flow into AWIPS as intended.

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Update, 15 October 2014.

A second RSO Test occurred on 15 October (Link). Data from this successful RSO test were available in AWIPS during this test. GOES-15 scanning strategies are shown here. The Hawaii sector is shown here. Data available over the Hawaii sector from 1930 to 2030 UTC on 15 October are shown below.

GOES-15 10.7 µm infrared channel imagery in Hawaii Sector (click to animate)

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MTSAT-2 0.73 µm visible channel image at 0514 UTC (click to enlarge)

The Japanese Satellite Himawari-8 was successfully launched from
southern Tanegashima Island today at 05:16 UTC. (NASA News Source). Is the plume from that launch visible in MTSAT imagery? The visible imagery with a nominal time of 0514 UTC was actually scanning Tanegashima Island at 0519 UTC, and a plume, denoted by the yellow arrow above, is visible off the southern edge of the Island. (The 0501 UTC image of the same scene, pre-launch, is here).

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Suomi NPP VIIRS Day/Night Band (0.70 µm), Infrared Imagery (11.45 µm) and Day/Night Band imagery with lightning strikes at 0842 UTC on 6 October 2014 (click to animate)

The Suomi NPP VIIRS image toggle, above, from the pre-dawn hours (3:42 am local time) on 6 October 2014 shows a 0.7 µm Day/Night Band image and an 11.45 µm Infrared image, along with observations of postive and negative lightning strikes. With ample illumination by moonlight, the “visible image at night” Day/Night Band image highlighted areas of convective overshooting tops, but also included bright horizontal stripes that are associated with intense lightning activity; after scanning a particularly bright area of lightning in Arkansas, this image also showed a darker “post-saturation recovery” stripe downscan (to the southeast), which stretched from central Arkansas into Mississippi. This vigorous convective system dropped southeastward from Oklahoma towards the Gulf of Mexico, eventually becoming a Quasi-Linear Convective System (QLCS) which produced hail and wind damage (with one fatality) across parts of northeastern Texas and far northwestern Louisiana (SPC storm reports).

GOES Sounder DPI Lifted Index (click to animate)

The southward-dropping Mesoscale Convective System followed a channel of unstable air as diagnosed by the GOES Sounder, above. Note that the Lifted Index values were smaller (less instability) along the path that the system had moved. Total Precipitable water was also enhanced in that corridor, suggesting a region where moisture return from the Gulf of Mexico was ongoing and concentrated.

GOES Infrared Imagery (10.7 µm) at 1600 UTC, and Pilot Reports of Turbulence (click to enlarge)

Mesoscale Convective Systems can exhibit signatures that suggest the presence of turbulence in the atmosphere. In the GOES-13 IR image above, parallel filaments or “transverse bands” of cirrus  (extending approximately north-south) on the poleward side of the MCS suggest the presence of turbulence, and scattered pilot reports of Moderate Turbulence confirm that. Visible MODIS Imagery, below, also shows the transverse bands, as well as the outflow boundary arcing from Houston to the northwest and north.

Terra MODIS visible imagery (0.65 µm) at 1705 UTC (click to enlarge)

An animation of hourly GOES-13 Visible imagery, below, shows the motion of the western portion of the outflow boundary as the decaying QLCS moved into the Gulf of Mexico.

GOES-13 Visible (0.65µm) imagery (click to animate)

GOES-13 6.5 µm water vapor channel imagery, below, displayed a signature of subsidence immediately upstream of the dissipating MCS, in the form of an arc of warmer/drier (yellow to orange color enhancement) brightness temperatures that extended from the Texas coast into central Arkansas. One rapidly-developing convective cell which formed along the advancing outflow boundary was responsible for severe turbulence in eastern Texas; the subtle signal of the westward-propagating outflow boundary could also be followed on the water vapor imagery.

GOES-13 6.5 µm water vapor channel images, with pilot reports of turbulence (click to play animation)

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GOES-13 Visible Imagery (0.63 µm), 1215 through 2345 UTC, 30 September 2014 (click to animate)

The visible imagery animation above shows stratocumulus over Wisconsin behind a strong early-season cold front. Careful examination of the animation will reveal the presence of at least three exhaust plumes from power plants over Wisconsin. Imagery from 1715 UTC, below, shows visible (0.63 µm) and infrared (3.9 µm and 10.7 µm) data (Click here for an image toggle without the Big Red Box). The plume is warmer in the 3.9 µm imagery, relative to its surroundings; the plume is cooler in the 10.7 µm imagery, relative to its surroundings (an enhanced version of the loop makes this even more evident). Why does the temperature difference exist?

Plumes appear darker — warmer — in the 3.9 µm imagery because of increased reflectivity in the plume: cloud droplets in the power plant plume are smaller and more reflective of 3.9 µm radiation than the cloud droplets in the surrounding stratocumulus field. The plume is cooler in the 10.7 µm imagery because the plume is higher in the atmosphere than the surrounding stratocumulus deck.

GOES-13 Visible Imagery and Infrared Imagery (0.63 µm, 3.9 µm and 10.7 µm), at 1715 30 September 2014. The Red box surrounds a Power Plant Plume (click to enlarge)

Suomi NPP overflew the area at 1836 UTC, and that imagery is shown below. The higher resolution data allows a better discrimination of the small plumes over the state. As with GOES data, the shortwave infrared (3.74 µm for VIIRS) data also shows warmer conditions over the plume compared to the surrounding stratocumulus deck.

Suomi NPP Visible Imagery and Infrared Imagery (0.63 µm, 3.74 µm and 11.35 µm), at 1836 UTC 30 September 2014. (click to enlarge)

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