GOES-15 10.7-micrometer image at new 'sub-CONUS' scale

A new scanning schedule that adds more sectors is being followed for GOES-15 as the satellite drifts westward towards 135 W. When GOES-15 becomes the new GOES-West, replacing GOES-11 (planned to occur on December 6th), the augmented scanning schedule will become operational, offering 1 or 2 additional scans per hour of the Continental United States (at the so-called ‘sub-conus scale’ depicted here). There images scans start at 11 and 41 minutes past each hour (except when full-disks are taken every three hours, in which case only the image at 41 minutes past the hour is produced). Visible image sizes are 2400×4800 pixels; infrared images sizes are 600×1200.

This image shows the current operational GOES-West imager scanning schedule. Here is the augmented schedule. Note the addition of small images just before the nn:15 and nn:45 images. Because GOES-15 is moving, the geographic coverage for the sub-CONUS imagery is not yet where it will be when GOES-15 is on station at 135 W Longitude.

Recall that GOES-15 has improved water vapor imagery resolution over GOES-11. (Link). In addition, the 12-micrometer channel on GOES-11 will be replaced by a 13.3 micrometer channel on GOES-15. In addition, the visible channel will subtly shift to a channel with a narrower response with a peak at 0.63 micrometers.

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GOES-13 6.5 µm water vapor channel images (click image to play animation)

A historic early season October winter storm produced snowfall amounts of 12 inches or more across 9 Northeastern US states during the 29 October – 30 October 2011 period, with a storm total snowfall as high as 32.0 inches reported at Peru, Massachusetts (HPC storm summary). McIDAS images of 4-km resolution GOES-13 6.5 µm water vapor channel data (above; click image to play animation) showed the evolution of the storm system during the period, which included rapid intensification following the approach of a jet streak and associated dry slot.

1-km resolution GOES-13 0.63 µm visible channel images (below; click image to play animation) showed a good portion of the resulting swath of snow cover on the morning of 30 October — areas of inland fog and stratus could be seen burning off across the southwestern portion of the satellite scene, and the center of the storm circulation was very evident over the adjacent offshore waters of the Atlantic Ocean.

GOES-13 0.63 µm visible channel images (click image to play animation)

An AWIPS image of 1-km resolution MODIS 0.65 µm visible channel data with overlays of ocean buoy data and ASCAT scatterometer surface winds (below) showed that buoy winds were still gusting as high as 56 knots at that time, with a number of 50-knot ASCAT winds to the west and southwest of the center of the circulation.

MODIS 0.65 µm visible channel image + buoy reports + ASCAT surface winds

A comparison of the 0.65 µm MODIS visible channel image with the corresponding false color Red/Green/Blue (RGB) image creted using the MODIS visible channel and the MODIS 2.1 µm “snow/ice” channel (below) was helpful for discriminating between liquid and supercooled water droplet cloud features (which appeared as lighter shades of white) and the swath of snow cover on the ground (or clouds composed of ice crystals, which appeared as shades of red).

MODIS 0.65 µm visible channel + MODIS false color Red/Green/Blue (RGB) image

The MIMIC Total Precipitable Water product (below; click image to play animation) indicated that the storm was able to tap into a long plume of tropical moisture (originating in the Caribbean Sea) that was feeding northeastward across the western Atlantic Ocean.

MIMIC Total Precipitable Water product (click image to play animation)

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MODIS true color and false color Red/Green/Blue (RGB) images

The first major winter storm of the season to affect the central Rocky Mountains region produced up to 19.9 inches of snowfall across parts of Colorado on 26 October 2011. On the following day, 250-meter resolution Terra MODIS true color and false color Red/Green/Blue (RGB) images from the SSEC MODIS Today site (above) showed a nice view of the resulting snow cover across northeastern Colorado (the snow cover was cyan-colored in the false color RGB image, with cloud features appearing as shades of white). The morning snow depths included 10 inches at Boulder and Greeley, with reports of 12 inches on the ground at a number of higher elevation stations.

A corresponding AWIPS image comparison of 1-km resolution MODIS 0.65 µm visible channel data and a false color RGB image created using the 2.1 µm “snow/ice channel” (below) further demonstrated the utility of using RGB imagery to discriminate between snow cover (which appeared red in this second RGB image) and cloud features (which again appeared as lighter shades of white).

MODIS visible and false color Red/Green/Blue (RGB) image

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18:13 UTC and 19:53 UTC MODIS false color RGB images

Some of the snow cover began to melt during the day across eastern Colorado, as could be seen in a comparison of the 18:13 UTC (12:13 PM local time) and 19:53 UTC (1:53 PM local time) MODIS false color RGB images (above). GOES-15 0.63 µm visible channel images at 15 minute intervals (below; click image to play animation) more clearly showed the temporal evolution of the melting snow cover.

GOES-15 0.63 µm visible channel images (click image to play animation)

CIMSS participation in GOES-R Proving Ground activities includes making a variety of MODIS images and products available for National Weather Service offices to add to their local AWIPS workstations. Currently there are 49 NWS offices receiving MODIS imagery and products from CIMSS.

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GOES-13 0.63 µm visible channel images + ASCAT scatterometer surface winds

Tropical Storm Rina rapidly intensified (CIMSS ADT plot) to hurricane intensity off the coast of Honduras on 24 October 2011 — GOES-13 0.63 µm visible channel images with an overlay of ASCAT scatterometer surface winds from the CIMSS Tropical Cyclones site (above) showed that Hurricane Rina exhibited a central dense overcast early in the day, with convective bursts near the center of the circulation.

A longer animation of GOES-15 10.7 µm IR channel images (below; click image to play animation) revealed a number of convective bursts, with large areas of the central dense overcast exhibiting cloud top IR brightness temperatures of -80ºC or colder (violet color enhancement).

GOES-15 10.7 µm IR channel images (click image to play animation)

AWIPS images of the MIMIC Total Precipitable Water (TPW) product (below; click image to play animation) suggested that Hurricane Rina may have been tapping moisture from the Eastern Pacific Ocean Intertropical Convergence Zone / Monsoon Trough.

MIMIC Total Precipitable Water product + tropical surface analysis (click image to play animation)

It is interesting to note that an increasing pressure gradient between high pressure located over the Gulf of Mexico and the deepening circulation of Hurricane Rina was beginning to enhance the intensity of dry Tehuano gap winds flowing southward into the Gulf of Tehuantepec (below).

MIMIC TPW + Tropical surface analysis + ASCAT scatterometer surface winds

===== 25 October Update =====

NOAA-16 false color Red/Green/Blue (RGB) image

On 25 October 2011, widespread high altitude cirrus “transverse banding” was seen along the western periphery of Hurricane Rina on a 1-km resolution NOAA-16 false color Red/Green/Blue (RGB) image (above), created using AVHRR visible channels 1 (0.63 µm) and 2 (0.86 µm) along with IR channel 4 (10.8 µm).

4-km resolution GOES-13 6.5 µm “water vapor channel” images (below; click image to play animation) showed that Hurricane Rina was a prolific producer of transverse banding during much of the day. The GOES-13 satellite had been placed into Rapid Scan Operations (RSO) mode, providing images as often as every 5-10 minutes.

GOES-13 6.5 µm water vapor channel images (click image to play animation)

1-km resolution GOES-13 0.63 µm visible channel RSO images (below; click image to play animation) revealed the formation of a well-defined eyewall during the afternoon hours.

GOES-13 0.63 µm visible channel images (click image to play animation)

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