Hurricane Sandy moves north of the Bahamas

October 26th, 2012
GOES-14 0.63 µm visible channel images and 10.7 µm infrared channel images (click image to play animation)

GOES-14 0.63 µm visible channel images and 10.7 µm infrared channel images (click image to play animation)

SRSO-R operations continue today with GOES-14, allowing for very high temporal resolution imaging of a sheared Hurricane Sandy as it moves away from the Bahamas. The exposed low-level circulation is apparent in the imagery, as well as strong convection north and west of the low-level center. A closer view of the exposed low-level circulation can be seen in this QuickTime movie of GOES-14 visible imagery.

A map of deep layer wind shear, below, from the CIMSS Tropical Cyclones site, shows strong shear associated with an upper level low pressure system south and west of Sandy.

Wind Shear, 1800 UTC 26 October

Wind Shear, 1800 UTC 26 October

A comparison of AWIPS images of Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel data (below) showed the exposed low-level circulation center of Sandy at 18:26 UTC (2:26 PM local time), and the deep convection to the north which exhibited cloud top IR brightness temperatures as cold as -87 C (violet color enhancement).

Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel images

Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel images

GOES-14 Super Rapid Scan Operations (SRSO) Images of Hurricane Sandy

October 25th, 2012
GOES-14 0.63 µm visible channel images (click image to play animation)

GOES-14 0.63 µm visible channel images (click image to play animation)

The GOES-14 satellite was placed into Super Rapid Scan Operations for GOES-R (SRSOR) mode to begin to provide 1-minute interal images of Hurricane Sandy on 25 October 2012. McIDAS images of GOES-14 0.63 µm visible channel data (above; click image to play animation; also available as a QuickTime movie) showed the circulation of Sandy moving northward over the islands of the Bahamas, with the development of a new convective burst in the western semicircle of the storm.

Prior to the initiation of GOES-14 SRSOR, a sequence of AWIPS images of 1-km resolution POES AVHRR 12.0 µm and Suomi NPP VIIRS 11.45 µm IR data (below) showed the circlation of Hurricane Sandy crossing the eastern portion of the island of Cuba.

POES AVHRR 12.0 µm and Suomi NPP VIIRS 11.45 µm IR images

POES AVHRR 12.0 µm and Suomi NPP VIIRS 11.45 µm IR images

A McIDAS-V image of Suomi NPP VIIRS 0.7 µm Day/Night Band data at 05:49 UTC or 1:49 AM local time (below; courtesy of William Straka, CIMSS) offered a “night-time visible” image of Sandy as its center was moving over the southern coast of Cuba.

Suomi NPP VIIRS 0.7 µm Day/Night Band image

Suomi NPP VIIRS 0.7 µm Day/Night Band image

Hurricane Sandy

October 24th, 2012
GOES-13 10.7 µm IR images (click image to play animation)

GOES-13 10.7 µm IR images (click image to play animation)

Hurricane Sandy became the tenth hurricane of the 2012 Atlantic Basin tropical cyclone season on 24 October 2012. McIDAS images of GOES-13 10.7 µm IR data (above; click image to play animation) showed the fairly rapid formation of an eye as the storm approached the eastern portion of the island of Jamaica.

A 15:21 UTC TRMM Microwave Imager (TMI) 85 GHz brightness temperature image from the CIMSS Tropical Cyclones site (below) suggested that a closed eyewall was nearly formed complete by that time.

TRMM Microwave Imagery (TMI) 85 GHz brightness temperature image

TRMM Microwave Imagery (TMI) 85 GHz brightness temperature image

A comparison of AWIPS images of 1-km resolution POES AVHRR 0.86 µm visible channel and 12.0 µm IR channel data (below) showed the eye region of Hurricane Sandy after the center of the storm was passing over Jamaica.

POES AVHRR 0.86 µm visible channel and 12.0 µm IR channel images

POES AVHRR 0.86 µm visible channel and 12.0 µm IR channel images

Glacial silt blowing off the coast of Alaska

October 21st, 2012
GOES-15 0.63 µm visible channel images (click image to play animation)

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

As high pressure associated with cold arctic air began to build over the eastern interior of Alaska and the Yukon Territory of Canada, a strong pressure gradient created intense gap winds through the channeled terrain of south-central Alaska on 21 October 2012. These winds stirred up glacial silt and then carried it down the valleys and toward the coast. GOES-15 0.63 µm visible channel images (above; click image to play animation) showed the hazy signature of a particularly large airborne plume of glacial silt as it moved offshore over the adjacent offshore waters of the Gulf of Alaska.

Suomi NPP VIIRS 0.64 µm visible channel images

Suomi NPP VIIRS 0.64 µm visible channel images

A more detailed view is provided by Suomi NPP VIIRS 0.64 µm visible channel images (above) and 1.61 µm near-IR “snow/ice channel” images (below). The largest glacial silt plume was blowing southward out of the Copper River valley (just east of Cordova, station identifier PACV) and across Prince William Sound toward Middleton Island (station identifier PAMD). Additional smaller glacial silt plumes could be seen farther east on the 20:08 UTC image, in the vicinity of Yakutat (station identifier PAYA). On the previous day (20 October), northeasterly surface winds gusted to 28 mph at Middleton Island and 20 knots at Cordova — however, the gap winds emerging from the Cooper River valley were likely much stronger.

Suomi NPP VIIRS 1.61 µm "snow/ice channel" images

Suomi NPP VIIRS 1.61 µm “snow/ice channel” images