GOES-15 6.5 µm water vapor images and atmospheric motion vector (AMV) winds

As seen on a sequence of 3-hourly GOES-15 (GOES-West) 6.5 µm water vapor images with satellite-derived atmospheric motion vector (AMV) winds from the CIMSS Tropical Cyclones site (above), a weak but persistent trough aloft over the Hawai’i region was acting to destabilize the atmosphere and create an environment conducive to the development of widespread showers and thunderstorms — some of which were producing heavy downpours over parts of the island chain — during the 04-05 November 2014 period.

Due to radar outages, the NWS forecast office in Honolulu HI requested that the GOES-15 satellite be placed into Rapid Scan Operations (RSO) mode (NOAA/NESDIS bulletin), providing 10 images per hour (compared to only 4 per hour during routine operations). An animation of GOES-15 0.63 µm visible channel images (below; click image to play animation) begins at 17:30 UTC with routine 15-minute interval images, and then after 21:30 UTC transitions into the RSO images to demonstrate how the development and motion of features can be more carefully monitored with improved temporal resolution.

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

Additional details on GOES-15 RSO sectors which were implemented during October 2014 can be found here.

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Advanced Dvorak Technique (ADT) intensity estimate for Super Typhoon Nuri

A plot of the Advanced Dvorak Technique (ADT) intensity estimation for Super Typhoon Nuri (above) shows that the tropical cyclone went through a period of rapid intensification early in the day on 02 November 2014, reaching Super Typhoon strength with sustained winds of 155 knots later in the day.

During this period of rapid intensification, MTSAT-2 10.8 µm IR channel images (below; click image to play animation; also available as an MP4 movie file) showed the development of a small “pinhole” eye (with a diameter of about 15 km); as the storm began to recurve to the north and northeast, a bit of trochoidal motion or “wobble” of the eye was also evident. The coldest cloud-top IR brightness temperatures were -88º C (darker violet color enhancement).

MTSAT-2 10.8 µm IR channel images (click to play animation)

A 375-meter resolution Suomi NPP VIIRS 11.45 µm IR channel image (below; courtesy of William Straka, SSEC) showed great detail in the storm top temperature structure within the eyewall region of Nuri at 17:12 UTC or 2:12 am local time.

Suomi NPP VIIRS 11.45 µm IR channel image

During the daylight hours,  the COMS-1 satellite provided 15-minute interval 0.675 µm visible channel images (below; click image to play animation; also available as an MP4 movie file) which revealed the presence of mesovortices within the eye of Super Typhoon Nuri.

COMS-1 0.675 µm visible channel images (click to play animation)

============================= Added 11/04/2014 =====================

Suomi NPP VIIRS 0.7 µm Day Night Band and 11.45 µm Infrared imagery during the overnight hours (16:49 UTC or 1:49 am local time) on 03 November showed a strong, well-organized system. Ample illumination from the Moon in a Waxing Gibbous phase (94% of full) helped to highlight the “visible image at night” capability of the Day/Night Band.

Suomi NPP VIIRS Day Night Band and 11.45 µm Infrared images of the typhoon eye (click to enlarge)

Suomi NPP VIIRS Day Night Band and 11.45 µm Infrared images of the typhoon (click to enlarge)

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GOES-13 3.9 µm shortwave infrared channel images (click to enlarge)

The launch of an Antares rocket from Wallops Island, Virginia, failed on October 28th (NASA Statement on the failure). The thermal signature from the explosion and fire is evident in the animation of GOES-13 3.9 µm imagery above, within the red circle: the IR brightness temperature was 292.2K on the 22:30 UTC image (darker black pixel), compared to 286.9 and 286.7 K on the 22:15 UTC and 22:45 UTC images, respectively. The nominal time of the satellite image with the warm pixel is 22:30; however, the actual satellite scan time at Wallops Island’s latitude is 22:33 UTC. The launch was at 22:22 UTC.

On a side note, another feature that stands out in the GOES-13 3.9 µm images is the warm signature (darker black enhancement) of the waters of the Gulf Stream. A comparison of the Suomi NPP VIIRS Sea Surface Temperature product at 06:47 UTC (2:47 am local time) and 18:11 UTC (2:11 pm local time), below, showed a number of eddy features along the edges of the warm (darker red) Gulf Stream.  Strong winds associated with a Nor’easter storm several days earlier helped to create these eddies.

Suomi NPP VIIRS Sea Surface Temperature product (click to enlarge)

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

McIDAS images of GOES-15 0.63 µm visible channel data (above; click image to play animation) showed the hazy signature of airborne glacial silt drifting southward out of the Copper River valley and over the adjacent waters of the Gulf of Alaska on 28 October 2014. The strong winds lofting the silt were very localized to the Copper River valley itself, with cold dense arctic air from further inland (air temperatures were 8 to 10º F at Gulkana, PAGV) accelerating through narrow mountain passes — note how winds at nearby Cordova (PACV) were generally calm during much of the period. As the western edge of the airborne silt reached Middleton Island (PAMD), the surface visibility dropped as low as 5 miles.

AWIPS II images of Suomi NPP VIIRS data provided a better view of the aerial coverage of the glacial silt: a comparison of VIIRS 0.64 µm visible channel and 1.61 µm near-IR “snow/ice channel” images (below) showed that the 1.61 µm image offered better contrast to help locate the edges of the feature. This 1.61 µm channel imagery will be available from the Advanced Baseline Imager (ABI) on GOES-R.

Suomi NPP VIIRS 0.64 µm visible channel and 1.61 µm near-IR “snow/ice channel” images

Two consecutive VIIRS 1.61 µm images (below) revealed the changes in aerosol coverage between 21:43 UTC and 23:22 UTC.

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

The more dense portion of the airborne glacial silt particle feature exhibited a slightly warmer (darker gray) appearance on VIIRS 3.74 µm shortwave IR images, due to efficient reflection of incoming solar radiation.

Suomi NPP VIIRS 3.74 µm shortwave IR images

A VIIRS true-color Red/Green/Blue (RGB) image from the SSEC RealEarth site (below) offered a good view of the coverage of the glacial silt at 21:45 UTC.

Suomi NPP VIIRS true-color image

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