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

Super Typhoon Francisco became the third Category 5 tropical cyclone of 2013 on 19 October 2013, as it intesified over the West Pacific Ocean northwest of Guam. 4-km resolution MTSAT-2 10.8 µm IR channel images (above; click image to play animation) showed the evolution and track of the eye of Francisco during the 17-19 October period (the island of Guam is in the lower right corner of the images). Note the trochoidal motion or “wobble” that is exhibited by the eye of the tropical cyclone as it tracked northwestward – this is caused by changes within the inner core structure of the storm, such as convective asymmetries.

1-km resolution MTSAT-2 0.73 µm visible channel images (below; click image to play animation) revealed better details of the eye and eyewall structure during the daylight portion of 18-19 October. The lowering October sun angle tended to more brightly illumimate the sloped surface of the northern quadrant of the eye.

MTSAT-2 0.73 µm visible channel images (click to play animation)

A McIDAS-V comparison of 375-meter resolution Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm thermal IR channel images at 15:48 UTC on 18 October (below; images courtesy of William Straka, CIMSS) showed a good example of the so-called “stadium effect”: the eye diameter appeared larger on the VIIRS IR image than on the corresponding “visible image at night” from the VIIRS Day/Night Band, because the clouds along the edges of the eye were steeply sloping outward with height.

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

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Suomi NPP VIIRS 0.7 µm Day/Night Band, IR BTD “Fog/Stratus Product”, and 11.45 µm IR images

Parts of Kansas received up to 5-6 inches of snowfall on 18 October 2013 (NWS Local Storm Reports). The following night, after the clouds associated with the storm system had moved eastward, the southwest-to-northeast oriented bands of snow cover could be clearly seen on an AWIPS image of Suomi NPP VIIRS 0.7 µm Day/Night Band data at 08:33 UTC or 3:33 AM local time (above). Due to ample illumination from a Full Moon, the bands of fresh snow appeared quite bright, as did the back edge of the stratus cloud deck that covered far eastern Kansas and western Missouri (which showed up well on the IR brightness temperature difference “fog/stratus product” image). A thin patch of mid-level clouds was also moving over north-central Kansas — the 11.45 µm IR brightness temperatures of that cloud feature were generally warmer than -20º C (cyan color enhancement).

After sunrise on the next day (19 October), GOES-13 0.63 µm visible channel images (below; click image to play animation) showed that the bands of snow cover melted rather quickly, due to the relatively high October sun angle.

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

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MTSAT-2 visible channel (left) and shortwave IR channel (right) images (click to play animation)

Numerous bush fires began to burn in state of New South Wales near Sydney, Australia on 16-17 October 2013. On a comparison of MTSAT-2 visible channel and shortwave IR channel images (above; click image to play animation) some of the southeastward-drifting smoke plumes were evident on the visible images, while numerous fire “hot spots” (dark black pixels) could be seen on the shortwave IR images. Toward the end of the animation (06:32 UTC on 17 October), the hot fire pixels grew in areal coverage as winds increased in association with a cold frontal passage.

A 48-hour plot of surface data for Sydney Airport (below) showed that smoke reduced the surface visibility to 4-5 miles for several hours on 17 October. Prior to the passage of the cold front, surface air temperatures were unseasonably hot (in the middle 90s F), with wind gusts as high as 38 knots. In addition, note the sharp drop in dew point temperature to -2º F at 04 UTC on 17 October.

Plot of Sydney Airport surface meteorolofical data

A 250-meter resolution Aqua MODIS true color image from the NASA EOSDIS Worldview site (below) offers a closer view of the smoke plumes in the Sydney area.

Aqua MODIS true color image

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

McIDAS images of MTSAT-2 10.8 µm IR channel data (above; click image to play animation) showed the center of Typhoon Wipha moving just southeast of Japan on 15 October 2013. The asterisk at the center of the images denotes the location of Tokyo Narita International Airport — many areas in the Tokyo region received very heavy rainfall which caused flooding and mudslides. At Izu Oshima island just south of Tokyo, rainfall rates were as high as 11.8 mm (4.7 inches) per hour, with a 24-hour rainfall total of 824.9 mm (32.5 inches).

AWIPS images of the MIMIC Total Precipitable Water (TPW) product (below; click image to play animation) revealed the large amount of tropical moisture that was transported northward toward Japan as Wipha began its poleward recurvature. At the end of the animation Wipha began its extratropical transition as it merged with a cold front that was exiting Asia and beginning to move southeastward across the North Pacific Ocean.

MIMIC Total Precipitable Water product, with surface analyses (click to play animation)

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