Super Typhoon Nuri in the West Pacific Ocean

November 3rd, 2014
Advanced Dvorak Technique (ADT) intensity estimate for Super Typhoon Nuri

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)

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

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)

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 eye (click to enlarge)

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

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

Tropical Invest 97L in the western Atlantic Ocean

September 29th, 2014
GOES-13 0.63 µm visible channel images with METAR surface reports (click to play animation)

GOES-13 0.63 µm visible channel images with METAR surface reports (click to play animation)

Tropical Invest 97L formed near Bermuda during the pre-dawn hours on 29 September 2014. After sunrise, AWIPS II images of GOES-13 0.63 µm visible channel data (above; click image to play animation) revealed a well-defined low-level circulation spinning just to the west of Bermuda. It is interesting to note that at 12:55 UTC a waterspout was reported 4 km to the east of the Bermuda International Airport (station identifier TXKF), associated with a band of deep convection that was moving northward (below).

GOES-13 0.63 µm visible channel image with Bermuda METAR observation

GOES-13 0.63 µm visible channel image with Bermuda METAR observation

An overpass of a Metop satellite at 14:38 UTC provided a good view of the surface wind field with data from the ASCAT scatterometer instrument (below). There was one wind vector with a speed around 30 knots (green) just to the east of the center of circulation.

GOES-13 0.63 µm visible channel image with Metop ASCAT scatterometer surface winds

GOES-13 0.63 µm visible channel image with Metop ASCAT scatterometer surface winds

A comparison of Terra MODIS 0.65 µm visible channel and 11.0 µm IR channel images at 15:25 UTC (below) showed that the coldest cloud-top IR brightness temperatures of -55º C (orange color enhancement) were located to the north of the circulation center.

Terra MODIS 0.65 µm visible channel and 11.0 µm IR channel images

Terra MODIS 0.65 µm visible channel and 11.0 µm IR channel images

Hurricane Cristobal and the Saharan Air Layer

August 28th, 2014
Meteosat-10 Saharan Air Layer product (click to play animation)

Meteosat-10 Saharan Air Layer product (click to play animation)

The CIMSS Saharan Air Layer (SAL) product (above; click image to play animation) showed a large pocket of SAL (yellow to red color enhancement) drifting westward over the far western Atlantic Ocean and toward the Gulf of Mexico on 28 August 2014.

On GOES-13 0.63 µm visible channel images (below; click image to play animation), the hazy signature of the SAL dust could be seen surging westward, not far to the south of Category 1 intensity Hurricane Cristobal.

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

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

The SAL also exhibited a warm/dry signature (yellow to orange color enhancement) on the corresponding GOES-13 6.5 µm water vapor channel images (below; click image to play animation).

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

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

At 17:16 UTC, a Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image from the SSEC RealEarth web map server (below) showed that Hurricane Cristobal had developed an eye formation.

Suomi NPP VIIRS true-color image

Suomi NPP VIIRS true-color image

A comparison of AWIPS-2 images of Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel data (below) revealed that the coldest cloud-top IR brightness temperatures (-77º C, lighter gray color enhancement) were located within convection just southwest and southeast of the eye.

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

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

Air Algerie Plane Crash in Mali

July 24th, 2014
Meteosat-10 10.8 µm infrared channel images (click to enlarge)

Meteosat-10 10.8 µm infrared channel images (click to enlarge)

An Air Algerie Flight AH5017 crashed less than an hour after taking off from Ouagadougou, Burkina Faso (the southern asterisk in the animation above). Contact was lost at 0155 UTC (Press Report) and wreckage was found southeast of the Gossi, Mali (the northern asterisk in the animation above). Cloud-top IR Brightness Temperatures in the Mesoscale Convective System through which the plane flew were as cold as -78º C.

Suomi NPP was flying over Mali and Burkina Faso at 0152 UTC on 24 July and provided high-resolution infrared and Day/Night Band imagery along the flight path. The toggle below, of the VIIRS 11.45 µm infrared and 0.70 µm Day/Night Band (Imagery courtesy of William Straka, UW CIMSS) shows the convective storm. The bright lights of Ouagadougou are evident, as well as lightning streaks within the storm. (Click for zoomed-in versions of 11.45 µm and Day Night Band images)

Suomi NPP VIIRS 11.45 µm infrared and 0.7 µm Day/Night Band images (click to enlarge)

Suomi NPP VIIRS 11.45 µm infrared and 0.7 µm Day/Night Band images (click to enlarge)

============================= Added 28 July 2014 =========================

Suomi NPP VIIRS 0.7 µm Day/Night Band image (click to enlarge)

Suomi NPP VIIRS 0.7 µm Day/Night Band image (click to enlarge)

The image above includes the light flare from the actual plane crash, circled in red. Suomi NPP was passing over the crash site between 1:55:00 and 1:55:30 UTC on 24 July 2014 (Link, navigation computed from Two Line Element files). The animation below shows Day/Night Band imagery (also courtesy of William Straka, UW CIMSS) from before the crash (21 July), the time of the crash on the 24th, and after the crash (25 July).

Suomi NPP VIIRS 0.7 µm Day/Night Band imagery on three days in July (click to Animate)

Suomi NPP VIIRS 0.7 µm Day/Night Band imagery on three days in July (click to Animate)