Bush fires in eastern Australia

November 8th, 2019 |

JMA Himawari-8 “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and Longwave Infrared Window (10.4 µm) imagery (below) showed the evolution of smoke plumes, hot 3.9 µm fire thermal anomalies (red pixels) and cloud-top infrared brightness temperatures of isolated pyrocumulus associated with bush fires that were burning in far eastern parts of New South Wales and Queensland, Australia from 1900 UTC on 07 November to 0800 UTC on 08 November 2019. With strong northwesterly surface winds, many of the fire thermal anomalies exhibited rapid southeastward runs toward the coast. That region of Australia had just experienced severe to record 3-month rainfall deficiencies — which included the driest October on record for the southern third of the country.

Himawari-8

Himawari-8 “Red” Visible (0.64 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Himawari-8 Shortwave Infrared (3.9 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Himawari-8 Shortwave Infrared (3.9 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Himawari-8 Longwave Infrared Window (10.4 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Himawari-8 Longwave Infrared Window (10.4 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Himawari-8 True Color Red-Green-Blue (RGB) images created using McIDAS-V (below) provided another view of the dense smoke plumes from 0000-0610 UTC. Toward the end of the animation — in the upper left portion of the satellite scene — plumes of blowing dust could be seen moving eastward from farther inland.

Himawari-8 True Color RGB images (credit: Bob Carp, SSEC) [click to play animation | MP4]

Himawari-8 True Color RGB images (credit: Bob Carp, SSEC) [click to play animation | MP4]

A combination of Suomi NPP VIIRS True Color RGB and Shortwave Infrared (4.1 µm) imagery at 0328 UTC (below) revealed hot thermal signatures of the fires (yellow to red enhancement) at the source of the smoke plumes.

Suomi NPP VIIRS True Color RGB + Shortwave Infrared (4.1 µm) imagery at 0328 UTC [click to enlarge]

Suomi NPP VIIRS True Color RGB + Shortwave Infrared (4.1 µm) imagery at 0328 UTC (credit: Bob Carp, SSEC) [click to enlarge]

A toggle between a Suomi NPP VIIRS True Color RGB image and a display of Sentinel-5 TROPOMI Tropospheric Vertical Column NO2 (below) indicated high NO2 concentrations immediately downwind of these fires.

Suomi NPP VIIRS True Color RGB image + TROPOMI Tropospheric Vertical Column NO2 [click to enlarge]

Suomi NPP VIIRS True Color RGB image + Sentinel-5 TROPOMI Tropospheric Vertical Column NO2 (credit: Bob Carp, SSEC) [click to enlarge]

The dense smoke plumes were also evident in a sequence of 3 VIIRS True Color RGB images from NOAA-20 and Suomi NPP, as visualized using RealEarth (below).

NOAA-20 and Suomi NPP VIIRS True Color RGB images [click to enlarge]

VIIRS True Color RGB images from NOAA-20 and Suomi NPP [click to enlarge]

Smoke reduced the surface visibility to 3 miles or less at Grafton (YGFN) from 03-05 UTC (below).

Time series of surface report data from Grafton, New South Wales [click to enlarge]

Time series of surface report data from Grafton, New South Wales [click to enlarge]


Rope cloud in the East Pacific Ocean

January 16th, 2019 |
GOES-17

GOES-17 “Red” Visible (0.64 µm) image, with an overlay of the 12 UTC surface analysis [click to enlarge]

* GOES-17 images shown here are preliminary and non-operational *

An 1802 UTC GOES-17 “Red” Visible (0.64 µm) image with an overlay of the 12 UTC surface analysis (above) revealed a well-defined rope cloud which stretched for nearly 1000 miles, marking the cold front position at the time of the image. Rope clouds can therefore be used to diagnose the exact location of the leading edge of a cold frontal boundary between times when surface analyses are available. In this case, the cold front was associated with a Hurricane Force low over the East Pacific Ocean on 16 January 2019 (surface analyses).

GOES-17 "Red" Visible (0.64 µm) images [click to play animation]

GOES-17 “Red” Visible (0.64 µm) images [click to play animation]

An animation of GOES-17 Visible images is shown above, with a zoomed-in version closer to the rope cloud displayed below.

GOES-17 "Red" Visible (0.64 µm) images [click to play animation]

GOES-17 “Red” Visible (0.64 µm) images [click to play animation]

An even closer look (below) showed that the rope cloud was only about 2-3 miles wide.

GOES-17 "Red" Visible (0.64 µm) images [click to enlarge]

GOES-17 “Red” Visible (0.64 µm) images [click to enlarge]

When the 18 UTC surface analysis later became available, a close-up comparison with the 1802 UTC GOES-17 Visible image (below) indicated that the northern portion of the cold front (as indicated by the rope cloud) was slightly ahead of — and the southern portion slightly behind — the smoothed cold frontal position of the surface analysis product.

1802 UTC GOES-17 "Red" Visible (0.64 µm) image, with an overlay of the 18 UTC surface analysis [click to enlarge]

1802 UTC GOES-17 “Red” Visible (0.64 µm) image, with an overlay of the 18 UTC surface analysis [click to enlarge]

NOAA-15 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images at 1617 UTC [click to enlarge]

NOAA-15 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images at 1617 UTC [click to enlarge]

1-km resolution AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images of the rope cloud were captured by NOAA-15 at 1617 UTC (above) and by NOAA-18 at 1710 UTC (below). Along the northeastern portion of the rope cloud, there were a few convective clouds which exhibited cloud-top infrared brightness temperatures as cold as -55 to -60ºC (darker shades of red) and were tall enough to be casting shadows due to the low morning sun angle.

NOAA-18 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images [click to enlarge]

NOAA-18 AVHRR Visible (0.63 µm) and Infrared Window (10.8 µm) images at 1710 UTC [click to enlarge]


===== 17 January Update =====

GOES-17 True Color RGB images [click to play animation | MP4]

GOES-17 True Color RGB images [click to play animation | MP4]

On the following day, another rope cloud (one that was more fractured) was seen moving across Hawai’i as a cold front passed the island of Kaua’i — the southeastward progression of the rope cloud was evident on GOES-17 True Color Red-Green-Blue (RGB) images (above)  from the UW AOS site.

Surface observations plotted on GOES-17 Visible images (below) showed the wind shift from southwest to north as the cold front moved through Lihue on Kauwa’i around 00 UTC.

GOES-17

GOES-17 “Red” Visible (0.64 µm) images, with plots of surface reports [click to play animation | MP4]

===== 18 January Update =====

Suomi NPP VIIRS Day/Night Band (0.7 µm) image, with and without buoy observations [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) image, with and without buoy observations [click to enlarge]

Not all rope clouds are associated with cold fronts; with ample illumination from the Moon — in the Waxing Gibbous phase, at 90% of Full — a Suomi NPP VIIRS Day/Night Band (0.7 µm) image (above) provided a “visible image at night” of a rope cloud in the northern Gulf of Mexico which highlighted a surface wind shift axis.

A sequence of VIIRS Day/Night Band images from NOAA-20 and Suomi NPP (below) showed the movement of the rope cloud during a time span of about 1.5 hours.

NOAA-20 and Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]

NOAA-20 and Suomi NPP VIIRS Day/Night Band (0.7 µm) images [click to enlarge]

Super Typhoon Yutu makes landfall on Tinian and Saipan

October 24th, 2018 |

Himawari-8 “Clean Window” Infrared (10.41 µm) Imagery, 0900-1540 UTC on 24 October 2018 (Click to animate)

Himawari-8 Clean Window Infrared (10.41 µm) imagery shows Super Typhoon Yutu poised to hit Tinian and Saipan in the Marianas Islands, to the northeast of Guam. The 0900 UTC Advisory from the Joint Typhoon Warning Center shows a storm with sustained winds of 145 knots, with strengthening forecast. JMA estimates a surface pressure of 905 hPa! (Link)

(Himawari data courtesy JMA and the NWS Pacific Region)

Update: Landfall on Tinian and Saipan occurred just before 1500 UTC; a closer view using 2.5 minute rapid scan Himawari-8 imagery can be seen here (station plot PGSN is Saipan, where reliable observations ceased after 1452 UTC).

Added: From William Straka, CIMSS. NOAA-20 had a fortuitous overpass, almost directly over Tinian at landfall. The Day Night Band Visible (0.7 µm) Imagery (with a full moon) and 11.45 µm infrared imagery is shown below).

NOAA-20 VIIRS Day Night Band visible (0.7 µm) imagery and I05 infrared (11.45 µm) imagery, 1551 UTC on 24 October 2018 (Click to enlarge)

CIMSS helps manage a Direct Broadcast (DB) antenna at the National Weather Service on Guam, and that antenna received both NOAA-20 and GCOM data as the eye was over, or close to, Tinian.  Microwave imagery from The Advanced Microwave Scanning Radiometer 2 (AMSR-2) on JAXA’s GCOM satellite, below, (courtesy Kathy Strabala, CIMSS) at 36.5 GHz and 89.0 GHz, reveals cloud and rainband structures that infrared imagery cannot.  In particular, the 89.0 GHz imagery suggests the formation of an outer eyewall ouside the very compact inner eye.  This typically is the start of an eyewall replacement cycle.

GCOM AMSR-2 imagery at 36.5 and 89.0 GHz, 1601 UTC on 24 October 2018 (Click to enlarge)

The DB antenna also processed data from NOAA-20, the same overpass as shown above, zoomed in over Tinian. The antenna is able to capture data over much of the western Pacific Basin, as the Day Night Band visible image shows below. A true color image from the previous overpass on Guam, 12 hours earlier, during daytime (0311 UTC on 24 October), is here.

NOAA-20 VIIRS Day Night Band visible (0.7 µm) imagery, 1544 UTC on 24 October 2018 (Click to enlarge)

Hurricane Walaka

October 1st, 2018 |

GOES-15 Infrared Window (10.7 µm) images [click to play animation | MP4]

GOES-15 Infrared Window (10.7 µm) images [click to play animation | MP4]

GOES-15 (GOES-West) Infrared Window (10.7 µm) images (above) showed the formation of a well-defined eye of Hurricane Walaka during a period of rapid intensification (ADT | SATCON) from 0000-2330 UTC on 01 October 2018; Walaka was classified a Category 5 hurricane as of the 02 October 00 UTC advisory. Walaka was moving over very warm water with Sea Surface Temperatures of 30ºC.

A 1536 UTC DMSP-16 SSMIS Microwave (85 GHz) image from the CIMSS Tropical Cyclones site (below) revealed a small eye (reported to be 20 nautical miles in diameter at 21 UTC).

DMSP-16 SSMIS (85 GHz) Microwave image [click to enlarge]

DMSP-16 SSMIS (85 GHz) Microwave image [click to enlarge]

A side-by-side comparison of JMA Himawari-8 and GOES-15 Infrared Window images (below) showed Walaka from 2 different satellite perspectives — the superior spatial resolution of Himawari-8 (2 km, vs 4 km for GOES-15) was offset by the much larger viewing angle. Cloud-top infrared brightness temperatures were -80ºC and colder (shades of violet) from both satellites early in the animation, but warmed somewhat into the -70 to -75ºC range by 00 UTC on 02 October.

Infrared Window images from Himawari-8 (10.3 µm, left) and GOES-15 (10.7 µm, right) [click to play animation | MP4]

Infrared Window images from Himawari-8 (10.3 µm, left) and GOES-15 (10.7 µm, right) [click to play animation | MP4]

===== 02 October Update =====

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Walaka remained classified as a Category 5 hurricane until the 15 UTC advisory on 02 October, when it was assigned Category 4 status after some weakening as a result of an overnight eyewall replacement cycle. A toggle between NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images (above; courtesy of William Straka, CIMSS) showed the storm at 1240 UTC or 2:40 am local time.

GOES-15 Infrared Window (10.7 µm) images (below) showed the northward motion of Waleka. Given that the storm was forecast to pass very close to Johnston Atoll, the US Coast Guard was dispatched to evacuate personnel on Johnston Island.

GOES-15 Infrared Window (10.7 µm) images; the white circle shows the location of Johnston Atoll [click to play animation | MP4]

GOES-15 Infrared Window (10.7 µm) images; the white circle shows the location of Johnston Atoll [click to play animation | MP4]

The MIMIC-TC product (below) showed the eyewall replacement cycle during the 0000-1445 UTC period.

MIMIC-TC morphed microwave product [click to play animation]

MIMIC-TC morphed microwave product [click to play animation]

Around 1830 UTC, a toggle between GOES-15 Infrared (10.7 µm) and GPM GMI Microwave (85 GHz) images (below) showed a small eye, with evidence of a larger outer eyewall suggesting that another eyewall replacement cycle was taking place.

GOES-15 Infrared Window (10.7 µm) and GPM GMI Microwave (85 GHz) images [click to enlarge]

GOES-15 Infrared Window (10.7 µm) and GPM GMI Microwave (85 GHz) images [click to enlarge]