Typhoon Hagibis south of Japan

October 11th, 2019 |

Himawari-8 Clean Window Infrared (10.41 µm) imagery every 2.5 minutes, from 1429 UTC to 1932 UTC on 11 October 2019. Imagery courtesy JMA (Click to animate)

Himawari-8 Advanced Himawari Imagery (AHI) from the ‘Target’ sector, above, show a strong albeit asymmetric storm south of Ise Bay and southwest of Tokyo Bay. Clean window infrared (10.41 µm) imagery, above, shows a compact eye that is cooling with time, suggesting weakening (and/or becoming more cloud-filled). Most of the cold clouds in the storm are north of the center, a distribution that suggests shear.  However, the storm is still producing strong convection that is wrapping around the eye. By the end of the animation, at 1929 UTC, the eye is no longer distinct.  This toggle compares the 1432 and 1929 UTC images.  A decrease in storm cloud-top organization near the eye is apparent.

Data from the CIMSS Tropical Page at 1530 UTC on 11 October, shown below in a stepped animation, show southerly shear that will increase with time over the storm as it moves towards Japan. Microwave imagery (85 GHz) also suggest a sheared storm, as does the infrared imagery.  Low-level water vapor imagery (7.3 µm), here), shows dry air (yellows in the color enhancement chosen) prevalent over the southern half of the storm.  These data suggest that a slow extratropical transition is underway.

Past and Predicted path of Hagibis, Observed Shear at 1500 UTC, the latest 85 GHz image over the storm, and Infrared window imagery at 1530 UTC. (Click to enlarge) All imagery from the CIMSS Tropical Page.

The Airmass RGB image over the Pacific Basin, (animation), (from this site at CIRA) also shows dry air consistent with a transition from tropical to extratropical. The zoomed-in image of the Airmass RGB, below, from Real Earth, shows the dry air as shades or orange/copper southwest of the storm, in contrast to the deep tropical moisture, feeding into the storm from the south, that is greener.

Airmass RGB from Himawari-8 Data, 1630 UTC on 11 October 2019

The Joint Typhoon Warning Center has the latest on Hagibis. A projected path valid at 1500 UTC 11 October is here.

Suomi NPP overflew Hagibis at 1639 UTC on 11 October. The toggle below shows the Day Night Band (0.7 µm Visible imagery) and the 11.45 µm infrared imagery from the Visible Infrared Imaging Radiometer Suite (VIIRS) Instrument.  A larger-scale view of the Day Night Band is here.  (Imagery courtesy William Straka, CIMSS)

Suomi NPP Day Night Band Visible Imagery (0.7 µm) and Window Infrared (11.45 µm) from VIIRS, 1638 UTC on 11 October 2019 (Click to enlarge)

ACSPO SSTs from VIIRS in AWIPS

October 10th, 2019 |

ACSPO SSTs (range from 41 F to 68 F or 5 C to 20 C) at 0818 UTC on 10 October 2019 (Click to enlarge)

SSEC/CIMSS is producing Advanced Clear Sky Processor for Ocean ACSPO Sea Surface Temperatures (SSTs) from Direct Broadcast data received in Madison. (Here is a blog post on ACSPO SSTs in Guam) The example above shows Great Lakes water temperatures around 0800 UTC on 10 October 2019. The example below shows SSTs computed from the Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi-NPP and NOAA-20 around Vancouver Island from 8 through 10 October (a period when the Pacific Northwest was enjoying a spate of clear skies that are necessary for ACSPO SST computation).  These data are available via LDM feed.

ACSPO SSTs (range from 41 F to 68 F or 5 C to 20 C) from 8 October through 10 October 2019 (Click to enlarge)

Super Typhoon Hagibis in the West Pacific Ocean

October 7th, 2019 |

Himawari-i8

Himawari-8 “Clean” Infrared Window (10.4 µm) images [click to play animation | MP4]

JMA Himawari-8 “Clean” Infrared Window (10.4 µm) images (above) showed the pinhole eye of Super Typhoon Hagibis as it rapidly intensified to a Category 5 storm (ADT | SATCON) by 12 UTC on 07 October 2019. Hagibis exhibited some trochoidal motion and variations in forward speed as it approached the Northern Mariana Islands, eventually moving just south of the small uninhabited island of Anatahan (north of Saipan, station identifier PGSN) around 15 UTC.

A toggle between VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP (below) showed the eye just west of Anatahan.

VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP (credit: William Straka, CIMSS) [click to enlarge]

VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP (credit: William Straka, CIMSS) [click to enlarge]

During the period 06 October/2014 UTC to 07 October/0714 UTC, Himawari-8 “Red” Visible (0.64 µm) images (below) showed the initial period of rapid intensification, during which Hagibis developed a well-defined pinhole eye.

Himawari-8 "Red" Visible (0.64 µm) images [click to play animation | MP4]

Himawari-8 “Red” Visible (0.64 µm) images [click to play animation | MP4]

Hagibis was moving over warm West Pacific water with high values of Sea Surface Temperature and Ocean Heat Content — the storm was also moving through an environment characterized by low deep-layer wind shear.

===== 08 October Update =====

Himawari-8 "Clean" Infrared Window (10.4 µm) images [click to play animation | MP4]

Himawari-8 “Clean” Infrared Window (10.4 µm) images [click to play animation | MP4]

2.5-minute rapid scan Himawari-8 Infrared images (above) showed Hagibis during an eyewall replacement cycle (erosion of the small inner eye, with the subsequent formation of a larger-diameter eye). The small inner eyewall could be seen rotating within the larger eye as this transition was taking place. Once the eyewall replacement cycle was completed, Hagibis re-intensified to a Category 5 storm at 18 UTC.

VIIRS Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 (below) displayed the eye and eyewall region of the Category 4 storm.

VIIRS Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 [click to enlarge]

VIIRS Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 (courtesy of William Straka, CIMSS) [click to enlarge]

A toggle between VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1556 UTC (below) provided a nighttime view of Hagibis.

VIIRS Day/Night Band (0.7 µm ) and Infrared Window (11.45 µm) images at 1556 UTC [click to enlarge]

VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1556 UTC (courtesy of William Straka, CIMSS) [click to enlarge]

Aircraft dissipation trails over southern Wisconsin and northern Illinois

October 6th, 2019 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (above) revealed a series of aircraft “dissipation trails” drifting northeastward across southern Wisconsin and northern Illinois on 06 October 2019. These cloud features were caused by aircraft that were either ascending or descending through a layer of cloud composed of supercooled water droplets — cooling from wake turbulence (reference) and/or particles from jet engine exhaust acted as ice condensation nuclei to cause the small supercooled water droplets to turn into larger ice crystals (many of which then often fall from the cloud layer, creating “fall streak holes“).

A comparison of Suomi NPP VIIRS Visible (0.64 µm), Near-Infrared (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images (below) helped to confirm the presence of ice crystals within the aircraft dissipation trails: a darker appearance in the 1.61 µm image (since ice is a strong absorber of radiation at that wavelength), and a colder (brighter white) signature in the 3.74 µm image. In the enhancement applied to the 3.74 µm and 11.45 µm images, colors are applied to infrared brightness temperatures of -30ºC and colder — and the shades of yellow represent cloud-top brightness temperatures in the -30 to -39ºC range.

Suomi NPP VIIRS Visible (0.64 µm), Near-Infrared (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm), Near-Infrared (1.61 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Several of the “fall streak” clouds were seen in time-lapse videos of west- and east-facing AOSS rooftop cameras (below).

Time lapse of west-facing AOSS rooftop camera images [click to play YouTube video]

Time lapse of west-facing AOSS rooftop camera images (courtesy of Pete Pokrandt, AOSS) [click to play YouTube video]

Time lapse of east-facing AOSS rooftop camera images [click to play YouTube video]

Time lapse of east-facing AOSS rooftop camera images (courtesy of Pete Pokrandt, AOSS) [click to play YouTube video]