Target Sector (2.5-minute interval) JMA Himawari-9 AHI Red Visible (0.64 µm) and Clean Infrared Window (10.4 µm) images (above) showed Invest 90P as it intensified to become Tropical Cyclone Kirrily over the Coral Sea on 23-24 January 2024. Visible images showed multiple exposed low-level circulation centers, while Infrared images showed that deep convection was mainly developing west of the storm center.

Himawari-9 Infrared Window (11.2 µm) images from the CIMSS Tropical Cyclones site (below) showed that Tropical Cyclone Kirrily was moving through an environment of low deep-layer wind shear (in contrast to the high values of shear that were affecting Invest 90P on 20 January).

===== 25 January Update ====

2.5-minute Himawari-9 Visible and Infrared images (above) showed Cyclone Kirrily as it approached the coast of Queensland, Australia — making landfall near Townsville (YBTL) around 1200 UTC on 25 January 2024.

A plot of surface report data from Townsville (below) depicted a pressure minimum from 1120-1200 UTC (during landfall), with a maximum wind gust of 50 kts at 0942 UTC (prior to landfall).

Several hours prior to landfall, the Jason-3 satellite was detecting altimeter Significant Wave Heights (the average of the highest 1/3^rd of the wave distribution.) up to 20.34 ft off the coast of Queensland at 0422 UTC (below).

Around the time of landfall, ASCAT winds from Metop-B and Metop-C (below) were in the 40-50 knot range near the coast.

A toggle between daytime (pre-landfall) and nighttime (post-landfall) Suomi-NPP VIIRS Day/Night Band (0.7 µm) images is shown below.

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A cold snap in mid-January 2024 (Click here to see a High/Low temperature chart for Aurora Illinois from this site) led to rapid ice formation on the Kankakee River southwest of Chicago, and an ice jam with ice jam flooding subsequently developed. The map above shows different flood gauge records along the Kankakee (source). Flooding is occurring near the Wilmington IL flood gauge. The toggle below illustrates the small size of the Kankakee River relative to the 375-m VIIRS pixel size used in the Flood Product (available here)! Flood detection from an ice jam will be a challenge. (Editor’s note: I regret not clearing my Google search/cookies before creating this imagery, and shortly after searching for dog kennels)

The animation below compares views on 11 January (when the ground was mostly bare), 13 January (after a snow storm and cold snap) and 14 January 2024 (12 January was a cloudy day). The domain is larger than shown in the toggle above. Note the change from bare ground on the 11th to snow-covered on the 13th, and the change from open water on the 11th to ice on the 14th. A single red pixel is present near Wilmington on the 13th; however, the river was not above flood stage at that time.

What happened from 14-20 January, specifically as the river exceeds flood stage on the 16th? The small river appears to be mostly ice-covered (cyan), with occasional water detections. There are more open water detections downstream of Lorenzo IL, where the river gauge does not suggest flood conditions. An important question would be: are the water detections close to Wilmington showing water associated with the ice jam? That’s a hard question to answer with this product.

Views from 19-21 January 2024, show, so more of the same. Ice cover with occasional open-water detection.

On 22-23 January, clouds prevented VIIRS flood detection. A news story on the 22nd (link) suggests the ice jam effects are lessening, in part because of the diversion of warm water from a power plant.

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Sentinel-2 imagery from 20 January 2024 (link) can be matched to drone images show at this news link, as shown in the toggle below. In this region near the I-55 bridge, water has no overflown the river banks.

Thanks to Sarah Marquardt, NWS MKX, for alerting us to this event. A flood warning remains in effect for this event through 29 January 2024.

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Sentinel-1A overflew this region at 2349 UTC on 23 January 2024, and the SAR Ice image is shown below. Cyan is ice, blue is open water. The Kankakee River is still largely ice-covered, but with some fracture ice. The Service Hydrologist at the Chicago NWS Office reports that fractured and jumped ice is present (although not shown in the image below) from the island in the Kankakee River upstream to the I-55 bridge and beyond.

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Damaging waves hit the Marshall Islands on 19 January 2024, causing considerable damage, and the northern shores of American Samoa on 22 January 2024, leaving behind considerable debris, as shown below (photos courtesy NWS Pago Pago).

The waves could be tracked using Altimetric data as viewed at this NOAA/NESDIS website; data for the globe and also data around the Marshall Islands were saved from that website and shown below. A second website (that contains data over South Pacific around Samoa, which data are routinely taken from the NOAA/NESDIS website and stitched into a larger field) was used to save imagery around American Samoa as shown below. Plots at these websites show Significant Wave Height, that is, the mean of the highest 1/3rd of the waves. The global animation, below, centered on the Pacific, shows a region of higher waves moving southward through the western Pacific; stars show the location of the Marshall Islands (20 January) and American Samoa (22 January), at the approximate time of the waves’ arrival at those locations.

The animation below is zoomed in over the Marshall Islands, and covers 0^o to 20^oN Latitude, 180-150^oE Longitude. Note the southward progression of progressively larger waves through the animation. The purple box is the approximate location of Roi-Namur, the island where the damage discussed in the Army Times article above occurred.

The animation below shows American Samoa (highlighted in the Green Box). Wave heights increase from around 7 to 11 feet in advance of the large waves’ arrival on Tutuila and Manu’a. A High Surf warning was issued by the forecast office in Pago Pago.

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What caused these waves? Forecast model output (courtesy Eric Lau, NWS PRH), below, shows hurricane-force winds (in yellow, between 160^o and 170^oE longitude) generated by a potent extratropical cyclone to the east of Japan. The strong winds are present for about 24 hours, and the region of strongest winds translates with the predicted wind direction. The similarities between the wind direction and the motion of the speed maximum suggest that dynamic fetch may have been responsible for the extraordinary waves.

WPC OPC analyses, below, (also from Eric Lau) show the rapid development of the storm from 1003 mb on 1200 UTC.16 January 2024 to 964 mb on 1200 UTC/17 January 2024. The storm started to weaken starting at 1200 UTC/18 January 2024.

What did the satellite data look like during this time period? The airmass RGB animation, below, (created from geo2grid using Himawari-9 data supplied by JMA), shows the development of a strong, but not necessarily unusually strong, storm. Recall that the strongest winds were predicted to be between 160 and 170^oE, from 1200 UTC on the 17th to 1800 UTC on the 18th.

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A toggle between NOAA-20 VIIRS Day/Night Band and Infrared Window images valid at 0827 UTC (2:27 AM local time) on 22 January 2024 (above) showed an opening of the Kivalliq Polynya along the northwest coast of Hudson Bay — which was the result of a period of strong offshore winds (Arviat Airport CYEK observations), which tend to push thicker first year ice away from the Nunavut and Manitoba coast. With cold arctic air blowing across the polynya, a layer of thin ice quickly begins to grow where the thicker ice was displaced.

During the following daytime hours, a comparison of NOAA-20 VIIRS Visible, Near-Infrared and Infrared Window images valid at 1820 UTC (below) displayed the lower reflectance of the polynya ice in Visible imagery (which was also evident, via reflected moonlight, in the earlier Day/Night Band image) — along with horizontal convective rolls in the Near-Infrared image, highlighting bands of blowing snow moving east-southeastward across Hudson Bay.

In a toggle between NOAA-20 VIIRS Visible and ATMS MiRS Sea Ice Concentration images (below) the Sea Ice Concentration within the polynya was as low as 88% (darker red pixels).

Suomi-NPP VIIRS Ice Surface Temperature (IST) and Sea Ice Concentration (SIC) products (below) displayed gradients in those parameters within the polynya, with warmer IST and lower SIC values closer to the coast. The IST gradient was more notable, being about 10 K warmer near the coast.

A sequence of GOES-16 True Color RGB images (source) from 1540-2030 UTC on 21 January and 22 January (below) showed a widening of the Kivalliq Polynya during that 2-day period.

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