RADARSAT-2 overflew the Samoan Islands shortly after sunset on 4 March 2023, as shown above. The NRCS and derived wind fields show light winds over the entire region. The toggle below show Metop-B and Metop-C ASCAT winds between 0800 and 1000 UTC on 5 March. Those instruments also detect light winds.

MIMIC Total Precipitable water fields, below, from 0000 UTC 04 March through 0000 UTC 06 March, show the Samoan islands north of an active storm path (cyclone Kevin moves from 170^oE to 170^oW during the animation, the remains of cyclone Judy move from 170^oW to 150^oW during the animation), and south of a region of moisture moving in slowly from the east.

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Only 2 days after Cyclone Judy, Cyclone Kevin traversed the far southern islands of Vanuatu on 03 March 2023 — and due to a favorable environment of low deep-layer wind shear coupled with warm Sea Surface Temperature, the storm reached Category 3 Intensity at 1800 UTC. Kevin displayed a distinct eye, with feeder bands wrapping into the storm center, in DMSP-17 SSMIS Microwave (85 GHz) imagery at 1848 UTC (below).

Kevin continued to strengthen during the day, reaching Category 4 intensity (130 knot wind speed) at 0000 UTC on 04 March (SATCON) — JMA Himawari-9 Infrared Window (10.4 µm) images (below) showed a well-defined eye, surrounded by cloud-top infrared brightness temperatures in the -80ºC to -90ºC range.

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GOES-16 (GOES-East) Air Mass RGB images (above) include plots of time-matched Local Storm Reports — which showed some of the impacts of a deep low pressure system (surface analyses) that moved northeastward across the Tennessee and Ohio Valley on 03 March 2023. 

A Mesoscale Domain Sector was positioned over part of that area — and 1-minute GOES-16 “Red” Visible  (0.64 µm) images (below) included time-matched (+/- 3 minutes) plots of SPC Storm Reports. Tornadoes, wind gusts to 77 mph and hail of 1.00 inch diameter were reported.

This storm also set new all-time record low pressures at a few locations.

RECORD LOW PRESSURES: Several long-standing all-time low-pressure records have been set today as a result of a very strong storm system centered over the Lower Ohio River Valley. See the graphic below to learn more: pic.twitter.com/J97bXysNnY

— NWS Weather Prediction Center (@NWSWPC) March 4, 2023

The lowest pressure record (977.5 hPa) was set at Evansville, Indiana — a plot of their weather conditions is shown below.

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The Synthetic Aperture Radar instrument on RADARSAT Constellation Mission-2 (RCM-2) satellite sampled the winds over the western half of Cyclone Judy at 0700 UTC on 2 March 2023, as shown in the toggle above that also includes the GOES-18 Band 13 Clean Window infrared (10.3 µm) imagery. Peak winds are 41 m/s in the southern eyewall, and strongest winds are in general in the southern part of the eyewall (as shown in this analysis). The coldest cloud tops also are over the southern part of the storm’s eyewall. (Previous blog post on Judy is here)

The toggle below compares the derived winds with the Normalized Radar Cross Section (NRCS) imagery, taken from this website. Additional information on the SAR wind distributions around the eye of Judy are available at the SAROPS Tropical Cyclone Judy website.

The mp4 animation below shows Cyclone Judy in the hours bracketing the SAR overpass above. One overshooting top in the eyewall is apparent just as the sun set on the storm at 0630 UTC. Total Precipitable Water fields from MIMIC-2 (link), below, show Judy moving southeastward — followed by Cyclone Kevin. For more information on these two storms, refer to the Joint Typhoon Warning Center or the Fiji Tropical Cyclone Warning Center or the CIMSS Tropical Website.

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