Many Cooperative Institute for Meteorological Satellite Studies tropical cyclone intensity estimation products were referenced by the National Hurricane Center during Hurricane Lowell, which passed just west of the Hawaiian Islands. These mentions include: upgrading Lowell to a Category 5 hurricane: “The subjective Dvorak and objective UW-CIMSS estimates have risen since the prior advisory, with a T7.0/140 kt classification from JTWC along with recent AiDT and D-PRINT estimates around 140 kt. Based on these developments, Lowell has become a Category 5 hurricane with an initial intensity of 140 kt.” and justification for differing from aircraft reconnaissance data: “An Air Force Reserve Hurricane Hunter aircraft completed a mission in Lowell a few hours ago and measured peak 700-mb flight-level winds of 114 kt, which typically equates to an intensity of 100-105 kt. However, dropsonde data from the plane also indicated that the central pressure (943 mb) was a bit lower than previously estimated. For that reason, Lowell’s currently intensity is held at 110 kt, which is also very close to the latest UW-CIMSS DPRINT and SATCON estimates.” Other mentions include: a discussion of increased satellite intensity estimates: “This impressive structure has led to an increase in the satellite intensity estimates, with JTWC and HFO recently providing T6.5/127 kt Dvorak estimates. Meanwhile, the latest AiDT and D-MINT objective estimates from CIMSS have climbed above 130 kt. Since the satellite presentation continues to improve and the eye of Lowell has warmed during the past couple of hours, the initial intensity is raised to 135 kt.” And a comparison of intensity numbers: “The latest Dvorak Current Intensity numbers from HFO and JTWC are 6.5/127 kt, and the UW-CIMSS DPRINT estimate, which has been tracking well with Lowell’s recent intensity changes, is around 130 kt.”

The Cooperative Institute for Meteorological Satellite Studies (CIMSS) Satellite Blog was updated with the following posts: ”Eruption of Anak Krakatau in Indonesia” (Sep. 5-6) and “Hurricane Lowell passes over the far western Hawaiian Islands” (Sep. 8).

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  Figure: JMA Himawari-9 True Color RGB image at 0000 UTC on Sep. 5, 2026 -- showing the signatures of middle-tropospheric volcanic ash (shades of brown) and brighter-white pulses of upper-tropospheric volcanic clouds (a mixture of water vapor, ash and SO2) following a major eruption of Anak Krakatau in Indonesia.
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  Figure: GOES-18 Infrared Window image at 0630 UTC on Sep. 8, 2026 -- showing Category 2 Hurricane Lowell as it was beginning to pass near the far western Hawaiian islands of Ni'ihau and Kaua'i.