A period of high-based convection to the east and northeast of Hawaii was producing occasional lighting on 3 June 2024, as shown in the animation above. LightningCast Probabilities plotted show values around 50%, and lightning is occurring. Note that the Flash Extent Density colorbar has been modified to have a maximum value of only 8.

The convection is creating a signal in the CIMSS Turbulence product, shown below in imagery from this website. The animation below shows the contours of the probability of Moderate Or Greater (MOG) Turbulence to the northeast of Hawaii. The animation below also shows water vapor imagery as a greyscale, from which you can infer the upper-level low-pressure system over the Hawaiian Islands that is helping to force the thunderstorms.

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NOAA-20 overflew the region at around 1200 UTC on 3 June, and some NUCAPS soundings in the region are shown below. They uniformaly show a moist boundary layer capped by a stable layer. The mid-troposphere above that cap shows steep lapse rates and drying with height, that is, a convectively unstable atmosphere.

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High-based convection again developed between 0600 and 1200 UTC on 4 May 2024. The Hilo Sounding, below (source), showed a capped moist boundary layer with an unstable atmosphere above 700 mb.

NOAA-21 overflew the islands just before 0000 UTC as shown below. The NUCAPS soundings along the north shore of the big island of Hawai’i, are shown below. The profile north of 20 N is from 234344 UTC, the one south of 20 N is from 234312 UTC. The structures of the smooth NUCAPS profiles are similar to those of the Hilo rawinsonde shown above.

The animation below shows the LightningCast output (from this website) for the elevated convection between 0600 and 0800 UTC on 4 June 2024.

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Thanks to Robert Ballard, Science and Operations Officer (SOO) at WFO Honolulu for alerting us to this event. He notes the similarity to an event back in the year 2000, mentioned in this AFD. High-based thunderstorms such as these are rare in the tropics. They are decoupled from the tradewind cumulus: the thunderstorms are moving northward as the lower clouds move towards the west.

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5-minute PACUS Sector GOES-18 (GOES-West) Shortwave Infrared (3.9 µm) images (above) showed the thermal anomaly (heat signature) following the onset of an eruption of Kilauea on the Big Island of Hawai`i — which began around 1030 UTC on 03 June 2024. The peak 3.9 µm brightness temperature sensed at the eruption site was 134.2ºC at 1221 UTC, which was just a few degrees below the 137.88ºC saturation temperature of GOES-18 ABI Band 7 detectors.

GOES-18 Nighttime Microphysics RGB + daytime True Color RGB images from the CSPP GeoSphere site (below) displayed a narrow volcanic plume as it moved southwest; prior to sunrise, the Kilauea eruption thermal anomaly appeared as purple to blue pixels in the Nighttime Microphysics RGB images. Such volcanic plumes from similar Kilauea eruptions often contain varying amounts of SO₂.

GOES-18 SO₂ RGB images (below) did display a SO₂ signature (lighter shades of cyan), which more obvious immediately downwind of Kilauea but could also be seen streaming off the southwest coast of the Big Island.

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5-minute CONUS sector GOES-18 (GOES-West) Day Fire RGB, Shortwave Infrared (3.9 µm), Fire Temperature RGB and “Red” Visible (0.64 µm) images with overlays of the Fire Power and Fire Mask derived product (2 components of the GOES Fire Detection and Characterization Algorithm FDCA) (above) displayed signatures of the Corral Fire, which started around 2126 UTC on 01 June 2024 in far southern San Joaquin County (just south of Tracy, California).

A longer animation of GOES-18 Shortwave Infrared images (below) showed that the wind-driven grass fire quickly approached I-580 south of Tracy — forcing a portion of that Interstate highway (from the Alameda County line to the Stanislaus County line) to be closed for several hours on 02 June. Mandatory evacuations were also issued for parts of Tracy.

On the following morning, GOES-18 True Color RGB images from the CSPP GeoSphere site (below) revealed the dark burn scar of the Corral Fire — along with early-morning smoke plumes emanating from residual fire activity. Visibility restrictions due to smoke was one of the factors leading to the closure of I-580.

A Landsat-9 Natural Color RGB image at 1839 UTC on 02 June (below) provided a high-resolution view of the dark burn scar — which revealed that the Corral Fire crossed I-580 in two places.

A toggle between before (17 May) and after (02 June) Landsat-9 Natural Color RGB images is shown below.

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1-minute Mesoscale Domain Sector GOES-18 (GOES-West) “Clean” Infrared Window (10.3 µm) images (above) displayed areas of convection that moved across American Samoa on 01 June 2024 (1-minute imagery was requested by NWS Pago Pago to monitor the approach of thunderstorms, since they had issued a Flood Watch for the islands — and they lack radar coverage). Although there was a break in the convective activity midway through the period, Pago Pago did receive heavy rainfall from thunderstorms that began to arrive just as the 1-minute imagery was ending (decoded surface observations | METARs); those thunderstorms produced 0.62 inch of rainfall in 3 hours and 0.94 inch of rainfall in 6 hours (plot of surface report data).

A GOES-18 Infrared image showing a cold (-77.71ºC) thunderstorm overshooting top (not far to the west of American Samoa) at 0039 UTC on 02 June (below) included a cursor sample of the associated GOES-18 Cloud Top Height (50750 ft) and Rain Rate (1.90 in/hr) derived products at that location.

During a break in widespread cloud coverage across the region, the 10-minute GOES-18 Total Precipitable Water (TPW) derived product (in cloud-free regions) (below) showed a NW-to-SE oriented corridor of TPW values in the 2.0 to 2.2 inch range (lighter shades of violet) across the Samoan Islands.

However, the GOES-18 derived Total Precipitable Water values were less than the 2.62 inches obtained using rawinsonde data from Pago Pago, American Samoa at 0000 UTC on 02 June (below).

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