Sentinel-1A overflew the central Hawai’ian islands near sunset on 10 April 2023, and the SAR data collected are shown above. Data are also available online at this website. The toggles below compare wind speed from that website (04:39:48 and 04:40:19 from south to north) with Normalized Radar Cross Section fields (04:39:48 and 04:40:19). The character of the wind fields are much different north and south of the Hawai’ian Island chain, with the southern winds showing marked funneling between islands, and smaller regions of lighter winds in the lee of the islands.

The Slider below shows the SAR wind field north of Hawai’i with the brightened GOES-18 Visible imagery. There is excellent correspondence between local wind maxima and cloud features (presumably showers). Sometimes, the strongest SAR winds are associated with misinterpretation of strong reflection from cloud ice by the SAR Wind algorithm; when that happens, ‘feathery’ structures are usually apparent in the NRCS field. There is little evidence of that happening in the SAR winds above.

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Sentinel-1A has a 12-day repeat cycle, so the same domain as above should have been duplicated 12 days earlier, late in the day on 29 March (or around 0400 UTC on 30 March). The toggle below compares the data at 04:39:37 on 30 March and 04:39:38 on 11 April. This scene should be repeated on 23 April this month. ESA does provide kml files that show when the next collections will happen (link).

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JMA Himawari-9 Ash RGB images created using Geo2Grid (above) showed the volcanic plume —  which included a violent eruptive pulse that began at 0540 UTC on 07 April — from Bezymianny on the Kamchatka Peninsula of Russia during 06-07 April 2023. Signatures of ash (shades of pink to violet) were evident, along with the signature of SO2 mixed with ash (brighter shades of yellow) associated with the violent eruptive pulse.

A closer view of the volcanic cloud produced by the violent eruptive pulse is shown below, using Himawari-9 True Color RGB and Ash RGB images.

A Himawari-9 Ash Height retrieved product from the NOAA/CIMSS Volcanic Cloud Monitoring site (above) indicated that the violent eruptive pulse reached heights 10-12 km — and Ash Loading was high within that portion of the volcanic cloud (below).

GOES-18 (GOES-West) “Red” Visible (0.64 µm) images from the CSPP GeoSphere site (below) provided an oblique view of the cloud produced by the violent eruptive pulse.

GOES-18 Ash RGB images (above) also showed signatures of both ash (shades of pink to violet) and mixed SO2/ash (brighter shades of yellow) as the volcanic plume moved over the far western Aleutian Islands. An aviation Volcanic Ash Advisory was issued, stating that ash was possible between the surface and 40,000 feet (12 km), moving to the east-southeast at 100 knots (below).

In a larger-scale view of GOES-18 Ash RGB images (below) the brighter yellow SO2/ash feature could be followed for several more hours as it moved across the western and central Gulf of Alaska.

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The NOAA/CIMSS ProbSevere team created a tool to help forecasters monitor the time tendency of lightning potential at a static point. The static points in the map below are mostly civilian airports and army airfields throughout the U.S. From the ProbSevere LightningCast website, a user can toggle on the “Lightning meteograms” layer from the menu on the left (Figure 1). The user can then click a location (red dots) and finally click the link in the pop-up window. This will bring up a new website with different time series (Figure 2 [static link]).

From this page, a user can quickly see how the probability of lightning has been changing (computed by LightningCast), as well as the observed lightning tendencies from GOES-East and GOES-West GLM, and Earth Networks Inc™. LightningCast probabilities are computed on the 5-minute and 1-minute scans for both GOES-East and GOES-West (when applicable). The 1-min scans will be displayed when the location is covered by a mesoscale sector. Users can change the location of meteograms (top left) as well as the time frame (top right). Data from recent days will be archived. The flash rates from GLM and ENI are aggregated within 5- and 10-mile radii of the location and within the previous 5 minutes.

Forecasters can use this to monitor lightning for aviation purposes or nearby large outdoor events. For instance, forecasters are surely monitoring for lightning at the Masters Golf Tournament in Augusta, GA today. LightningCast probabilities have been steadily increasing for nearly an hour, and lightning was observed within 5 miles of Augusta Regional airfield (Figure 3). Augusta Regional is about 10 miles southwest of Augusta National Golf Course.

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A sequence of 1-minute Mesoscale Domain Sector GOES-18 (GOES-West) images from all 16 ABI spectral bands (above) displayed reflectance and/or thermal signatures of the SpaceX Falcon-9 rocket booster as the Intelsat-40e/TEMPO Mission was launched from Cape Canaveral Space Force Station in Florida at 0430 UTC on 07 April 2023.

A subtle reflectance was even detected in Band 02 (“Red” Visible) imagery at 0430 UTC and 0431 UTC (below).

A stepped sequence of images from spectral bands 02-06 at 0430 UTC is shown below.

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