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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The recent bouts of severe weather (See this blog post about the 31 March outbreak, or this one about the 4 April outbreak) over the central United States mean an opportunity to compare Numerical Model output from models that are initialized with temperature/moisture profiles derived from Polar Hyperspectral Soundings (using both infrared and microwave data from CrIS/ATMS or IASI/AMSU/MHS) to models that have not assimilated such data. Does the addition of the observations of temperature and moisture profiles observed by NOAA-20/NOAA-21 or MetopB/MetopC lead to a better prediction of convective weather? As happened in 2022, this Polar Hyperspectral Modeling System (PHSnMWnABI, or just PHS for short) will be demonstrated at SPC’s Hazardous Weather Testbed. The blog post will show a few examples of differences between PHS-enhanced modeling output, and a separate modeling system not so enhanced.

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Significant Tornado Parameter (STP) can be computed from HRRR model output and from PHS/WRF model output, and that field, overlain with severe weather reports, is shown below at hourly intervals for the 31 March – 1 April severe weather event. There is good correpondence between the severe weather reports and the STP fields, moreso especially with PHS-enhanced WRF model over Iowa and Illinois at 2100, 2200, 2300, 0000 and 0100 UTC. (These fields show average values of 9 separate forecasts valid at the time shown, that is, the average of a 1-h forecast, a 2-h forecast, a 3-h forecast…, and a 9-h forecast valid at the time shown).

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Consider the toggle below that compares HRRR model output (without PHS input) and WRF model output (with PHS input). There is a pronounced difference in the predicted radar reflectivity in this 3-h forecast to the west of Chicago (NWS WFO outlines are shown on that map). The 1700 UTC radar, below (source), shows better agreement with the PHS model, although an argument could be made that the PHS model is overpredicting the precipitation on this day.

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A comparison of the average STP from different forecasts enhanced by PHS observations and forecasts that do not assimilate PHS data is shown below for the same event, but at 0000 UTC on 5 April 2023. (Here’s the same figure for 1500 UTC on the 4th, and 0900 UTC on the 5th). In general, STP values are greater in the WRF run that starts with assimilated moisture and temperature observations from Hyperspectral Soundings.

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More results from this modeling system will be shown in the coming weeks. Imagery in this blog post is courtesy Qi Zhang, CIMSS. Model output from this system is available online here.

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