Overlapping 1-minute Mesoscale Domain Sectors provided GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images at 30-second intervals (above), which included plots of time-matched (+/- 3 minutes) SPC Storm Reports — showing thunderstorms that produced a few tornadoes, hail as large as 1.75 inches in diameter and wind gusts to 76 mph across parts of the Florida Panhandle (and adjacent far southwestern Georgia) on 27 April 2023. Pulsing overshooting tops exhibited infrared brightness temperatures as cold as -82ºC (violet pixels).

The coldest overshooting tops were associated with experimental CLAVR-x Cloud Top Height of 16.64 km (54593 ft), vs. 47866 ft (14.59 km) with the Operational CONUS sector Cloud Top Height product (below). The CLAVR-x derived GOES cloud products produced at CIMSS are at full 2 km spatial resolution — in contrast to some of the Operational cloud products, including Cloud Top Height, which are still disseminated at reduced resolutions of 10 km over the CONUS sector (although the Cloud Top Height spatial resolution is 4 km for the Mesoscale Domain Sector).

View only this post Read Less

There are different RGBs available to monitor volcanic signatures within a cloud, and three common ones are shown above. The Dust RGB and the Ash RGB use identical channels/channel differences that are scaled differently. All three RGBs (here is the The SO₂ RGB Quick Guide) include Band 11 information; Band 11 detects radiation in the part of the electromagnetic spectrum that is sensitive to absorption by SO₂. For the Sheviluch eruption (described in blog posts here and here) that occurred just at the beginning of this animation above, the SO₂ signal — bright yellow in the SO₂ RGB — persists the longest. That, of course, will not be the case with every eruption; that’s why one must use more than one product to monitor an eruption.

Note that “Keep Out Zones” are apparent in the imagery above as regions of no data around 1440 UTC, when the Himawari-9 imager is turned off when it is pointing a little too closely towards the Sun.

---

Himawari-9 imagery in this blog post are courtesy of JMA. The Full-Disk HSD data were processed into RGB images using geo2grid.

---

By 14 April, much of the signal has shifted eastward out of Himawari-9’s field of view. The animation below, from GOES-18, shows the three RGBs from 0000 UTC on 14 April through 0000 UTC on 20 April. The signal of enhanced SO2 in particular has remarkable staying power.

View only this post Read Less

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (above) include plots of time-matched (+/- 3 minutes) SPC Storm Reports — which showed thunderstorms that produced hail as large as 4.50 inches in diameter and wind gusts to 63 mph across North Texas on 26 April 2023.  Cloud-top infrared brightness temperatures were as cold as -81ºC at 2328 UTC (violet pixels), and Above-Anvil Cirrus Plumes (reference | VISIT training) were evident with the 2 more dominant supercell thunderstorms.

1-minute GOES-16 Visible and Infrared images with/without an overlay of GLM Flash Extent Density (below) revealed that the easternmost supercell thunderstorm tended to exhibit a bit more lightning activity. These severe thunderstorms developed just to the north of a quasi-stationary frontal boundary that was draped across North Texas.

GOES-16 Visible and Infrared images at 0022 UTC (above) showed an Above-Anvil Cirrus Plume (AACP) particularly well — at that time there was a 20ºC infrared brightness temperature difference between the cold overshooting top (-76ºC, darker black enhancement) and the downwind AACP (-56ºC, brighter green enhancement). A warmer AACP was consistent with warming temperatures above the local tropopause, as seen in a plot of rawinsonde data (source) from Fort Worth, Texas at 0000 UTC (below).

View only this post Read Less

With Spring comes the beginning of fire season for the United States, and with the help of satellite data, model output can provide information about future smoke and fires.

Fire weather outlooks are available from the NOAA Storm Prediction Center (SPC). These are qualitative categorical outlooks similar to those the SPC issues for severe weather. Also provided by NOAA is the High-Resolution Rapid Refresh (HRRR) Smoke model, which forecasts smoke transport using a variety of inputs including radiances from GOES, MODIS, and VIIRS.

Both of these products are available in RealEarth, making it handy to gauge smoke and fire events across the United States and plan for future smoke and fire events. There are currently ‘elevated’ and ‘critical’ areas of New Mexico designated by the fire weather categorical outlooks. RealEarth is also available for Android and iOS.

View only this post Read Less