Severe thunderstorms traveled across the Southeast United States on Friday 2023-03-24. In Mississippi, at least 25 people were killed by tornado outbreak. Notable damage was experienced in Rolling Fork and Silver City, MS. The governor issued a state of emergency on Saturday, the following day.

NOAA’s Storm Prediction Center (SPC) issued a total of 32 tornado reports for the area on 2023-03-24. The Weather Forecast Office in Jackson, Mississippi warns of continued severe weather for the remainder of this week, through 2023-03-31.

RealEarth allows users to layer weather data products over one another, allowing you to view multiple weather products for a specific event. Here, we look at NEXRAD Radar Reflectivity with ProbSevere. ProbSevere is a product developed at UW – Madison CIMSS and aims to assist forecasters in determining areas that may experience severe weather, such as tornadoes. ProbSevere uses a combination of satellite data, ground-based data, and numerical weather models. It can be thought of as a probability of severe weather. Note the area of severity over Rolling Fork, MS at the 1:00 UTC timestamp in the animation below. A bright magenta outline surrounds the Rolling Fork area. This corresponds to when a tornado was spotted from the ground, around 8:00pm local time.

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.3 µm) images (above) include plots of time-matched (+/- 3 minutes) SPC Storm Reports during an outbreak of deadly tornadoes across parts of Mississippi, Alabama and Tennessee late in the day on 24 March 2023. The coldest thunderstorm tops exhibited infrared brightness temperatures around -70ºC (darker black enhancement).

A closer view of 1-minute GOES-16 Infrared images — with and without an overlay of GLM Flash Extent Density (above) — showed the supercell thunderstorm which produced a fatal EF4-rated long track tornado across far western Mississippi (with devastating effects in the cities of Rolling Fork and Silver City) from 0047-0208 UTC. The default infrared image enhancement was modified — setting the coldest end of the brightness temperature range at -92ºC — to help highlight the pulsing overshooting tops prior to and during the life cycle of this tornado-producing thunderstorm. The GLM Flash Extent Density also revealed a notable lightning jump (denoted by clusters of brighter white pixels) just prior to the development of the tornado. Lightning jumps frequently coincide with an increase in thunderstorm updraft intensity and/or updraft volume, preceding the onset of severe weather.

As the lightning jump was beginning, a toggle between GOES-16 GLM Flash Extent Density (FED) and Minimum Flash Area (MFA) at 0049 UTC (below) showed a maximum FED (bright white pixels) coincident with a minimum MFA (yellow pixels) along the Missouri/Mississippi border — the increasing number of lightning flashes within a smaller area was an indicator of the increasing potential of that thunderstorm producing severe weather.

A 2-panel animation of FED and MFA is shown below.

In a comparison of 1-minute GOES-16 Infrared images with the corresponding Cloud Top Temperature (CTT) derived product (below), the coldest CTT was -75ºC over the Louisiana/Mississippi border at 0047 UTC (the coldest 10.3 µm infrared brightness temperature during that time period was -73ºC).

According to a plot of Jackson, Mississippi rawinsonde data at 0000 UTC on 25 March (source), the coldest -75ºC Cloud Top Temperature value closely corresponded to an altitude near that of the calculated Most Unstable (MU) Maximum Parcel Level (MPL), which was 14 km (below).  

GOES-16 Total Precipitable Water, Lifted Index and Convective Available Potential Energy (CAPE) derived products (below) displayed a corridor of moisture and instability that extended north-northeastward across the Mississippi Valley ahead of an approaching cold front — which helped to create a favorable environment for the development of severe thunderstorms.

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JMA Himawari-9 Dust RGB images created using Geo2Grid (above) spanned the period from 2100 UTC on 20 March to 2350 UTC on 22 March 2023 — and showed a large area of dense blowing dust (brighter shades of magenta to pink) across parts of eastern Mongolia and northern/northeastern China (eventually crossing the China/Russia border). This Gobi Desert dust was lofted by strong winds produced by the tight pressure gradient between high pressure that was moving from Russia into western Mongolia and low pressure that was drifting from eastern Mongolia to northeastern China (KMA surface analyses: GIF | MP4).

A longer Dust RGB animation showed an additional pulse of blowing dust originating from the Taklamakan Desert on 19 March.

The Himawari-9 Split Window Difference product (below) showed that this blowing dust (brighter shades of yellow to cyan/blue to red) restricted the surface visibility to 1 mile or less at some sites during the period from 0000 UTC on 21 March to 0000 UTC on 23 March.

Himawari-9 True Color RGB images (above) showed the initial formation of blowing dust plmes (shades of tan) from 2210 UTC on 20 March to 0950 UTC on 21 March — which later became entrained into the aforementioned low pressure system (as it was centered over far northeastern China) during the period from 2210 UTC on 21 March to 0950 UTC on 22 March (below). An animation which combines these 2 daytime periods (20-21 March, and 21-22 March) is available here.

Similar cases of dust entrainment into the circulation of a midlatitude cyclone in this region were documented in blog posts from May 2021 and May 2019.

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This blog post reported on the addition of data from the AOML Direct Broadcast site in Miami to data from the SSEC/CIMSS Direct Broadcast ftp site. Now, data from the Direct Broadcast site in San Juan, Puerto Rico, have also been added, allowing imagery to extend all the way into central Brazil! These images are available at the CIMSS Direct Broadcast ftp site for Suomi NPP (https://ftp.ssec.wisc.edu/pub/eosdb/npp/) and for NOAA-20 (https://ftp.ssec.wisc.edu/pub/eosdb/j01) . The image above, for example, shows NOAA-20 Day Night Band imagery that combines data from the direct broadcast sites at AOML and San Juan (temporary direct link to CIMSS Direct Broadcast ftp site is here). The derived Sea Surface Temperature field from that time (here), shows River Surface Temperatures in the Amazon River basin! The first day-time image on 22 March, below, shows Suomi NPP (click here to see the orbits) data from the San Juan Puerto Rico antenna only — far out in the central Atlantic Ocean. (Here’s ATMS data — channel 21 at 183.31 GHz — that includes a map to help you judge where the data are!)

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