Severe weather occurred over the Deep South on 31 March (see this blog post); NOAA’s Storm Prediction Center (SPC) showed a Moderate Risk of severe weather over a region centered on Alabama; the toggle above shows the Moderate Risk in combination with the Tornadic Probailities. Here are the storm reports for this event. The overlap between the risk area and severe weather is here (or here at the SPC website); the overlap between the risk area and observed tornadoes is shown below (and here at the SPC website).

Observed tornadoes and SPC Risk from 1630 UTC on 30 March 2022 (Click to enlarge)

This blog post discussed output from Polar Hyperspetral modeling and how it could be used the day before. The animation below shows the Significant Tornado Potential parameter forecast at 2100 UTC on 30 March from initializations at 1200, 1400, 1700, 1800 and 2000 UTC (that is, 90, 7-, 4-, 3- and 1-hour forecasts). The areal extent of the maximum STP values is decreasing with time. Storm Reports from 30 March suggest that tornadic activity after 2100 UTC was in Mississippi and Louisiana. In addition, the largest values of STP did not extend to the into the northern part of the Moderate Risk.

In addition to being in the local AWIPS at CIMSS, in preparation for the Hazardous Weather Testbed, model output is also available at this link. The 00-h through 08-h forecast Lifted Index and Significant Tornado Parameter for this event, initialized at 2100 UTC, are shown below. The forecast shows that although the thermodynamic forcing might be dropping — as measured by the Lifted Index — the low-level wind field is becoming more favorable, as measured by the increase of STP as the system moves into Alabama.

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Which polar orbiters provide data to this modeling effort? Both Metop-B and Metop-C, as well as Suomi-NPP and NOAA-20. A 2100 UTC model initialization will include data from the afternoon passes of Suomi-NPP and NOAA-20 (it generally takes at most an hour for the polar orbiting data to be incorporated into the Data Fusion initializations). You can view orbital paths from the Metop satellites, and from JPSS, at this website.

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As part of the Hazardous Weather Testbed this year at the Storm Prediction Center, CIMSS will be demonstrating forecast model output initialized with hyperspectral data from Polar Orbiters that is fused with ABI data; this methodology takes advantage of (for example) the high spectral resolution of CrIS on NOAA-20 and the high spatial and temporal resolution of the ABI on GOES-16. (See this blog post). Preliminary storm reports for 29-30 March 2022 are shown above, scattered severe weather occurred over the southern Plains. What did the PHSnMWnABI data look like for this event, specifically for the severe weather in northwestern Arkansas reported around 0909 UTC?

The toggle above compares two estimates of instability, one using just thermodynamics (Convective Available Potential Energy — CAPE), one incorporating model wind fields as well (STP). This 11-hour forecast was a bit fast, bringing the largest tornado threat into northwestern Arkansas by 0700 UTC (in reality, per the SPC, severe weather occurred shortly after 0900 UTC). The toggle below compares 11-h forecast of CAPE to the initial field (i.e., 00-h) of CAPE at 0700 UTC and the GOES-16 Band 13 infrared (10.3 µm) satellite imagery at 0700 UTC. The initial field certainly shows enhanced instability lagging behind the coldest cloud tops!

ProbSevere (version 3), as shown at this website, will also be demonstrated at HWT this year. The readout below, from 0701 UTC, shows the strongest convection lagging the predicted region of strongest instability.

ProbSevere version 3 at 0916 UTC shows a maximum over the severe storm near Springdale, AR. The ProbSevere readout (from this website) for that radar object, shows a maximum value at 0910 UTC.

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Use the model forecast fields to better identify the regions of risk in the 3-12 hour timeframe, and then use observation-based products to hone in on exactly where the biggest threat exists.

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GOES-16 (GOES-East) Dust RGB images (above) highlighted the development of widespread blowing dust (brighter shades of pink/magenta) across northern Chihuahua, Mexico and parts of Texas, New Mexico and Oklahoma on 29 March 2022. Strong winds within the corridor between a dryline and an approaching cold front were gusting as high as 65 knots — and the lofted blowing dust was reducing the surface visibility to 1.5 miles at some locations. Much of that region had been experiencing severe to exceptional drought conditions.

GOES-16 True Color RGB images created using Geo2Grid (below) provided another view of the blowing dust plumes (shades of tan to light brown), as well as a few narrow plumes of smoke (dull shades of white) from wildfires that spread quickly due to the strong winds.

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Farther to the north, severe thunderstorms developed ahead of the dryline across eastern Kansas — and overlapping 1-minute GOES-16 Mesoscale Sectors provided 30-second imagery of these storms; “Red” Visible (0.64 µm) images with plots of time-matched SPC Storm Reports are shown above, during the hours leading up to sunset.

After sunset, isolated tornadoes were reported in northeastern Kansas and northwestern Missouri, as seen in GOES-16 “Clean” Infrared (10.35 µm) images (below).

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A 50- to 60-vehicle crash over central Schuylkill County (in Pennsylvania), with fatalities, on north-bound Interstate 81 occurred at around 11 AM EDT (TV news report; radio report), which is 1500 UTC. Day Cloud Phase Distinction, above shows the characteristic yellow/green/chartreuse shading that is associated with snow in cold air moving over I-81 in central Schuylkill County just before the reported time of the crashes. A longer animation below (with sparse surface observations — note no observations in Schuylkill County) during the day shows ongoing snow squalls during the course of the day.

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