{"id":327,"date":"2026-05-05T15:13:34","date_gmt":"2026-05-05T20:13:34","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/probsevere\/?p=327"},"modified":"2026-05-05T15:13:34","modified_gmt":"2026-05-05T20:13:34","slug":"a-hail-wind-day-in-early-may","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/probsevere\/2026\/05\/05\/a-hail-wind-day-in-early-may\/","title":{"rendered":"A hail\/wind day in early May"},"content":{"rendered":"\n

May the 4th was pretty much a mild-mannered hail\/wind risk day for early May. Nevertheless, there were some interesting cases from ProbSevere v4. Below are how the SPC outlooks verified for hail and wind.<\/p>\n\n\n\n

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First, near Detroit, Michigan, there was a small broken line segment of cells in a bowing pattern. PSv4 had very high probabilities (> 75%) out ahead of it, almost 30 minutes before a NWS severe thunderstorm warning and 35 minutes before the first severe wind report, which were all downstream from the bullseye, but still in the > 50% contour. The shape of the congealed cells surely played a role to increased probabilities here. The reports in the figures below are all of the reports in the next 45 minutes (i.e., the target field for PSv4).<\/p>\n\n\n\n

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Much later in eastern Kansas, there were a trio of severe wind reports near Emporia. This was the middle of the night, and ProbSevere v3 (object-based guidance) never got over 27%, with MESH of 0.7″, flash rate of 10\/min, and moderate mid- and low-level azimuthal shear. Correspondingly, PSv4 had a > 25% contour. Thus, this was a more uncertain case, might have been able to help forecasters issue a SVR warning to cover\/capture some of these reports. <\/p>\n\n\n\n

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Just a little later, in northeast Oklahoma, there was a fairly intense bowing segment plunging southeastward. PSv4 had > 75% probability much out ahead of the line, with over 1″ of MESH, 50 fl\/min, and strong low-level azimuthal shear. However, no warnings were issued and no severe reports were recorded. Thus, no AI model is perfect. This was an over-prediction by PSv4, and human forecasters got it right.<\/p>\n\n\n\n

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May the 4th was pretty much a mild-mannered hail\/wind risk day for early May. Nevertheless, there were some interesting cases from ProbSevere v4. Below are how the SPC outlooks verified for hail and wind. First, near Detroit, Michigan, there was a small broken line segment of cells in a bowing pattern. PSv4 had very high […]<\/p>\n","protected":false},"author":14,"featured_media":330,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[5],"tags":[],"class_list":["post-327","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-psv4"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/probsevere\/wp-json\/wp\/v2\/posts\/327","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cimss.ssec.wisc.edu\/probsevere\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cimss.ssec.wisc.edu\/probsevere\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/probsevere\/wp-json\/wp\/v2\/users\/14"}],"replies":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/probsevere\/wp-json\/wp\/v2\/comments?post=327"}],"version-history":[{"count":1,"href":"https:\/\/cimss.ssec.wisc.edu\/probsevere\/wp-json\/wp\/v2\/posts\/327\/revisions"}],"predecessor-version":[{"id":333,"href":"https:\/\/cimss.ssec.wisc.edu\/probsevere\/wp-json\/wp\/v2\/posts\/327\/revisions\/333"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/probsevere\/wp-json\/wp\/v2\/media\/330"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/probsevere\/wp-json\/wp\/v2\/media?parent=327"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/probsevere\/wp-json\/wp\/v2\/categories?post=327"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/probsevere\/wp-json\/wp\/v2\/tags?post=327"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}