{"id":5370,"date":"2026-07-20T11:53:10","date_gmt":"2026-07-20T11:53:10","guid":{"rendered":"https:\/\/ialert.com\/blog\/?p=5370"},"modified":"2026-07-20T11:53:10","modified_gmt":"2026-07-20T11:53:10","slug":"upper-midwest-severe-thunderstorms-july-20","status":"publish","type":"post","link":"https:\/\/ialert.com\/blog\/news-events\/upper-midwest-severe-thunderstorms-july-20\/","title":{"rendered":"Upper Midwest Severe Thunderstorms: Enhanced Risk July 20, 2026"},"content":{"rendered":"<p>   <iframe src=\"https:\/\/ialert.com\/blog_outlook.php?event=upper-midwest-severe-thunderstorms-july-20\" title=\"Upper Midwest\n  Severe Thunderstorms: Enhanced Risk July 20, 2026\" loading=\"lazy\" style=\"width:100%;border:0;\" height=\"660\"><\/iframe><\/p>\n<p>Upper Midwest severe thunderstorms are threatening Minnesota, Wisconsin, Iowa, Upper Michigan, and the broader Great<br \/>\n  Lakes region today, July 20, 2026, with the NOAA Storm Prediction Center placing the area under an Enhanced Risk, the<br \/>\n  third of five severe categories (level 3 of 5). SPC uses a five-tier system to communicate severe weather potential;<br \/>\n  you can <a href=\"https:\/\/ialert.com\/blog\/weather-articles\/severe-weather-outlook\/\">learn how each risk tier is<br \/>\n  defined<\/a> at iAlert. Swaths of damaging winds, large hail, and isolated tornadoes are all in play, particularly late<br \/>\n  this afternoon and into tonight.<\/p>\n<p><strong>Key points:<\/strong><\/p>\n<ul>\n<li>Enhanced Risk (level 3 of 5) centered on the Upper Midwest and Great Lakes for July 20, 2026.<\/li>\n<li>Main hazards: damaging winds (30% probability), large hail (15%), and a few tornadoes (5%).<\/li>\n<li>Peak timing: late afternoon through tonight, along a cold front pushing toward Wisconsin, Upper Michigan, and<br \/>\n  northern Iowa.<\/li>\n<li>A Slight Risk (level 2 of 5) also covers North Carolina and far southern Virginia for isolated damaging wind<br \/>\n  gusts.<\/li>\n<li>Early morning storms may precede a regional break, with more vigorous development expected by late<br \/>\n  afternoon.<\/li>\n<\/ul>\n<h2>What the SPC Is Forecasting<\/h2>\n<p>The SPC outlook identifies the Upper Midwest and Great Lakes vicinity as the day&#8217;s primary severe weather target.<br \/>\n  The agency puts the probability of damaging wind gusts at 30 percent, large hail at 15 percent, and tornadoes at 5<br \/>\n  percent within the Enhanced Risk area. Those numbers reflect meaningful coverage across a broad swath of the region,<br \/>\n  and the strongest Upper Midwest severe thunderstorms are most likely where all three hazards overlap across Wisconsin<br \/>\n  and northern Iowa.<\/p>\n<p>The outlook also draws a hatched area for significant severe wind inside the 30 percent zone, where the most intense<br \/>\n  storms could produce gusts on the order of 70 mph. Winds of that magnitude down trees and power lines and cause<br \/>\n  structural damage, which is why the SPC separates them from ordinary thunderstorm gusts.<\/p>\n<p>A separate Slight Risk, the second of five severe categories (level 2 of 5), covers North Carolina and far southern<br \/>\n  Virginia, where isolated damaging wind gusts are the main concern. This area carries lower overall severe potential but<br \/>\n  still warrants attention for residents from the Carolina Piedmont into the southern Virginia border zone.<\/p>\n<p>The SPC notes that early-morning convection across east and southeast Minnesota, western Wisconsin, and eastern Iowa<br \/>\n  could produce hail and strong wind gusts before tending to weaken during the day. The more dangerous round is expected<br \/>\n  to fire along the cold front by late afternoon, targeting Wisconsin, Upper Michigan, and northern and eastern Iowa.<br \/>\n  Check <a href=\"https:\/\/ialert.com\/analysis.php#alerts\">active weather alerts<\/a> throughout the day as conditions<br \/>\n  evolve.<\/p>\n<figure style=\"max-width:100%;margin:18px auto;padding:8px;border:1px solid #ddd;border-radius:4px;background:#fff;\">\n    <img loading=\"lazy\" decoding=\"async\" src=\"ttps:\/\/ialert.com\/blog\/wp-content\/uploads\/2026\/07\/ialert-upper-midwest-severe-thunderstorms-wind-risk-july-20-2026.jpg\" alt=\"Upper Midwest severe thunderstorms wind risk map for July 20, 2026, with a 30 percent damaging-wind \n  probability and a hatched significant-wind zone centered on Wisconsin and the Great Lakes.\" width=\"1600\" height=\"862\" \n  class=\"size-full wp-image-5375\" style=\"display:block;width:100%;max-width:100%;height:auto;border-radius:2px;\" srcset=\"https:\/\/ialert.com\/blog\/wp-content\/uploads\/2026\/07\/ialert-upper-midwest-severe-thunderstorms-wind-risk-july-20-2026.jpg 1600w, https:\/\/ialert.com\/blog\/wp-content\/uploads\/2026\/07\/ialert-upper-midwest-severe-thunderstorms-wind-risk-july-20-2026-300x162.jpg 300w, https:\/\/ialert.com\/blog\/wp-content\/uploads\/2026\/07\/ialert-upper-midwest-severe-thunderstorms-wind-risk-july-20-2026-1024x552.jpg 1024w, https:\/\/ialert.com\/blog\/wp-content\/uploads\/2026\/07\/ialert-upper-midwest-severe-thunderstorms-wind-risk-july-20-2026-1536x828.jpg 1536w\" sizes=\"auto, (max-width: 1600px) 100vw, 1600px\" \/><figcaption style=\"font-size:13px;color:#555;margin-top:8px;text-align:center;\">SPC damaging-wind probability for<br \/>\n  July 20, 2026. The hatched zone marks potential for significant gusts on the order of 70 mph. Source: NOAA Storm<br \/>\n  Prediction Center.<\/figcaption><\/figure>\n<h2>Meteorologist&#8217;s Take<\/h2>\n<p>The engine driving today&#8217;s Upper Midwest severe thunderstorms threat is a substantial shortwave trough currently<br \/>\n  sitting over southern Manitoba. That upper-level disturbance is amplifying and pushing southeast toward the Lake<br \/>\n  Superior region through tonight. As it does, a powerful stream of mid- and upper-level winds will accelerate across<br \/>\n  Minnesota and Wisconsin, with mid-level flow reaching 50 to 70 knots and upper-level winds topping 100 knots. That<br \/>\n  intense wind shear over a deep layer is what gives organized, long-lived storms their structure and punch.<\/p>\n<p>At the surface, the atmosphere is primed with rich moisture. Dewpoints are running in the upper 60s to the<br \/>\n  low-to-mid 70s Fahrenheit across the warm sector, and a plume of steep mid-level lapse rates, meaning temperatures fall<br \/>\n  sharply with altitude, is spreading into the region. That combination generates strong instability. Effective shear<br \/>\n  exceeding 50 knots favors discrete supercell storms capable of producing large hail and tornadoes, while any storm that<br \/>\n  consolidates into a line could produce widespread damaging wind gusts.<\/p>\n<p>The main forecast uncertainty involves early-morning convection and the cloud debris it may leave behind. If that<br \/>\n  debris suppresses afternoon heating, the evening round may be somewhat limited. If the atmosphere clears and recovers,<br \/>\n  the late-afternoon and nighttime convection could be more widespread and intense. Either way, the SPC&#8217;s confidence in a<br \/>\n  significant severe weather event across the Upper Midwest severe thunderstorms zone is high enough to maintain the<br \/>\n  Enhanced Risk designation.<\/p>\n<h2>How to Stay Safe During Upper Midwest Severe Thunderstorms<\/h2>\n<p>The specific hazards from today&#8217;s Upper Midwest severe thunderstorms are damaging wind gusts, large hail, and<br \/>\n  tornadoes. For wind and hail, bring vehicles under cover if possible and move outdoor furniture and loose objects<br \/>\n  inside before storms arrive. Large hail can shatter windows and damage roofs quickly, so avoid sheltering in vehicles<br \/>\n  or near glass when storms are nearby.<\/p>\n<p>For tornado preparedness, identify your lowest interior room on the ground floor, away from windows, now rather than<br \/>\n  when a warning is issued. Because storms are expected to continue into tonight, a nighttime tornado is a real<br \/>\n  possibility in parts of Minnesota, Wisconsin, and Upper Michigan. Make sure your phone is charged and weather alerts<br \/>\n  are enabled. iAlert&#8217;s <a href=\"https:\/\/ialert.com\/forecast.php\">local weather forecast<\/a> and <a \n  href=\"https:\/\/ialert.com\/analysis.php?tab=radar\">live radar<\/a> can help you track storm timing for your specific<br \/>\n  location.<\/p>\n<p>Monitor conditions closely: the two-round nature of today&#8217;s event means a relative lull in midday activity could be<br \/>\n  mistaken for the all-clear. The evening round tied to the cold front may be the more dangerous of the two. Stay<br \/>\n  weather-aware through the overnight hours, especially across Wisconsin, Upper Michigan, and northern Iowa.<\/p>\n<p>As a broader reminder for anyone in the Carolinas or southern Virginia, keep an eye on local alerts today as well.<br \/>\n  The Slight Risk area there signals that isolated wind damage is possible, even if the headline threat remains focused<br \/>\n  on the Upper Midwest severe thunderstorms corridor to the north.<\/p>\n<p><strong>Sources:<\/strong><\/p>\n<ul>\n<li><a href=\"https:\/\/www.spc.noaa.gov\/products\/outlook\/day1otlk.html\" target=\"_blank\" rel=\"noopener\">NOAA Storm Prediction Center, Day 1 Convective<br \/>\n  Outlook, July 20, 2026<\/a><\/li>\n<\/ul>\n<div style=\"background: #000000; padding: 20px 24px; margin: 20px 0; border-radius: 4px;\">\n<p style=\"color: #ffffff; font-size: 16px; font-weight: bold; margin: 0 0 6px 0;\">Get Severe Weather Alerts for Your<br \/>\n  Location<\/p>\n<p style=\"color: rgba(255,255,255,0.9); margin: 0 0 14px 0;\">When any NWS watch, warning, or advisory is issued for<br \/>\n  your area, iAlert sends you an immediate notification by email, text message, or phone call, 24 hours a day, 7 days a<br \/>\n  week.<\/p>\n<p>  <a href=\"https:\/\/ialert.com\/services\/severe-weather-alerts.php\" style=\"background: #C41226; color: #ffffff; padding:\n  10px 22px; text-decoration: none; border-radius: 3px; font-weight: bold; display: inline-block;\">Sign Up for Severe<br \/>\n  Weather Alerts &rarr;<\/a>\n  <\/div>\n","protected":false},"excerpt":{"rendered":"<p>Upper Midwest severe thunderstorms carry an Enhanced Risk July 20, 2026. Damaging winds, large hail, and tornadoes possible from Minnesota to the Great Lakes.<span class=\"more\"> <a href=\"https:\/\/ialert.com\/blog\/news-events\/upper-midwest-severe-thunderstorms-july-20\/\">Read More&#8230;<\/a><\/span><\/p>\n","protected":false},"author":6,"featured_media":5374,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","rank_math_focus_keyword":"Upper Midwest severe thunderstorms","rank_math_title":"Upper Midwest Severe Thunderstorms: 70 mph Gusts Jul 20","rank_math_description":"Upper Midwest severe thunderstorms bring an Enhanced Risk July 20, 2026: 70 mph gusts, large hail, and a few tornadoes near the Great Lakes."},"categories":[719],"tags":[772],"class_list":["post-5370","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news-events","tag-spc-outlook"],"acf":[],"_links":{"self":[{"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/posts\/5370","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/comments?post=5370"}],"version-history":[{"count":7,"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/posts\/5370\/revisions"}],"predecessor-version":[{"id":5380,"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/posts\/5370\/revisions\/5380"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/media\/5374"}],"wp:attachment":[{"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/media?parent=5370"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/categories?post=5370"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/tags?post=5370"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}