{"id":5549,"date":"2026-08-14T16:33:07","date_gmt":"2026-08-14T16:33:07","guid":{"rendered":"https:\/\/ialert.com\/blog\/?p=5549"},"modified":"2026-08-14T16:33:07","modified_gmt":"2026-08-14T16:33:07","slug":"missouri-valley-severe-thunderstorms-2","status":"publish","type":"post","link":"https:\/\/ialert.com\/blog\/news-events\/missouri-valley-severe-thunderstorms-2\/","title":{"rendered":"Missouri Valley Severe Thunderstorms: Slight Risk of Damaging Wind and Tornado Threat August 14, 2026"},"content":{"rendered":"<p> <iframe src=\"https:\/\/ialert.com\/blog_outlook.php?event=missouri-valley-severe-thunderstorms\" title=\"Missouri Valley Severe \n  Thunderstorms: Slight Risk of Damaging Wind and Tornado Threat August 14, 2026\" loading=\"lazy\" style=\"width:100%;border:0;\" \n  height=\"660\"><\/iframe><\/p>\n<p><strong>Missouri Valley severe thunderstorms<\/strong> are the headline concern in the NOAA Storm Prediction Center&#8217;s Day 1<br \/>\n  Convective Outlook issued at 12:47 UTC on August 14, 2026, with a Slight Risk covering a corridor from Omaha, Nebraska, through Des<br \/>\n  Moines and Cedar Rapids, Iowa, and into Peoria and Bloomington, Illinois. Forecasters Mosier and Dean write that strong to severe<br \/>\n  thunderstorms will be possible this afternoon and evening across the mid Missouri and mid Mississippi Valleys, with damaging wind gusts<br \/>\n  as the primary hazard and a brief tornado also possible.<\/p>\n<p><strong>Key points:<\/strong><\/p>\n<ul>\n<li>A Slight Risk (level 2 of 5) for Missouri Valley severe thunderstorms centered on Omaha, Des Moines, Cedar Rapids, the Quad<br \/>\n  Cities, and Peoria.<\/li>\n<li>The 15% damaging wind area covers 56,970 square miles and 3,664,888 people, and it matches the Slight Risk outline exactly.<\/li>\n<li>A 2% tornado probability spans 30,047 square miles from Des Moines east to Moline, Illinois.<\/li>\n<li>A 5% large hail probability applies separately to the Denver area and to the Omaha to Des Moines corridor.<\/li>\n<li>A Marginal Risk runs from Denver and Kansas City through Chicago and Indianapolis to the Virginia coast, plus a separate area<br \/>\n  over southern Nevada.<\/li>\n<\/ul>\n<div style=\"background:#000000; padding:22px 24px; margin:24px 0; border-radius:4px;\">\n<p style=\"color:#ffffff; font-size:18px; font-weight:bold; margin:0 0 6px 0;\">Get iAlert Notifications for Your Location<\/p>\n<p style=\"color:rgba(255,255,255,0.9); margin:0 0 16px 0;\">The moment a threat is issued for your area, iAlert sends an immediate alert by email, text message, or phone call, 24\/7. Choose the alerts you need:<\/p>\n<p><a href=\"https:\/\/ialert.com\/services\/severe-weather-alerts.php\" style=\"background:#C41226; color:#ffffff; padding:11px 22px; text-decoration:none; border-radius:3px; font-weight:bold; display:inline-block; margin:0 12px 8px 0;\">Severe Weather Alerts &rarr;<\/a><br \/>\n<a href=\"https:\/\/ialert.com\/services\/lightning_detection_alerts.php\" style=\"background:#C41226; color:#ffffff; padding:11px 22px; text-decoration:none; border-radius:3px; font-weight:bold; display:inline-block; margin:0 0 8px 0;\">&#9889; Lightning Detection Alerts &rarr;<\/a>\n<\/div>\n<h2>Where Missouri Valley Severe Thunderstorms Are Most Likely Today<\/h2>\n<p>The Slight Risk is the second of five categories on the SPC scale; for the full breakdown see the <a \n  href=\"https:\/\/ialert.com\/blog\/weather-articles\/severe-weather-outlook\/\">iAlert guide to SPC outlook risk categories<\/a>. Today it<br \/>\n  covers Omaha NE, Council Bluffs IA, Des Moines IA, West Des Moines IA, Ames IA, Cedar Rapids IA, Iowa City IA, Davenport IA, Moline IL,<br \/>\n  Ottumwa IA, Burlington IA, Peoria IL, Bloomington IL, and Galesburg IL.<\/p>\n<p>One detail is worth pulling out of the maps. The 15% damaging wind polygon and the Slight Risk polygon are the same shape, so every<br \/>\n  city in the category carries the 15% wind probability and no city outside it does. Damaging wind by itself is what lifted this corridor<br \/>\n  to Slight, and SPC puts that area at 56,970 square miles covering 3,664,888 people.<\/p>\n<p>The 2% tornado probability sits entirely inside the <strong>Missouri Valley severe thunderstorms<\/strong> corridor but covers a<br \/>\n  narrower footprint, 30,047 square miles and 1,945,843 people. It takes in Des Moines, West Des Moines, Cedar Rapids, Iowa City,<br \/>\n  Davenport, Moline IL, Galesburg IL, Ottumwa, and Burlington. It does not reach Omaha, Council Bluffs, Peoria, or Bloomington.<\/p>\n<p>The hazard footprints diverge again on hail. Peoria, Bloomington, Davenport, Moline, and Galesburg sit inside the Slight Risk but<br \/>\n  carry no 5% large hail probability, while Omaha, Council Bluffs, Des Moines, Ames, Cedar Rapids, Iowa City, Ottumwa, and Burlington do.<br \/>\n  Anyone reading only the categorical map misses that split, which is why today&#8217;s <strong>Missouri Valley severe thunderstorms<\/strong><br \/>\n  need to be read hazard by hazard rather than by color alone.<\/p>\n<p>A second, disconnected 5% hail area covers the Colorado Front Range: Denver, Aurora, Colorado Springs, Pueblo, Limon CO, and<br \/>\n  Cheyenne WY. Those cities sit in the Marginal Risk categorically, yet they carry the same top hail probability as the Iowa and Nebraska<br \/>\n  corridor. Across both areas the 5% hail probability spans 85,889 square miles and 6,429,204 people.<\/p>\n<p>The Marginal Risk zone outside the <strong>Missouri Valley severe thunderstorms<\/strong> core is large, and a 5% damaging wind<br \/>\n  probability covers nearly all of it: 424,122 square miles and 48,228,215 people. It runs from Denver and Cheyenne east through Wichita<br \/>\n  KS, Topeka KS, Kansas City MO, Chicago IL, Rockford IL, Joliet IL, Champaign IL, Springfield IL, Gary IN, Lafayette IN, Indianapolis<br \/>\n  IN, Cincinnati OH, Louisville KY, and Charleston WV, then on to Roanoke VA, Richmond VA, Norfolk VA, Greensboro NC, and Raleigh NC. A<br \/>\n  separate Marginal area covers Las Vegas NV and the surrounding southern Nevada desert.<\/p>\n<figure class=\"wp-block-image size-full\" style=\"max-width:880px;margin:28px auto;padding:10px;border:1px solid \n  #dde3ec;border-radius:6px;background:#ffffff;\"><br \/>\n    <img decoding=\"async\" \n  src=\"https:\/\/ialert.com\/blog\/wp-content\/uploads\/2026\/08\/ialert-missouri-valley-severe-thunderstorms-wind-risk-august-14-2026.jpg\" \n  alt=\"Missouri Valley severe thunderstorms damaging wind probability map for August 14, 2026, showing the SPC 15% wind risk over Iowa \n  and eastern Nebraska inside a 5% wind risk stretching from Colorado and Kansas to Virginia and North Carolina\" width=\"1600\" \n  height=\"888\" style=\"max-width:100%;height:auto;border-radius:4px;\" loading=\"lazy\" \/><figcaption style=\"font-size:0.86em;color:#1a3a5c;text-align:center;margin:12px 6px 2px;line-height:1.45;\">SPC damaging wind<br \/>\n  probabilities for August 14, 2026. The 15% area (yellow) over Iowa and eastern Nebraska is the core of today&#8217;s Missouri Valley severe<br \/>\n  thunderstorms threat and matches the Slight Risk outline exactly. The surrounding 5% area (brown) reaches from Colorado and Kansas<br \/>\n  through Chicago and Indianapolis to Virginia and North Carolina. Source: NOAA Storm Prediction Center.<\/figcaption><\/figure>\n<h2>Meteorologist&#8217;s Take on Missouri Valley Severe Thunderstorms<\/h2>\n<p>The SPC&#8217;s reasoning for today&#8217;s <strong>Missouri Valley severe thunderstorms<\/strong> centers on a well-defined mesoscale convective<br \/>\n  vortex (MCV), the spinning remnant left behind by a dying cluster of storms, generated by overnight convection across Kansas and<br \/>\n  Nebraska. At issuance an extensive band of showers and thunderstorms ran from northeast Nebraska southeastward across central Iowa,<br \/>\n  central Illinois, and central Indiana, supported by warm-air advection along a broad, diffuse frontal zone from southeast Nebraska<br \/>\n  across northern Missouri and southern Illinois.<\/p>\n<p>That band should wane through the morning as the low-level jet driving the warm-air advection weakens. The afternoon phase of the<br \/>\n  <strong>Missouri Valley severe thunderstorms<\/strong> then turns on how much the air mass recovers along the southern edge of the band,<br \/>\n  ahead of the MCV, where ample low-level moisture is already in place.<\/p>\n<p>Differential heating between the residual cloud debris and the clearer air south of it could produce a warm-front-like zone across<br \/>\n  southern Iowa or northern Missouri. Where that boundary sets up, how strong it gets, and exactly where it lands all remain uncertain,<br \/>\n  largely because of the limited predictability of how the ongoing precipitation evolves. That single uncertainty is what makes today&#8217;s<br \/>\n  threat hard to pin to a specific county this far ahead.<\/p>\n<p>The air mass along and south of the boundary is forecast to destabilize and become moderately to strongly unstable by late<br \/>\n  afternoon. Low-level convergence there should be augmented by mesoscale ascent tied to the MCV, and that combination of lift and<br \/>\n  buoyancy will support storm development. A belt of stronger mid-level flow could accompany the MCV, delivering enough deep-layer shear<br \/>\n  to organize any persistent updrafts.<\/p>\n<p>Strong gusts from water-loaded downdrafts and from any bowing segments are the primary severe risk with these <strong>Missouri<br \/>\n  Valley severe thunderstorms<\/strong>. The boundary combined with southeasterly low-level flow also supports a brief tornado,<br \/>\n  particularly early in the convective cycle when a more cellular storm mode is likely.<\/p>\n<p>The Ohio Valley, central Appalachians, and Mid-Atlantic carry their own reasoning. Showers ongoing from Illinois into Ohio should<br \/>\n  weaken this morning, but the cloud cover they leave behind could reinforce a modest baroclinic zone from southern Illinois across<br \/>\n  southern Indiana and southern Ohio and through central West Virginia and central Virginia. A modest vorticity maximum over central<br \/>\n  Illinois is forecast to track southeast along and north of that boundary.<\/p>\n<p>Vertical shear in that eastern corridor will be weak, so organized storms are not the concern there. Strong updrafts feeding on<br \/>\n  ample moisture are, and the SPC flags a threat for wet microbursts: sudden, localized downbursts of rain-cooled air that hit the ground<br \/>\n  and spread out as damaging straight-line wind. That is the mechanism behind the 5% wind probability from Louisville and Cincinnati<br \/>\n  east to Richmond and Norfolk.<\/p>\n<p>Over the central High Plains, a shortwave trough moving through the lower Colorado River Valley will continue northeastward through<br \/>\n  the Four Corners. Ascent from that wave combines with orographic lift in the Rockies foothills to support scattered initiation by early<br \/>\n  afternoon, with storms then moving northeast into a moderately buoyant air mass. Deep-layer shear there is modest but sufficient for a<br \/>\n  few organized updrafts capable of hail and damaging gusts, which is what earns Denver and Colorado Springs their 5% hail<br \/>\n  probability.<\/p>\n<p>In southern Nevada, dewpoints in the 60s across southern California, the lower Colorado River Valley, and southern Arizona combine<br \/>\n  with strong daytime heating to produce moderate buoyancy. Slightly stronger mid-level flow over southern Nevada supports isolated<br \/>\n  strong gusts around Las Vegas.<\/p>\n<h2>How to Stay Safe During Missouri Valley Severe Thunderstorms<\/h2>\n<p>Because the primary hazard with today&#8217;s <strong>Missouri Valley severe thunderstorms<\/strong> is damaging wind, with a tornado<br \/>\n  threat across the Iowa and western Illinois portion, residents from Omaha and Des Moines through Cedar Rapids, the Quad Cities, and<br \/>\n  Peoria need a way to receive warnings before storms arrive. Sign up for <a href=\"https:\/\/ialert.com\/\">iAlert weather alerts and<br \/>\n  notifications<\/a> to get real-time severe weather warnings sent directly to you, and watch <a \n  href=\"https:\/\/ialert.com\/analysis.php?tab=radar\">live radar<\/a> as storms develop this afternoon and evening.<\/p>\n<p>If a tornado warning is issued, move immediately to the lowest floor of a sturdy building and put as many walls between you and the<br \/>\n  outside as possible. Stay away from windows. A 2% tornado probability is low in absolute terms, but lead time on a brief tornado near a<br \/>\n  surface boundary is short, so the plan has to exist before the watch is issued.<\/p>\n<p>For damaging wind, treat any severe thunderstorm warning with the same urgency during these <strong>Missouri Valley severe<br \/>\n  thunderstorms<\/strong>. Secure or bring in outdoor furniture and anything that could become a projectile, stay indoors and away from<br \/>\n  windows, and avoid parking under large trees. Wet microbursts in the Ohio Valley and Mid-Atlantic can produce damaging gusts with<br \/>\n  little visual warning beyond a heavy rain shaft.<\/p>\n<p>In the Denver and Colorado Springs area, where the 5% hail probability applies despite the lower categorical tier, vehicles parked<br \/>\n  outside are the main exposure. Move cars into a garage or covered parking before storms initiate in the early afternoon, several hours<br \/>\n  ahead of the evening peak farther east.<\/p>\n<h2>Missouri Valley Severe Thunderstorms FAQ<\/h2>\n<h3>Where is the highest risk for Missouri Valley severe thunderstorms today?<\/h3>\n<p>The Slight Risk is the highest tier drawn anywhere in today&#8217;s outlook. It covers Omaha NE, Council Bluffs IA, Des Moines IA, West<br \/>\n  Des Moines IA, Ames IA, Cedar Rapids IA, Iowa City IA, Davenport IA, Moline IL, Ottumwa IA, Burlington IA, Peoria IL, Bloomington IL,<br \/>\n  and Galesburg IL.<\/p>\n<h3>How strong could wind gusts get?<\/h3>\n<p>The SPC assigns a 15% damaging wind probability to the Missouri Valley severe thunderstorms corridor, meaning a 15% chance of a<br \/>\n  damaging wind report within 25 miles of any given point. The discussion names strong gusts from water-loaded downdrafts and bowing<br \/>\n  segments as the primary threat. The outlook does not specify an explicit gust speed.<\/p>\n<h3>Are tornadoes expected with today&#8217;s Missouri Valley severe thunderstorms?<\/h3>\n<p>The SPC places a 2% tornado probability over Des Moines, West Des Moines, Cedar Rapids, Iowa City, Davenport, Moline, Galesburg,<br \/>\n  Ottumwa, and Burlington. The discussion says a brief tornado is possible, particularly early in the convective cycle when a more<br \/>\n  cellular storm mode is likely near the surface boundary.<\/p>\n<h3>When will storms develop and move through the region?<\/h3>\n<p>The morning storm band is expected to weaken, with the main development tied to afternoon destabilization along a boundary across<br \/>\n  southern Iowa or northern Missouri. Missouri Valley severe thunderstorms should run through the afternoon and evening, and this outlook<br \/>\n  is valid until 7 a.m. CDT Saturday, August 15.<\/p>\n<p>  is valid until 7 a.m. CDT Saturday, August 15.<\/p>\n<h3>Why are Denver and Las Vegas in an outlook about Missouri Valley severe thunderstorms?<\/h3>\n<p>They sit in separate risk areas covered by the same national Day 1 outlook. Denver and Colorado Springs carry a 5% large hail<br \/>\n  probability from High Plains storms firing off the Rockies foothills, and southern Nevada carries a 5% wind probability from isolated<br \/>\n  strong gusts. Neither is connected to the Iowa corridor.<\/p>\n<p><strong>Sources:<\/strong><\/p>\n<ul>\n<li><a href=\"https:\/\/www.spc.noaa.gov\/products\/outlook\/archive\/2026\/day1otlk_20260814_1300.html\" target=\"_blank\" rel=\"noopener\">NOAA Storm Prediction Center, Day 1<br \/>\n  Convective Outlook, issued 12:47 UTC August 14, 2026 (SPC AC 141247, Mosier\/Dean)<\/a><\/li>\n<li><a href=\"https:\/\/www.spc.noaa.gov\/products\/outlook\/day1otlk.html\" target=\"_blank\" rel=\"noopener\">NOAA Storm Prediction Center, current Day 1 Convective<br \/>\n  Outlook<\/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 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 your area, iAlert<br \/>\n  sends you an immediate notification by email, text message, or phone call, 24 hours a day, 7 days a week.<\/p>\n<p>  <a href=\"https:\/\/ialert.com\/services\/severe-weather-alerts.php\" style=\"background: #C41226; color: #ffffff; padding: 10px 22px; \n  text-decoration: none; border-radius: 3px; font-weight: bold; display: inline-block;\">Sign Up for Severe Weather Alerts &rarr;<\/a>\n  <\/div>\n","protected":false},"excerpt":{"rendered":"<p>Missouri Valley severe thunderstorms carry a Slight Risk August 14, with a 15% damaging wind probability and tornado potential near Des Moines.<span class=\"more\"> <a href=\"https:\/\/ialert.com\/blog\/news-events\/missouri-valley-severe-thunderstorms-2\/\">Read More&#8230;<\/a><\/span><\/p>\n","protected":false},"author":6,"featured_media":5551,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","rank_math_focus_keyword":"missouri valley severe thunderstorms","rank_math_title":"Missouri Valley Severe Thunderstorms: 15% Wind Risk","rank_math_description":" Missouri Valley severe thunderstorms carry a Slight Risk Aug 14, with a 15% damaging wind probability and 2% tornado risk near Des Moines."},"categories":[719],"tags":[772],"class_list":["post-5549","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\/5549","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=5549"}],"version-history":[{"count":3,"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/posts\/5549\/revisions"}],"predecessor-version":[{"id":5554,"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/posts\/5549\/revisions\/5554"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/media\/5551"}],"wp:attachment":[{"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/media?parent=5549"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/categories?post=5549"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ialert.com\/blog\/wp-json\/wp\/v2\/tags?post=5549"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}