{"id":15561,"date":"2021-08-16T09:37:27","date_gmt":"2021-08-16T15:37:27","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=15561"},"modified":"2021-08-17T08:41:21","modified_gmt":"2021-08-17T14:41:21","slug":"ftb-08-16-2021-flood-threat-continues-over-southwest-colorado","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=15561","title":{"rendered":"FTB 08-16-2021: Flood Threat Continues Over Southwest Colorado"},"content":{"rendered":"<p>Issue Date: Monday, August 16th, 2021<br>\nIssue Time: 9:35AM MDT<\/p>\n<p><em>&mdash; <\/em><em>A&nbsp;<\/em><strong><em>LOW<\/em><\/strong><em>&nbsp;flood threat has been issued for the Southwest Slope and San Juan Mountains<\/em><\/p>\n<p>Visible satellite imagery below shows the 500mb High further west this morning, and plenty of smoke out West from the ongoing fires (gray hue). Colorado remains under northerly flow over the western border, which is moving a disturbance south this morning (orange &ldquo;X&rdquo;). There is another disturbance over the far Southeast Plains, and both disturbances are creating cloud cover with some embedded rainfall. Today, an incoming, west coast <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;trough&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;An elongated area of relatively low atmospheric pressure; the opposite of a ridge.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>trough<\/span> will start to push the High first south then west. That will place Colorado under both northerly and variable upper-level flow. Mid-level lift is forecast to remain over the western portion of the state, which will help generate more <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;widespread&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;greater than 60% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>widespread<\/span> showers and thunderstorms over the high terrains, especially south.<\/p>\n<p>Drier and <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;stable&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;&amp;lt;!-- wp:paragraph {&amp;quot;textColor&amp;quot;:&amp;quot;white&amp;quot;} --&amp;gt;\n&amp;lt;p class=&amp;quot;has-white-color has-text-color&amp;quot;&amp;gt;the atmosphere is considered stable if it resists air attempting to rise; the opposite of unstable&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>stable<\/span> conditions east of the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;Continental Divide&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;&amp;lt;!-- wp:paragraph {&amp;quot;textColor&amp;quot;:&amp;quot;white&amp;quot;} --&amp;gt;\n&amp;lt;p class=&amp;quot;has-white-color has-text-color&amp;quot;&amp;gt;the dividing line that separates the watersheds of the western and eastern United States; rivers west of the divide empty into the Pacific Ocean, while rivers east of the divide empty into the Atlantic Ocean or Gulf of Mexico&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>Continental Divide<\/span> are expected keep the area mostly rain-free today, although storms will be likely once again along and near the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;Divide&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;&amp;lt;!-- wp:paragraph {&amp;quot;textColor&amp;quot;:&amp;quot;white&amp;quot;} --&amp;gt;\n&amp;lt;p class=&amp;quot;has-white-color has-text-color&amp;quot;&amp;gt;the dividing line that separates the watersheds of the western and eastern United States; rivers west of the divide empty into the Pacific Ocean, while rivers east of the divide empty into the Atlantic Ocean or Gulf of Mexico&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>Divide<\/span> and perhaps south over the southern Southeast Mountains. <span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;PW&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;(Stands for: Precipitable Water) The total atmospheric water vapor contained in a vertical column of the atmosphere. It is typically measured in inches, and anomalously (deviation from normal) high values of precipitable water generally correlate to heavy rainfall potential.&lt;\/div&gt;\"  data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>PW<\/span> at Grand Junction remains around the same as yesterday (0.79 inches), but with slower steering flows and some <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;training&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Continuous or repeated rainfall over the same region&nbsp;in a relatively short time span. Training thunderstorms can produce very high rainfall totals and cause flash flooding.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>training<\/span> storms forecast, local accumulations should get a boost. Morning cloud cover may limit the coverage of instability, but some pockets of greater instability should still be able to form with strong August heating. That should allow for some stronger thunderstorms to develop over the Southwest Slope and San Juan Mountains that will be capable of producing heavy rainfall in their storm cores. Increased runoff may also be an issue if storms track over the areas that have received rainfall the last couple of days. A LOW flood threat has been issued.<\/p>\n<p><img loading=\"lazy\" class=\"aligncenter wp-image-15562\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/vis_20210816.png\" alt=\"\" width=\"700\" height=\"472\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/vis_20210816.png 1224w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/vis_20210816-300x202.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/vis_20210816-768x518.png 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/vis_20210816-1024x691.png 1024w\" sizes=\"(max-width: 700px) 100vw, 700px\"\/><\/p>\n<h3><strong>Today&rsquo;s Flood Threat Map<\/strong><\/h3>\n<p>For more information on today&rsquo;s flood threat, see the map below. If there is a threat, hover over the threat areas for more details, and click on burn areas to learn more about them. For Zone-Specific forecasts, scroll below the threat map.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/FTB_20210816_snap.jpeg\"><img loading=\"lazy\" class=\" wp-image-15581 aligncenter\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/FTB_20210816_snap-1024x688.jpeg\" alt=\"\" width=\"889\" height=\"597\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/FTB_20210816_snap-1024x688.jpeg 1024w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/FTB_20210816_snap-300x201.jpeg 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/FTB_20210816_snap-768x516.jpeg 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/FTB_20210816_snap.jpeg 1790w\" sizes=\"(max-width: 889px) 100vw, 889px\"\/><\/a><\/p>\n<h3><strong>Zone-Specific Forecasts:<\/strong><\/h3>\n<h4><strong>Grand Valley, Central Mountains, San Luis Valley, San Juan Mountains, Northwest Slope, Northern Mountains, &amp; Southwest Slope:<\/strong><\/h4>\n<p>Max 1-hour rain rates up to 1.25 inches with storm totals up to 1.75 inches will be possible over the San Juan Mountains and Southwest Slope this afternoon where stronger instability can develop. Cloud cover is already starting to break-up, which indicates more instability may be able to build. This could lead to <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;isolated&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;less than 10% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>isolated<\/span> road flooding, mud flows\/debris slides and local stream flooding, especially if storms track over the same areas as the last couple of days. Additional threats include strong <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A cool pool of air that results when a thunderstorm downdraft reaches the surface and spreads horizontally.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>outflow<\/span> winds and perhaps some hail. A LOW flood threat has been issued. Storms to the north should be anchored to the high terrains with the weak northerly steering flow. Max 1-hour rain rates up to 0.50 inches will be possible with more storms producing totals around 0.25 inches. Lower elevations should stay dry.<br>\nPrimetime: 12:30PM to 10PM<\/p>\n<h4><strong>Northeast Plains, Urban Corridor, Raton Ridge, Palmer Ridge, Southeast Plains, Southeast Mountains &amp; Front Range:<\/strong><\/h4>\n<p>More <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;stable&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;&amp;lt;!-- wp:paragraph {&amp;quot;textColor&amp;quot;:&amp;quot;white&amp;quot;} --&amp;gt;\n&amp;lt;p class=&amp;quot;has-white-color has-text-color&amp;quot;&amp;gt;the atmosphere is considered stable if it resists air attempting to rise; the opposite of unstable&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>stable<\/span> conditions are forecast across&nbsp;the lower elevations this afternoon, which should keep rainfall confined to areas along and near the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;Continental Divide&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;&amp;lt;!-- wp:paragraph {&amp;quot;textColor&amp;quot;:&amp;quot;white&amp;quot;} --&amp;gt;\n&amp;lt;p class=&amp;quot;has-white-color has-text-color&amp;quot;&amp;gt;the dividing line that separates the watersheds of the western and eastern United States; rivers west of the divide empty into the Pacific Ocean, while rivers east of the divide empty into the Atlantic Ocean or Gulf of Mexico&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>Continental Divide<\/span>. There could also be a couple storms that form over the southern Southeast Mountains. <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;isolated&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;less than 10% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>Isolated<\/span> max 1-hour rain rates up to 0.75 inches will be possible (central\/south) with storms that develop over the Northern Front Range producing totals closer to 0.30 inches. Over the far Southeast Plains, if storms can overcome the <span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;cap&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The area where a parcel of air has negative buoyancy or sinks. The intensity of the cap is measured by its convective inhibition. If the cap is sufficiently large, it may prevent thunderstorms from forming at all.&lt;\/div&gt;\"  data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>cap<\/span> along a <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;dryline&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A low-level, small-scale boundary that separates dry air from moist air. Storms develop along it because the dry air (behind the boundary) is less dense than the moisture-rich air (ahead of the boundary). Typically, it advances eastward during the afternoon and retreats westward at night.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>dryline<\/span>, 1-hour rain rates up to 1.25 inches will be possible. First, we&rsquo;ll need the cloud cover to clear out and mid-level energy to move through the area during peak heating. We&rsquo;ve got the first ingredient already occurring. Flooding is NOT forecast for these regions today.<br>\nPrimetime: 1PM to 8PM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Monday, August 16th, 2021 Issue Time: 9:35AM MDT &mdash; A&nbsp;LOW&nbsp;flood threat has been issued for the Southwest Slope and San Juan Mountains Visible satellite imagery below shows the 500mb High further west this morning, and plenty of smoke out West from the ongoing fires (gray hue). Colorado remains under northerly flow over the [&hellip;]<\/p>","protected":false},"author":8,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[6],"tags":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/15561"}],"collection":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=15561"}],"version-history":[{"count":5,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/15561\/revisions"}],"predecessor-version":[{"id":15582,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/15561\/revisions\/15582"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15561"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15561"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15561"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}