{"id":14923,"date":"2021-07-13T09:32:29","date_gmt":"2021-07-13T15:32:29","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=14923"},"modified":"2021-07-14T09:22:06","modified_gmt":"2021-07-14T15:22:06","slug":"ftb-07-13-2021-showers-and-storms-return-for-many-flood-threat-limited-to-southern-high-terrain","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=14923","title":{"rendered":"FTB 07-13-2021: Showers and Storms Return For Many; Flood Threat Limited To Southern High Terrain"},"content":{"rendered":"<p>Issue Date: Tuesday, July 13th, 2021<br>\nIssue Time: 9:30AM MDT<\/p>\n<p><em>&mdash; A <strong>LOW<\/strong> flood threat has been posted for parts of the San Juan Mountains and Southeast Mountains<\/em><\/p>\n<p>As expected, changes are in the air over Colorado today. As shown in the visible satellite image, below, one easily seen difference since yesterday morning is the expansive deck of mid-level clouds seen mainly across northern and central Colorado. These clouds were mainly located in a narrow layer roughly 15-18k feet above the surface, as seen in both the Denver and Grand Junction soundings. They are associated with multiple disturbances, of <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;monsoon&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;a seasonal wind that brings moisture and rain to the region into which it blows; there is also a dry phase to monsoons, but popular usage refers only to the wet phase; these winds occur in many places around the world, and where they occur they are responsible for a majority of that location&rsquo;s annual precipitation&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>monsoon<\/span> origin, that have raised <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;precipitable water&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;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\"}]'>Precipitable Water<\/span> to about 0.8 inches at both Grand Junction and Denver. For most areas (as mentioned in yesterday&rsquo;s Outlook) it will take time to moisten the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;boundary layer&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;&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&amp;lt;br \/&amp;gt;&amp;lt;p&amp;gt;&amp;lt;span style=&amp;quot;color: #ffffff;&amp;quot;&amp;gt;The lower portion of the atmosphere that is directly influenced by the earth&amp;#039;s surface. Primarily, the boundary layer is driven by solar heating during the day and radiational cooling at night.&amp;lt;\/span&amp;gt;&amp;lt;\/p&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>boundary layer<\/span> to make it conducive for heavy rainfall. Additionally, the cloud deck will significantly impede instability for most of the state leading to a light to moderate intensity rainfall this afternoon and evening, so no complaints there.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_markup-2.png\"><img loading=\"lazy\" class=\" wp-image-14924 aligncenter\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_markup-2.png\" alt=\"\" width=\"690\" height=\"571\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_markup-2.png 738w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_markup-2-300x248.png 300w\" sizes=\"(max-width: 690px) 100vw, 690px\"\/><\/a><\/p>\n<p>There are two areas that we are watching for heavy rainfall chances. The first will be the climatologically favored San Juan Mountains and Southeast Mountains, where instability will locally exceed 1,000 J\/kg this afternoon. Rain rates have been on the higher side of our model guidance the past two days and today&rsquo;s guidance has significantly increased compared to yesterday. Thus, a Low flood threat is warranted for these areas through early evening, before instability quick diminishes and precipitation transitions to a more gradual rainfall. The second area is in the Northeast Plains where a cool front\/<span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow boundary&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A surface boundary formed by the horizontal spreading of thunderstorm-cooled air. Outflow boundaries may intersect with each other or with other features (fronts, dry line, low-level jet) and initiate new convection. Brief strong winds are possible with outflow boundaries, and they can also persist for more than 24 hours.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>outflow boundary<\/span> has moved in from the northeast. To the north of the boundary, only limited instability is expected. To the south, higher instability will support the chance of strong-to-<span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;severe thunderstorms&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Thunderstorms that produce a tornado, winds of at least 58 mph (50 kts) and\/or hail at least 1&amp;quot; in diameter.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>severe thunderstorms<\/span> that will be capable of heavy rainfall and damaging winds. However, the limiting factor is strong SE steering winds aloft that will limit point rainfall. Thus, rainfall rates are expected to stay just below flood thresholds.<\/p>\n<p>Finally, the change to more westerly flow aloft will finally clear out the smoky skies a bit today, as will any rainfall.<\/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.<br><img loading=\"lazy\" class=\"aligncenter wp-image-14933\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210713_snap.png\" alt=\"\" width=\"880\" height=\"596\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210713_snap.png 1786w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210713_snap-300x203.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210713_snap-768x520.png 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210713_snap-1024x694.png 1024w\" sizes=\"(max-width: 880px) 100vw, 880px\"\/><\/p>\n<h3><strong>Zone-Specific Forecasts:<\/strong><\/h3>\n<h4><strong>Grand Valley, Northwest Slope, Southwest Slope, Central Mountains, San Luis Valley, San Juan Mountains, Southeast Mountains &amp; Northern Mountains, Front Range:<\/strong><\/h4>\n<p><span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;scattered&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;25-40% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>Scattered<\/span> to <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;numerous&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;40-60% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>numerous<\/span> showers and thunderstorms developing, with better coverage for elevations above 7,500 feet. Max 30-minute rainfall up to 0.8 inches and max 1-hour rainfall up to 1.2 inches in southern areas, where a Low flood threat has been posted for <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> <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;flash flooding&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;flash flooding can refer to usually dry areas becoming rapidly inundated with water, or rapid water level rises on streams, creeks, or rivers beyond flood stage; typically caused by heavy rainfall, but can also be caused by meltwater&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>flash flooding<\/span>, debris slides and mud flows. Further north, max 1-hour rainfall up to 0.7 inches is possible. Gusty winds could accompany the stronger storms, especially over northern areas.<\/p>\n<p>Primetime: 12PM to 9PM<\/p>\n<h4><strong>Raton Ridge, Northeast Plains, Palmer Ridge, Urban Corridor &amp; Southeast Plains: <\/strong><\/h4>\n<p>Partly to mostly cloudy early, then <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> to <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;scattered&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;25-40% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>scattered<\/span> showers and thunderstorms possible this afternoon. Max 1-hour rainfall up to 1.5 inches in the east and 0.8 inches for the foothills and adjacent areas. Damaging winds will be possible with the stronger storms over the Northeast Plains. However, flooding is NOT expected today.<\/p>\n<p>Primetime: 1PM to 10PM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Tuesday, July 13th, 2021 Issue Time: 9:30AM MDT &mdash; A LOW flood threat has been posted for parts of the San Juan Mountains and Southeast Mountains As expected, changes are in the air over Colorado today. As shown in the visible satellite image, below, one easily seen difference since yesterday morning is the [&hellip;]<\/p>","protected":false},"author":4,"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\/14923"}],"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\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=14923"}],"version-history":[{"count":3,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/14923\/revisions"}],"predecessor-version":[{"id":14934,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/14923\/revisions\/14934"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=14923"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=14923"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=14923"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}