{"id":14948,"date":"2021-07-14T10:16:19","date_gmt":"2021-07-14T16:16:19","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=14948"},"modified":"2021-07-15T07:32:01","modified_gmt":"2021-07-15T13:32:01","slug":"ftb-07-14-2021-above-average-moisture-incoming-cold-front-enhance-flood-threat-2","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=14948","title":{"rendered":"FTB 07-14-2021: Above Average Moisture &#038; Incoming Cold Front Enhance Flood Threat"},"content":{"rendered":"<p>Issue Date: Wednesday, July 14th, 2021<br>\nIssue Time: 10:15AM MDT<\/p>\n<p><em>&mdash; <\/em><em>A&nbsp;<\/em><strong><em>MODERATE<\/em><\/strong><strong><em>&nbsp;<\/em><\/strong><em>flood threat has been issued for the Urban Corridor, San Juan Mountains and portions of the Front Range and Palmer Ridge<\/em><br><em>&mdash; <\/em><em>A&nbsp;<\/em><strong><em>LOW<\/em><\/strong><strong><em>&nbsp;<\/em><\/strong><em>flood threat has been issued for the higher terrains of the Northern Mountains, Northwest Slope, Grand Valley, Southwest Slope and Southeast Mountains. This threat also includes the Raton Ridge, Northeast Plains and Southeast Plains.<\/em><\/p>\n<p>The visible satellite imagery below shows the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;shortwave&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A disturbance in the mid or upper part of the atmosphere which induces upward motion ahead of it.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>shortwave<\/span> from yesterday to our north (orange &ldquo;X&rdquo;), which will continue to move to the east throughout today. An associated northerly surge of surface winds has started to move south over the eastern plains this morning, which is expected to increase surface moisture behind it. In addition, a surface Low over the plains today will help to reinforce surface moisture over this area on its east and north sides. Due to the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;shortwave&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A disturbance in the mid or upper part of the atmosphere which induces upward motion ahead of it.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>shortwave<\/span>&rsquo;s passage, the 500mb High has been pushed south and west, which has allowed for a nice plume of moisture to move northward. Currently over western Colorado, an upper-level disturbance is combining with the moisture plume to produce showers over the southwest corner of the state. Throughout the day, this upper Low is forecast to move eastward and produce extra lift out in front of it. All in all, plenty of moisture and lift over the state for&nbsp;<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> rainfall.<\/p>\n<p><img loading=\"lazy\" class=\"aligncenter wp-image-14941\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_20210714.jpg\" alt=\"\" width=\"775\" height=\"453\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_20210714.jpg 1672w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_20210714-300x175.jpg 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_20210714-768x449.jpg 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_20210714-1024x599.jpg 1024w\" sizes=\"(max-width: 775px) 100vw, 775px\"\/><\/p>\n<p>Moisture has already increased quite a bit over western Colorado, and <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 was measured at 1.11 inches. Over Denver, <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> remains around 0.80 inches, but is expected to increase to over an inch by later this afternoon. This well above average moisture will set the stage for heavy rainfall producing storms today, so a Moderate\/Low flood threat has been issued. As far as the evolution of rainfall development, the ongoing storms over southwest Colorado are expected to increase in intensity with a little daytime heating and spread into the Central Mountains. <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 will likely produce some higher totals over the southern San Juan Mountains, so a Moderate flood threat has been issued. The eastward movement of the upper-level disturbance will also help to produce <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> storms over the Southeast Mountains by early afternoon. Activity is anticipated to spill into the adjacent plains, and overnight rainfall is forecast for the Southeast Plains. Best chance for heavy rainfall over the plains will occur later this evening along the aforementioned SW to NE oriented boundary from this morning.<\/p>\n<p>In addition to the storms south, <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> storms are expected to develop over the Front Range with post-frontal upslope flow. Decent <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;CAPE&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;(Stands for: Convective Available Potential Energy) CAPE is a measure of the amount of available energy in the atmosphere for convection. Higher values indicate a greater potential for stronger updrafts, thus an increase in the potential for thunderstorms and severe weather.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>CAPE<\/span> is also forecast due to slightly better daytime heating. This means that some stronger thunderstorms may develop as the storms move off the mountains with the northwesterly steering flows. In addition to some hail and 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, high surface moisture will allow storms to produce very high rainfall rates. So, a Moderate flood threat has been issued for road, small stream\/creek and low-lying area flooding issues over the Urban Corridor and foothills.<\/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=\"wp-image-14951 aligncenter\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210714_snap.png\" alt=\"\" width=\"880\" height=\"593\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210714_snap.png 1788w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210714_snap-300x202.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210714_snap-768x517.png 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210714_snap-1024x690.png 1024w\" sizes=\"(max-width: 880px) 100vw, 880px\"\/><br><strong>Zone-Specific Forecasts:<\/strong><\/p>\n<h4><strong>Northern Mountains, Grand Valley, Northwest Slope, Southwest Slope, Central Mountains, San Luis Valley &amp; San Juan Mountains:<\/strong><\/h4>\n<p>Storms are anticipated to pick up in intensity and coverage by early afternoon. Best coverage of storms is anticipated over the Central and San Juan Mountains. Max 1-hour rain rates up to 1 inch will be possible with storm totals up to 1.5 inches. A Moderate flood threat has been issued. Further north, better instability may develop, which would allow for some thunderstorm activity later this afternoon. Storm movement will be more northerly during this period as the ridge builds to the west. Max 1-hour rain rates up to 1 inch will be possible with these storms, so a Low flood threat has been issued. Threats today over the steeper terrains include mud flows and debris slides as well as local stream\/creek flooding and road flooding.<\/p>\n<p>Primetime: 12PM to 12AM<\/p>\n<h4><strong>Front Range, Southeast Mountains, Palmer Ridge, Raton Ridge &amp; Urban Corridor:<\/strong><\/h4>\n<p><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> storms are anticipated to develop over the eastern high terrains this afternoon. Max 1-hour rain rates up to 1.25 inches (north) and 1 inch (south) are possible. This could cause mud flows and debris slides as well as road flooding over the steeper terrains. As storms move into the Urban Corridor, max 1-hour rain rates up to 2 inches will be possible, which could cause road, low-lying area and intersection flooding issues. A Moderate flood threat has been issued.<\/p>\n<p>Primetime: 1PM to 11PM<\/p>\n<h4><strong>Northeast Plains &amp; Southeast Plains:&nbsp; <\/strong><\/h4>\n<p>As storms move off the mountains and into the plains this afternoon, they will be moving into higher surface moisture. If the storms can make it into the plains before the instability drops off, max 1-hour rain rates up to 2 inches will be possible. Best chance for heavy rainfall will be along the left over cold front boundary that stalls out&nbsp;over the far eastern plains, which could make storms more stationary in nature. These storms may produce&nbsp;road flooding, field ponding and local stream flooding issues. Other threats from storms include hail and damaging <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. Storms will likely linger into the early morning hours over the Southeast Plains, but the flood threat should drop off around midnight. A Low flood threat has been issued.<\/p>\n<p>Primetime: 6PM to Midnight<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Wednesday, July 14th, 2021 Issue Time: 10:15AM MDT &mdash; A&nbsp;MODERATE&nbsp;flood threat has been issued for the Urban Corridor, San Juan Mountains and portions of the Front Range and Palmer Ridge &mdash; A&nbsp;LOW&nbsp;flood threat has been issued for the higher terrains of the Northern Mountains, Northwest Slope, Grand Valley, Southwest Slope and Southeast Mountains. [&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\/14948"}],"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=14948"}],"version-history":[{"count":3,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/14948\/revisions"}],"predecessor-version":[{"id":14953,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/14948\/revisions\/14953"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=14948"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=14948"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=14948"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}