{"id":14709,"date":"2021-07-02T09:41:13","date_gmt":"2021-07-02T15:41:13","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=14709"},"modified":"2021-07-03T07:59:41","modified_gmt":"2021-07-03T13:59:41","slug":"ftb-07-02-2021-low-flood-threat-returns-for-eastern-mountains-and-adjacent-plains","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=14709","title":{"rendered":"FTB 07-02-2021: Low Flood Threat Returns for Eastern Mountains and Adjacent Plains"},"content":{"rendered":"<p>Issue Date: Friday, July 2nd, 2021<br>\nIssue Time: 9:40AM MDT<\/p>\n<p><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 Southeast Mountains, Raton Ridge and portions of the Front Range, Central Mountains, Urban Corridor and Palmer Ridge<\/em><\/p>\n<p>The visible satellite imagery below is showing pockets of fog and cloud cover across the eastern plains and in some of the mountain valleys this morning. It is 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> over the adjacent eastern plains with the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;dew points&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The temperature to which a given air parcel must be cooled (at constant pressure and water vapor content) in order for saturation to occur.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>dew points<\/span> in the upper 50Fs to low 60Fs range. The upper Low from yesterday is currently over northern Wyoming, and it will continue to pull northward throughout the day while the High and associated ridge begins to reestablish itself back over the southwest US.<\/p>\n<p>While moisture is about the same over western Colorado (<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 0.93 inches), it has dropped slightly over eastern Colorado (<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 0.87 inches). This is still quite elevated, and with lower-end steering flow forecast again under the building ridge, the <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> storms that develop (east) will again be capable of local heavy rainfall this afternoon and evening. Guidance is indicating that the westerly steering flows over eastern Colorado will be slightly higher in magnitude than yesterday. This in tandem&nbsp;with the more <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> nature of the rainfall today, will help to limit the heavy rainfall threat.<\/p>\n<p><img loading=\"lazy\" class=\"aligncenter wp-image-14710\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_20210702.jpg\" alt=\"\" width=\"700\" height=\"500\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_20210702.jpg 1512w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_20210702-300x214.jpg 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_20210702-768x549.jpg 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/vis_20210702-1024x731.jpg 1024w\" sizes=\"(max-width: 700px) 100vw, 700px\"\/><\/p>\n<p>There are also no noticeable shortwaves moving through the flow this afternoon, so this will support the heavy downpours to be more <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> in nature. As the west and northwest steering flow drive the storms into the adjacent eastern plains this afternoon, they are expected to have a better chance of producing higher rain rates further south. <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow boundaries&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 boundaries<\/span> may trigger some additional <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;convection&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Refers to vertical atmospheric motion driven by buoyancy, i.e., warm air is less dense than cool air, and therefore rises. One of the primary drivers of thunderstorm development, especially during monsoon season.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>convection<\/span> further east, so the Low has been extended due to the elevated moisture in the area.<\/p>\n<p>The mountains, particularly the southern Front Range\/northern Southeast Mountains have seen a lot of rainfall over the last 48-hours. Saturated soils and another round of heavy rainfall producing storms this afternoon will increase the runoff, debris flow and local stream flood threat. A Low flood threat has been issued for this reason. Over western Colorado, storm motion will be slightly faster, storm cores a bit smaller, and a larger spread in <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;dew point&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The temperature to which a given air parcel must be cooled (at constant pressure and water vapor content) in order for saturation to occur.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>dew point<\/span>\/temperature will cause rainfall rates to less efficient, so no flood threat has been issued.<\/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><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210702_snap.png\"><img loading=\"lazy\" class=\"aligncenter  wp-image-14728\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210702_snap.png\" alt=\"\" width=\"890\" height=\"605\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210702_snap.png 894w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210702_snap-300x204.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210702_snap-768x522.png 768w\" sizes=\"(max-width: 890px) 100vw, 890px\"\/><\/a><\/p>\n<h3><strong>Zone-Specific Forecasts:<\/strong><\/h3>\n<h4><strong>Front Range, Palmer Ridge, Southeast Mountains, Central Mountains, Raton Ridge &amp; Urban Corridor:<\/strong><\/h4>\n<p>Storms are expected to begin by midday again with more <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> coverage than <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> coverage (when&nbsp;compared to yesterday). Over the southern Front Range and Southeast Mountains, max 1-hour rain rates up to 1.10 inches will be possible. Over the northern Front Range and Central Mountains max 1-hour rain rates up to 0.75 inches will be possible. Over the adjacent plains, max 1-hr rain rates up to 1.50 inches (north) and 1.75 inches (south) will be possible. A Low Flood threat has been issued. Flood threats over the steeper terrains include excess runoff into local streams, mud flows and debris slides. Over the adjacent plains, road, local stream, and field ponding will be possible. The heavy rainfall threat is expected to end soon after sundown.<\/p>\n<p>Primetime: Noon to 10PM<\/p>\n<h4><strong>Northeast Plains &amp; Southeast Plains:&nbsp; <\/strong><\/h4>\n<p>No rainfall is anticipated for the&nbsp;far eastern plains today, but a couple <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow boundaries&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 boundaries<\/span> back to the west could trigger some storms over these regions late this afternoon and evening. Max 1-hour rain rates up to 1.75 inches would be possible with slightly higher storm totals further south. A Low flood threat has been issued for road, field and local stream flooding.<\/p>\n<p>Primetime: 4:30PM to 11PM<\/p>\n<h4><strong>Northern Mountains, San Luis Valley, San Juan Mountains, Grand Valley, Northwest Slope &amp; Southwest Slope:<\/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> storms will develop over the elevated plateaus and mountains this afternoon with best coverage anticipated closer 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>. Max 1-hour rain rates up to 0.50 inches (south) and 0.30 inches (north) will be possible. Flooding is NOT expected today.<\/p>\n<p>Primetime: Noon to 9PM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Friday, July 2nd, 2021 Issue Time: 9:40AM MDT &mdash; A&nbsp;LOW&nbsp;flood threat has been issued for the Southeast Mountains, Raton Ridge and portions of the Front Range, Central Mountains, Urban Corridor and Palmer Ridge The visible satellite imagery below is showing pockets of fog and cloud cover across the eastern plains and in some [&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\/14709"}],"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=14709"}],"version-history":[{"count":3,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/14709\/revisions"}],"predecessor-version":[{"id":14729,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/14709\/revisions\/14729"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=14709"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=14709"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=14709"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}