{"id":15904,"date":"2021-09-03T10:27:03","date_gmt":"2021-09-03T16:27:03","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=15904"},"modified":"2021-09-04T08:13:16","modified_gmt":"2021-09-04T14:13:16","slug":"ftb-09-03-2021-flood-threat-continues-east-with-another-overnight-threat-forecast","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=15904","title":{"rendered":"FTB 09-03-2021: Flood Threat Continues East with Another Overnight Threat Forecast"},"content":{"rendered":"<p>Issue Date: Friday, September 3rd, 2021<br>\nIssue Time: 10:25AM MDT<\/p>\n<p><em>&mdash; <\/em><em>A&nbsp;<\/em><strong><em>LOW&nbsp;<\/em><\/strong><em>flood threat has been issued for the Urban Corridor, Northeast Plains, Palmer Ridge &amp; Southeast Plains<\/em><br><em><span style=\"color: #ff0000;\">&mdash;<\/span> <span style=\"color: #ff0000;\">This is an overnight flood threat<\/span><\/em><\/p>\n<p>The upper-level <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 continue to approach from the west today and turn this morning&rsquo;s southwesterly flow aloft more westerly by this afternoon. This should continue to scour out any remaining surface moisture over the western portion of the state and limit 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>, high-based storm coverage to the high terrains and elevated plateaus. As the <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> approaches, the upper-level winds are also expected to pick up just north of the border. This should keep storms moving relatively quickly that develop over the Northern\/Central Mountains and Front Range. Together, these two forecast elements should effectively limit the flood threat over the area.<\/p>\n<p>For the most part, as the mountain storms are steered into the adjacent plains with the westerly flow, they will likely be moving too quickly to cause more than nuisance flooding issues. However, a couple <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 may be possible over the Palmer Ridge where some better surface moisture can hang on with increased dynamics, so a LOW flood threat has been issued for the area. As the storms continue to move east and southeast and into higher moisture over the plains, the <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> is expected to &ldquo;line out&rdquo; and become 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>. With decent <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;shear&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Local variation of the wind, either in the horizontal or vertical direction.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>shear<\/span> over the area, the storm complex is anticipated to intensify, and storms may be capable of producing severe weather which includes large hail, damaging winds and dangerous lightning. Due to the anticipated increased of rain rates over the area with the higher moisture, a LOW flood threat has been issued.<\/p>\n<p>Finally, another moisture axis looks like it will set up over the Southeast Plains today and lasts through the overnight hours. With possible boosted lift from the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;low-level jet&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A jet stream that is typically found in the lower 2&ndash;3 km of the atmosphere. At night, this may be referred to as the &amp;quot;nocturnal jet&rdquo; and help sustain storms.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>low-level jet<\/span> tonight across the southern border and enhanced convergence along this boundary, <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 may develop over the Southeast Plains tonight. With <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> around 60F or slightly above, the storms would have the potential to cause local heavy rainfall and flooding issues, so the&nbsp;LOW flood threat continues overnight.<\/p>\n<p><img loading=\"lazy\" class=\"aligncenter wp-image-15905\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/09\/vis_20210903.png\" alt=\"\" width=\"650\" height=\"425\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/09\/vis_20210903.png 1322w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/09\/vis_20210903-300x196.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/09\/vis_20210903-768x502.png 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/09\/vis_20210903-1024x669.png 1024w\" sizes=\"(max-width: 650px) 100vw, 650px\"\/><\/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\/09\/FTB_20210903_snap.jpeg\"><img loading=\"lazy\" class=\"wp-image-15911 aligncenter\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/09\/FTB_20210903_snap-1024x690.jpeg\" alt=\"\" width=\"891\" height=\"600\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/09\/FTB_20210903_snap-1024x690.jpeg 1024w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/09\/FTB_20210903_snap-300x202.jpeg 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/09\/FTB_20210903_snap-768x518.jpeg 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/09\/FTB_20210903_snap.jpeg 1780w\" sizes=\"(max-width: 891px) 100vw, 891px\"\/><\/a><\/p>\n<h3><strong>Zone-Specific Forecasts:<\/strong><\/h3>\n<h4><strong>Southeast Plains, Northeast Plains, Southeast Mountains, Front Range, Raton Ridge, Urban Corridor &amp; Palmer Ridge:<\/strong><\/h4>\n<p>Faster moving storms should help limit the flood threat today back to the west today. However, <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 may be possible in a pool of moisture over the Palmer Ridge with enhanced convergence, so a LOW flood threat has been issued. Max 1-hour rain rates up to 1.25 inches with local storm totals up to 2 inches may&nbsp;be possible. As storms move east, they will likely form a line and be capable of producing large hail and damaging wind gusts along with lightning and heavy rainfall. An <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> tornado may be possible (south). With max 1-hour rain rates forecast up to 2.25 inches, a LOW flood threat has been issued. It&rsquo;s possible for&nbsp;another round of overnight storms across the Southeast Plains, and <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 may cause 3-hour rain rates up to 3.50 inches, so the LOW flood threat continues into the overnight hours for this area. Flood threats today include road, local stream and arroyo flooding as well as heavy field ponding.<br>\nPrimetime: 3PM to 6AM<\/p>\n<h4><strong>San Juan Mountains, Southwest Slope, Central Mountains, San Luis Valley, Grand Valley, Northwest Slope &amp; Northern Mountains:<\/strong><\/h4>\n<p>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 over western Colorado mountains and elevated plateaus are expected to favor the northern\/central regions with more <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> pops further south. Max 1-hour rain rates up to 0.25 inches are forecast with <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> storm totals up to 0.50 inches possible. Flooding is NOT forecast today, and activity should come to an end by the evening hours.<br>\nPrimetime: 1PM to 9PM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Friday, September 3rd, 2021 Issue Time: 10:25AM MDT &mdash; A&nbsp;LOW&nbsp;flood threat has been issued for the Urban Corridor, Northeast Plains, Palmer Ridge &amp; Southeast Plains &mdash; This is an overnight flood threat The upper-level <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 continue to approach from the west today and turn this morning&rsquo;s southwesterly flow aloft more westerly by [&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\/15904"}],"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=15904"}],"version-history":[{"count":4,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/15904\/revisions"}],"predecessor-version":[{"id":15913,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/15904\/revisions\/15913"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15904"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15904"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15904"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}