{"id":12787,"date":"2020-08-16T09:21:23","date_gmt":"2020-08-16T15:21:23","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=12787"},"modified":"2020-08-17T07:13:44","modified_gmt":"2020-08-17T13:13:44","slug":"ftb-08-16-2020-slow-moving-storms-in-a-high-moisture-environment-returns-the-flood-threat-to-the-eastern-plains","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=12787","title":{"rendered":"FTB 08-16-2020: Slow Moving Storms in a High Moisture Environment Returns the Flood Threat to the Eastern Plains"},"content":{"rendered":"<p>Issue Date: Sunday, August 16th, 2020<br>\nIssue Time: 9:20AM MDT<\/p>\n<p><em>&mdash; A <strong>LOW<\/strong> flood threat has been issued for the Northeast Plains, Southeast Plains, eastern Palmer Ridge, and eastern Raton Ridge. This threat also includes the Spring Creek burn area.<\/em><\/p>\n<p>Lots of smoke is still trapped under the ridge, and it&rsquo;s very <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> and thick over the eastern plains (marked below). The High will continue to strengthen over the Great Basin today, which will keep high temperatures on the rise over the western half of the state and hot temperatures in the forecast statewide. It&rsquo;s still pretty dry over the western slope and Northern\/Central Mountains, as seen by the cloud free conditions, so precipitation chances will continue to be near zero. A little moisture looks like it will combine with some mid-level energy over the San Juan Mountains, so expect another round of high-based showers over the eastern\/southern San Juan Mountains this afternoon with slightly higher totals when compared to yesterday.<\/p>\n<p><img loading=\"lazy\" class=\"aligncenter wp-image-12788 size-full\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/vis_20200816.png\" alt=\"\" width=\"646\" height=\"450\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/vis_20200816.png 646w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/vis_20200816-300x209.png 300w\" sizes=\"(max-width: 646px) 100vw, 646px\"\/><\/p>\n<p>Over the Southeast Mountains, chances for precipitation also increase today. The slow-moving storms will be capable of producing <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> totals around 0.75 inches, which could be problematic if one forms over the Spring Creek burn area, so a Low flood threat has been issued. About a quarter of an inch fell yesterday on the southern portion of the burn area (gauge observation), which caused <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> and a debris flow onto Highway 12. This seems to be the most sensitive area of the scar.<\/p>\n<p>A convergence boundary (weak cold front) will set up over the eastern plains and Raton Ridge this afternoon, which could spark some <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> storms. Less <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> and a lack of a noticeable <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> moving through the flow today means that storm coverage will be less and storms should be weaker when compared to yesterday. However, the slow steering winds will still allow the smaller storm cores to drop some heavy rainfall if they can break through 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>. Thus, the Low flood threat has been re-issued 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> forecast in the 60Fs 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> just over 1 inch. Rainfall should start to end a couple hours after sundown.<\/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\/2020\/08\/FTB_20200816_snap.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-12800\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/FTB_20200816_snap.png\" alt=\"\" width=\"880\" height=\"590\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/FTB_20200816_snap.png 893w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/FTB_20200816_snap-300x201.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/08\/FTB_20200816_snap-768x515.png 768w\" sizes=\"(max-width: 880px) 100vw, 880px\"\/><\/a><\/p>\n<h3><strong>Zone-Specific Forecasts:<\/strong><\/h3>\n<h4><strong>Front Range, Urban Corridor, Palmer Ridge, Southeast Mountains, Northeast Plains, Southeast Plains, <\/strong><strong>San Luis Valley, <\/strong><strong>&amp; Raton Ridge:<\/strong><\/h4>\n<p>Upslope flow will cause 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> storms to form over the Southeast Mountains today, and southerly steering flow could push a few storms into the San Luis Valley where morning totals up to 0.25 inches will be possible. <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> totals over the Southeast Mountains could reach 0.75 inches, so a Low flood threat has been issued for the Spring Creek burn area. 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> storms are forecast over the Palmer Ridge and southern Front Range with totals up to 0.90 inches possible. Storms that move south, just off the foothills, could produce some severe hail again as well. Further north, a storm or two could form over the northern Front Range, but rain rates should remain around 0.50 inches with no rainfall again for the Denver Metro area.<\/p>\n<p>Over the eastern plains, expect some more intense storms as parameters are more favorable with the stronger southeasterly surface winds. Still a chance a few storms could become severe that form along the convergence boundary, but the threat is lower than yesterday. The main threats from the severe storms that develop include heavy rainfall, large 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. A weak tornado could also be possible with extra spin along the front. With max 1-hour rain rates up to 1.75 inches possible, a Low flood threat has been issued.<\/p>\n<p>Primetime: 1:30PM to 11PM<\/p>\n<h4><strong>San Juan Mountains, Central Mountains, Northern Mountains, Southwest Slope, Northwest Slope, <\/strong><strong>&amp; <\/strong><strong>Grand Valley: <\/strong><\/h4>\n<p>Looking like there&rsquo;s still some mid-level moisture over the eastern\/southern San Juan Mountains. This will spark another round of storms and some mid-level energy could help slightly increase totals and coverage when compared to yesterday. <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>, totals up to 0.40 inches will be possible. Dry everywhere else with hot temperatures forecast again. Warmer temperatures near surface in today&rsquo;s Grand Junction sounding and the HRRR Smoke indicate the smoke will take longer to mix out, so expect less near surface visibility with poor air quality.<\/p>\n<p>Primetime: 1:30PM to 8PM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Sunday, August 16th, 2020 Issue Time: 9:20AM MDT &mdash; A LOW flood threat has been issued for the Northeast Plains, Southeast Plains, eastern Palmer Ridge, and eastern Raton Ridge. This threat also includes the Spring Creek burn area. Lots of smoke is still trapped under the ridge, and it&rsquo;s very <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> and thick [&hellip;]<\/p>","protected":false},"author":8,"featured_media":0,"comment_status":"open","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\/12787"}],"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=12787"}],"version-history":[{"count":5,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/12787\/revisions"}],"predecessor-version":[{"id":12802,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/12787\/revisions\/12802"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12787"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12787"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12787"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}