{"id":5800,"date":"2017-08-05T10:40:49","date_gmt":"2017-08-05T16:40:49","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=5800"},"modified":"2017-08-06T07:45:47","modified_gmt":"2017-08-06T13:45:47","slug":"ftb-08-05-2017-active-pattern-to-continue-supporting-isolated-heavy-rainfall","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=5800","title":{"rendered":"FTB 08-05-2017: Active Pattern To Continue Supporting Isolated Heavy Rainfall"},"content":{"rendered":"<p>Issue Date: Saturday, August 5, 2017<br>\nIssue Time: 10:45AM MDT<\/p>\n<p><em>&mdash; <strong>LOW<\/strong> flood threat for Northeast Plains, Urban Corridor, San Juans, Southwest Slope, Grand Valley, Northwest Slope<\/em><\/p>\n<p>As mentioned in previous Flood Threat Bulletins and Outlooks, an active weather pattern has setup across Colorado. The central feature supporting this is the large-scale <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> located across the US Great Plains. As shown in this morning&rsquo;s water vapor image below, a weak <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;jet stream&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Relatively strong winds concentrated within a narrow stream in the atmosphere. General weather patterns are related closely to the position, strength and orientation of the jet stream.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>jet stream<\/span> lies just north of Colorado. Within it and in close proximity are <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> ripples, or shortwaves (or even mini-shortwaves) that are supporting mid to high level clouds this morning. In particular, the feature in southwest Colorado is likely a remnant of yesterday&rsquo;s <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> and will be a factor in supporting heavy rainfall as instability develops this afternoon over the western slope. Moisture is somewhat lower today across central Colorado with <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> (<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>) as low as 0.6 inches. However, <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> greater than 1 inch is found in far eastern Colorado as well as the western parts of the state. This morning&rsquo;s Grand Junction sounding showed a <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> of 1.03, which is above normal for this time of year. Steady to slightly increasing <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> is expected in western Colorado due to moisture <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;advection&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The process of transport of an atmospheric property, typically temperature or moisture in our FTB discussions, by the wind. &amp;quot;Strong&rdquo; or &amp;quot;weak&rdquo; advection refers to the rate of change of the advected property&amp;#039;s value at a given point.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>advection<\/span> from the west.<\/p>\n<p>At the surface, a high pressure cell was located over southwest Colorado, which will promote some enhanced low-level moisture <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;advection&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The process of transport of an atmospheric property, typically temperature or moisture in our FTB discussions, by the wind. &amp;quot;Strong&rdquo; or &amp;quot;weak&rdquo; advection refers to the rate of change of the advected property&amp;#039;s value at a given point.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>advection<\/span> into western facing foothills of the San Juans, Elk Mts. And Grand Mesa. Much like yesterday, we expect <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 this afternoon. A Low flood threat has been posted, mainly for mud flows and debris slides. Farther east, <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;downsloping&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Refers to the winds that blow from higher elevations down towards lower elevations. As air parcels descend, they warm, which often results in rapid warming of areas near the higher terrains. It also promotes lower relative humidity values and stability, which prevents thunderstorm development.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>downsloping<\/span> flow will once again prevail closer to the mountains. However, a weak boundary is expected to develop along the South Platte River this afternoon. As storms form of the Cheyenne Ridge, they will move southeast and encounter higher instability and higher moisture. The strongest cells will have the potential to produce heavy short-term rainfall, and 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>. Large hail will also be possible with these cells.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/08\/wv_markup-3.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-5801\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/08\/wv_markup-3.png\" alt=\"\" width=\"650\" height=\"345\"\/><\/a><\/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 (hover over threat areas for more details). For Zone-Specific forecasts, scroll below the map.<\/p>\n<div style=\"position: relative;\"><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/08\/FTB-8-5-2017-old.png\"><img loading=\"lazy\" class=\"alignnone wp-image-5806\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/08\/FTB-8-5-2017-old.png\" alt=\"\" width=\"880\" height=\"499\"\/><\/a><\/div>\n<div><img loading=\"lazy\" class=\"alignright wp-image-135\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/04\/floodthreat_legend2.png\" alt=\"Flood Threat Legend\" width=\"275\" height=\"71\"\/><\/div>\n<h3><strong>Zone-Specific Forecasts:<\/strong><\/h3>\n<h4><strong>Front Range, Urban Corridor, Palmer Ridge, Northeast Plains, Southeast Mountains, Raton Ridge, Southeast Plains:<\/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> showers and thunderstorms developing by early afternoon. Highest coverage will be over the Northeast Plains as well as in the Southeast Mountains\/Raton Ridge. Max 1-hr rain rates up to 1.8 inches over northeast areas and up to 0.9 inches in southern areas. 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> in the Northeast Plains and surrounding areas. Large hail up to 1.5 inches and gusty winds up to 65 mph could accompany the strongest cells.<\/p>\n<p>Primetime: 1PM to 10PM<\/p>\n<h4><strong>Northwest Slope, Grand Valley, Southwest Slope, Northern Mountains, Central Mountains, San Juan Mountains, San Luis Valley:<\/strong><\/h4>\n<p>Partly cloudy early with <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 by afternoon. Highest coverage will be over western foothills where moisture is higher, specifically the San Juans, Elk Mountains, Grand Mesa and Roan Plateau. Max 1-hour rainfall up to 1.1 inches (max 30-min up to 0.7) will support <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> mud flows and debris slides. Gusty winds up to 50 mph could accompany the strongest cells. Activity will quickly subside after sunset.<\/p>\n<p>Primetime: 12PM to 8PM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Saturday, August 5, 2017 Issue Time: 10:45AM MDT &mdash; LOW flood threat for Northeast Plains, Urban Corridor, San Juans, Southwest Slope, Grand Valley, Northwest Slope As mentioned in previous Flood Threat Bulletins and Outlooks, an active weather pattern has setup across Colorado. The central feature supporting this is the large-scale <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> located across [&hellip;]<\/p>","protected":false},"author":4,"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\/5800"}],"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=5800"}],"version-history":[{"count":3,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/5800\/revisions"}],"predecessor-version":[{"id":5809,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/5800\/revisions\/5809"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5800"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5800"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5800"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}