{"id":8202,"date":"2018-08-25T08:55:59","date_gmt":"2018-08-25T14:55:59","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=8202"},"modified":"2018-08-26T06:53:57","modified_gmt":"2018-08-26T12:53:57","slug":"ftb-08-25-2018-moisture-returns-to-colorado","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=8202","title":{"rendered":"FTB 08-25-2018: Moisture Returns to Colorado"},"content":{"rendered":"<p>Issue Date: 8\/25\/2018<br>\nIssue Time: 9:05 AM<\/p>\n<p><em>A <strong>LOW FLOOD THREAT<\/strong> IS FORECAST TODAY FOR PORTIONS OF THE SOUTHWEST SLOPE, SAN JUAN MOUNTAINS, SOUTHEAST MOUNTAINS, RATON RIDGE, AND SOUTHEAST PLAINS.<\/em><\/p>\n<p>The approach of an 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> from the west (and associate disturbances denoted by red dashed lines) has forced the upper-level ridge eastward, placing Colorado squarely underneath southwest flow aloft for today\/tonight. This has allowed <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> to tick upwards to near, or slightly above, 0.75 inches across the state. This moisture, although confined mainly in the mid-levels, will provide the fuel for showers and thunderstorms today and tonight across the state, with the best coverage south of I-70 coinciding with the best low-level moisture, relatively speaking.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2018\/08\/WV_20180825.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-8203 size-full\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2018\/08\/WV_20180825.png\" alt=\"\" width=\"697\" height=\"505\"\/><\/a><\/p>\n<p>With all of that said, moisture below cloud bases still lacks, so the threat of heavy rainfall is fairly marginal today. Plus, storm motions will be moving at a decent rate to the east-northeast, so it will be difficult for storms to produce rainfall above <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;flash flood&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 flood<\/span> thresholds. Despite these factors, a low flood threat has been issued, mainly for the sensitive burn scars in southern Colorado. Multiple rounds of marginally heavy rainfall may be enough to set off these areas, so the low threat is warranted. For more details on timing and rain rates, please see the zone-specific forecast discussions below.<\/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, jump below the map.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2018\/08\/LFT_20180825.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-8208\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2018\/08\/LFT_20180825.png\" alt=\"\" width=\"880\" height=\"496\"\/><\/a><\/p>\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>Urban Corridor, Palmer Ridge, Northeast Plains, Southeast Plains, and Raton Ridge:<\/strong><\/h4>\n<p><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>-to-<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 expected, with the best coverage south of I-70. Dry air below cloud bases will keep rain rates fairly low, especially along\/near the higher terrain. Further east, near the eastern CO border, a bit more low-level moisture will be present, allowing a couple thunderstorms to become strong-to-severe, producing brief periods of heavy rain, strong winds, and plenty of lightning. Maximum rain rates are as follows:<\/p>\n<p>Urban Corridor and Palmer Ridge: 0.1-0.3 inches\/hour<br>\nRaton Ridge: 0.2-0.35 inches\/hour<br>\nSoutheast Plans and Northeast Plains: 0.6-1.1 inches\/hour<\/p>\n<p>Timing: 1 PM &ndash; 11 PM, with a couple <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> showers\/storms lingering into the early morning hours over the Southeast Plains and Raton Ridge<\/p>\n<h4><strong>Northern Mountains, Northwest Slope, Front Range, Central Mountains, Grand Valley, Southeast Mountains, San Juan Mountains, Southwest Slope, and San Luis Valley:<\/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 are expected today\/tonight, with the first storms of the day popping over the San Juan Mountains and Southwest Slope by 11 AM. Storm motions and dry air below cloud bases will keep most rain rates light, especially for areas north of I-70. The best chance at heavy rainfall will be over the San Juan Mountains, Southwest Slope, and Southeast Mountains, where low-level moisture is best, relatively speaking. The low flood threat is warranted due to the possibility of multiple rounds of thunderstorms in these areas. Maximum rain rates are as follows:<\/p>\n<p>Northwest Slope and Grand Valley: 0.05-0.2 inches\/hour<br>\nNorthern Mountains, Front Range, and Central Mountains: 0.1-0.35 inches\/hour<br>\nSouthwest Slope, San Juan Mountains, and San Luis Valley: 0.4-0.6 inches\/hour<br>\nSan Luis Valley and Southeast Mountains: 0.25-0.5 inches\/hour<\/p>\n<p>Timing: Noon &ndash; 10 PM for locations north of I-70; 11 AM &ndash; Midnight for locations south of I-70, with a couple <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> showers\/weak thunderstorms lingering over the San Juan Mountains and Southeast Mountains into the early morning hours.<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: 8\/25\/2018 Issue Time: 9:05 AM A LOW FLOOD THREAT IS FORECAST TODAY FOR PORTIONS OF THE SOUTHWEST SLOPE, SAN JUAN MOUNTAINS, SOUTHEAST MOUNTAINS, RATON RIDGE, AND SOUTHEAST PLAINS. The approach of an 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> from the west (and associate disturbances denoted by red dashed lines) has forced the upper-level ridge eastward, placing Colorado [&hellip;]<\/p>","protected":false},"author":1,"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\/8202"}],"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\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8202"}],"version-history":[{"count":2,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/8202\/revisions"}],"predecessor-version":[{"id":8209,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/8202\/revisions\/8209"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8202"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8202"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8202"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}