{"id":3521,"date":"2016-08-22T10:27:31","date_gmt":"2016-08-22T16:27:31","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=3521"},"modified":"2016-08-23T08:26:02","modified_gmt":"2016-08-23T14:26:02","slug":"ftb-08-22-2016-scattered-heavy-rainfall-likely-across-southwest","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=3521","title":{"rendered":"FTB 08-22-2016: Scattered Heavy Rainfall Likely Across Southwest"},"content":{"rendered":"<p>Issue Date: Monday, August 22nd, 2016<br>\nIssue Time: 10:24AM MDT<\/p>\n<p><em>&mdash; <strong>MODERATE<\/strong> flood threat for San Juans, Grand Valley and Central Mountains<\/em><br><em> &mdash; <strong>LOW<\/strong> flood threat for Southwest Slope<\/em><\/p>\n<p>Changes are on seen on this morning&rsquo;s weather map, overlaid on the water vapor image below. A large-scale disturbance, with its center located over British Columbia, is carrying a long <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> that extends southward through the Mexico border. Of importance for Colorado is the southern fringe of this activity, which is being maintained by a strong subtropical <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>. As the disturbance moves east today, it will promote <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> lift and thus, shower and thunderstorm activity west of the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;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\"}]'>Divide<\/span>. Some of this can already been seen on morning radar and visible satellite loops across UT and western CO. <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> values have jumped from below 0.4 inches to over 0.8 inches at Grand Junction and Durango. North of the San Juans, most of this moisture is found above the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;boundary layer&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;&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&amp;lt;br \/&amp;gt;&amp;lt;p&amp;gt;&amp;lt;span style=&amp;quot;color: #ffffff;&amp;quot;&amp;gt;The lower portion of the atmosphere that is directly influenced by the earth&amp;#039;s surface. Primarily, the boundary layer is driven by solar heating during the day and radiational cooling at night.&amp;lt;\/span&amp;gt;&amp;lt;\/p&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>boundary layer<\/span> so it will take several hours before moisture is transported to the surface through rainfall and moisture transport from the south. However, <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> temperatures at or over 50F are found just south of the NM\/CO border so there is a nearby source of higher moisture. Despite marginal instability today, convective temperatures will be reached with help from dynamical forcing. Numerical weather prediction guidance suggests moderate to high probabilities of exceeding 1 inch of rainfall across the southwest, and there is no reason to doubt this given the overall pattern. In all, a Moderate flood threat is in place for parts of the San Juans and Central Mountains, with a Low flood threat surrounding those areas. The main impact will be from heavy rainfall at durations of 30-minutes to 3-hours.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2016\/08\/wv_markup4.png\"><img loading=\"lazy\" class=\"aligncenter  wp-image-3532\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2016\/08\/wv_markup4.png\" alt=\"wv_markup\" width=\"565\" height=\"369\"\/><\/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.<br><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2016\/08\/FTB_20160822.png\"><img loading=\"lazy\" class=\"aligncenter  wp-image-3541\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2016\/08\/FTB_20160822.png\" alt=\"FTB_20160822\" width=\"867\" height=\"488\"\/><\/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<div>\n<h3><strong>Zone-Specific Forecasts:<\/strong><\/h3>\n<p><strong>San Juan Mountains, Southwest Slope, Grand Valley, Central Mountains:<\/strong><\/p>\n<p>Mostly 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> showers giving way to <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> showers thunderstorms developing by early afternoon. Max 30-min rain rates up to 0.7 inches,1-hour rain rates up to 1.1 inch and 3-hour rates up to 2.4 inches are possible. A Moderate flood threat has been posted for parts of the regions with a Low flood threat surrounding that region. Hail up to 0.5 inches may accompany the stronger cells.<\/p>\n<p>Primetime: 1PM to 9PM<\/p>\n<p><strong>Northwest Slope, Northern Mountains, San Luis Valley:<\/strong><\/p>\n<p>Partly cloudy early then <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 weak thunderstorms developing by early afternoon. Maximum 1-hour rain rates up to 0.6 inches are possible, with maximum 24-hour rainfall up to 1 inch. Flooding is not expected today.<\/p>\n<p>Primetime: 1PM to 7:30PM<\/p>\n<p><strong>Southeast Plains:<\/strong><\/p>\n<p>Sunny early, then partly cloudy 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> 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> thunderstorms possible. Max 1-hour rainfall up to 1.4 inches is possible. However, flooding is not expected today. Hail up to 1.25 inch may accompany the strongest storms.<\/p>\n<p>Primetime: 3PM to 9PM<\/p>\n<p><strong>Front Range, Urban Corridor, Palmer Ridge, Northeast Plains, Southeast Mountains, Raton Ridge:<\/strong><\/p>\n<p>Mostly sunny early and continued warm. <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 are possible across higher terrain and foothills. Max 1-hour rain rates up to 0.5 inches are possible. However, flooding is not expected.<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Monday, August 22nd, 2016 Issue Time: 10:24AM MDT &mdash; MODERATE flood threat for San Juans, Grand Valley and Central Mountains &mdash; LOW flood threat for Southwest Slope Changes are on seen on this morning&rsquo;s weather map, overlaid on the water vapor image below. A large-scale disturbance, with its center located over British Columbia, [&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\/3521"}],"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=3521"}],"version-history":[{"count":6,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/3521\/revisions"}],"predecessor-version":[{"id":3544,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/3521\/revisions\/3544"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3521"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3521"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3521"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}