{"id":6415,"date":"2017-09-17T08:55:25","date_gmt":"2017-09-17T14:55:25","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=6415"},"modified":"2017-09-17T08:55:25","modified_gmt":"2017-09-17T14:55:25","slug":"ftb-09-17-2017-a-few-stronger-storms-for-eastern-colorado","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=6415","title":{"rendered":"FTB 09-17-2017: A Few Stronger Storms for Eastern Colorado"},"content":{"rendered":"<p>Issue Date: Sunday, September 17th, 2017<br>\nIssue Time: 9:00 AM MDT<\/p>\n<p><em>&mdash; Flooding is <strong>NOT<\/strong> expected today<\/em><\/p>\n<p>A couple ingredients will come together for a more active period, and each have been highlighted on the surface map below. First of all, southwesterly flow aloft (red arrow) has increased in the wake of yesterday&rsquo;s exiting <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> and today&rsquo;s approaching <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> disturbance. This has helped to increase moisture across the state as well, pushing <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 near, or just above, normal for the date. At the surface, a quasi-stationary front is draped along the I-25 corridor, allowing moist upslope flow to continue into eastern Colorado. The different flow directions create a &ldquo;turning&rdquo; with height, which will provide the necessary <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> for a few strong-to-<span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;severe thunderstorms&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Thunderstorms that produce a tornado, winds of at least 58 mph (50 kts) and\/or hail at least 1&amp;quot; in diameter.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>severe thunderstorms<\/span> across eastern Colorado today\/tonight.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/09\/SfcObs_20170917.png\"><img loading=\"lazy\" class=\" wp-image-6416 aligncenter\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/09\/SfcObs_20170917.png\" alt=\"\" width=\"501\" height=\"514\"\/><\/a><\/p>\n<p>Across the high country, showers and thunderstorms are expected to be of the garden variety, producing brief periods of rainfall and gusty winds. All activity across the state is expected to move east-northeastward at a decent pace, limiting rainfall in any one location, so <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> is not a concern. For more details, 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, scroll below the map.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/08\/no_threat.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-6157\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/08\/no_threat.png\" alt=\"\" width=\"880\" height=\"580\"\/><\/a><\/p>\n<h3><strong>Zone-Specific Forecasts:<\/strong><\/h3>\n<h4><strong>Urban Corridor, Palmer Ridge, Raton Ridge, Northeast Plains, and 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 are expected, first impacting western areas near the interface with the mountains and moving east-northeastward with time. A few strong-to-severe storms are likely for areas along\/south of I-70, with the main threats being large hail, strong winds, and 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 or two. Brief periods of heavy rain will accompany stronger storms, but storm motions will limit the amount of rainfall in any one location. Due to this, <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> is not a concern, but <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> locations of street flooding in poorly drained areas are possible. Maximum rain rates are as follows:<\/p>\n<p>Urban Corridor: 0.5-0.8 inches\/hour<br>\nPalmer Ridge: 0.5-1.0 inches\/hour<br>\nNortheast Plains, Southeast Plains, and Raton Ridge: 0.8-1.25 inches\/hour<\/p>\n<p>Timing: 1 PM &ndash; 10 PM for the Urban Corridor, Noon &ndash; Midnight for the Raton Ridge, 2 PM &ndash; Midnight for the Palmer Ridge, and 2 PM &ndash; 3 AM for the Southeast Plains and Northeast Plains<\/p>\n<h4><strong>Northern Mountains, Northwest Slope, Front Range, Southeast Mountains, Central Mountains, San Luis Valley, San Juan Mountains, Grand Valley, and Southwest Slope:<\/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, beginning later this morning and continuing into the nighttime hours. A couple showers\/weak thunderstorms may persist into the early morning hours tomorrow over the higher elevations of central Colorado. As mentioned above, storm motions will keep storms from producing <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>, but brief periods of heavy rain will attend the strongest storms. Otherwise, gusty winds and lightning will be the main threats. Maximum rain rates are as follows:<\/p>\n<p>Northwest Slope: 0.05-0.15 inches\/hour<br>\nNorthern Mountains, Front Range, Central Mountains, and Southeast Mountains: 0.5-0.9 inches\/hour<br>\nSan Juan Mountains, Southwest Slope, Grand Valley, and San Luis Valley: 0.4-0.8 inches\/hour<\/p>\n<p>Timing: 11 AM &ndash; 9 PM, with a few lingering showers\/weak thunderstorms into the early morning hours.<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Sunday, September 17th, 2017 Issue Time: 9:00 AM MDT &mdash; Flooding is NOT expected today A couple ingredients will come together for a more active period, and each have been highlighted on the surface map below. First of all, southwesterly flow aloft (red arrow) has increased in the wake of yesterday&rsquo;s exiting <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> [&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\/6415"}],"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=6415"}],"version-history":[{"count":1,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/6415\/revisions"}],"predecessor-version":[{"id":6417,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/6415\/revisions\/6417"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6415"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6415"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6415"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}