{"id":6349,"date":"2017-09-13T10:10:08","date_gmt":"2017-09-13T16:10:08","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=6349"},"modified":"2017-09-13T10:31:37","modified_gmt":"2017-09-13T16:31:37","slug":"ftb-09-13-2017-last-day-under-persistent-ridging-pattern-brings-scattered-showers","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=6349","title":{"rendered":"FTB 09-13-2017: Last Day under Persistent Ridging Pattern Brings Scattered Showers"},"content":{"rendered":"<p>Issue Date: Wednesday, September 13, 2017<br>\nIssue Time: 10:10 AM MDT<\/p>\n<p><em>&mdash; Flooding is <strong>NOT<\/strong> expected today<\/em><\/p>\n<p>Today should be the last day of westerly flow under the ridge that has been persistent for the last several days. As the remnants of Irma continue move to the NE over the next 24 to 36 hours, the ridge will finally be pushed east as the west coast <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> moves over the state. Currently, clear skies across the majority of the state excluding the northern Mountains. With the ridge overhead, this will help increase high temperatures over the lower elevations today. <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>) at Denver and Grand Junction was measured at 0.7 inches and 0.78 inches, respectively. This is still a bit above climatology, but down from the last two days. Less moisture paired with lower <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> and drying in the mid-levels, will cause storms to be high-based and limit rainfall totals when compared to the last couple of days. Gusty winds are likely with stronger storms that form due to the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;Inverted-V&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Refers to the shape of the lower levels of an atmospheric profile. The shape of the &amp;quot;Inverted V&rdquo; is the result of dry air below cloud level, which promotes strong winds and evaporation of precipitation before reaching the surface.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>inverted-V<\/span> soundings.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/09\/wv-20170913.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-6350\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/09\/wv-20170913.png\" alt=\"\" width=\"450\" height=\"300\"\/><\/a><\/p>\n<p>This afternoon, some weak mid-level vorticity will make its way to the state via the west coast <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>. While this will help slightly enhance the upslope flow coverage, the limited atmospheric moisture will prevent <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> rainfall in the mountains. The highest coverage of rainfall is expected to be over the southern Front Range, Palmer Ridge and Southeast Plains. The stronger W\/SW steering winds aloft, will allow storms to move off the mountains and Palmer Ridge into the Southeast Plains. <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> over the Southeast Plains are forecasted to be in the 40s and low 50s (east), so gusty winds are likely for the short duration of the storms. Activity will cease a couple hours after sundown with the decrease in instability. Flooding is not expected today.<\/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>Front Range, Urban Corridor, Northeast Plains, Palmer Ridge, Southeast Mountains, Raton Ridge, Southeast Plains:<\/strong><\/h4>\n<p>Sunny this morning becoming partly cloudy this afternoon. Shower and thunderstorm activity over the mountains will be greatest over the southern Front Range. Some storms are also expected to form due to convergence along the Palmer Ridge. Max 1-hr rain rates up to 0.6 inches with gusty winds possible. Flooding is not expected.<\/p>\n<p>Primetime: 1PM to 10PM<\/p>\n<h4><strong>Northwest Slope, Grand Valley, Southwest Slope, Northern Mountains, Central Mountains, San Luis Valley, San Juan Mountains:<\/strong><\/h4>\n<p>Partly cloudy over the Northern Mountains with sunny skies elsewhere. Higher terrain will become partly cloudy this afternoon with the development of showers and thunderstorms. Highest coverage of rainfall will be in the Northern Mountains, and <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 are expected over the San Juans as well. 24-hour rainfall totals up to 0.3 inches (north) and 0.2 inches (south). Flooding is not expected today.<\/p>\n<p>Primetime: 1PM to 10PM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Wednesday, September 13, 2017 Issue Time: 10:10 AM MDT &mdash; Flooding is NOT expected today Today should be the last day of westerly flow under the ridge that has been persistent for the last several days. As the remnants of Irma continue move to the NE over the next 24 to 36 hours, [&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\/6349"}],"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=6349"}],"version-history":[{"count":8,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/6349\/revisions"}],"predecessor-version":[{"id":6362,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/6349\/revisions\/6362"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6349"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6349"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6349"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}