{"id":6599,"date":"2017-09-30T10:26:39","date_gmt":"2017-09-30T16:26:39","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=6599"},"modified":"2017-09-30T10:27:16","modified_gmt":"2017-09-30T16:27:16","slug":"ftb-09-30-2017-widespread-showers-weak-storms-for-higher-terrain-but-rain-rates-limited","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=6599","title":{"rendered":"FTB 09-30-2017: Widespread Showers &#038; Weak Storms For Higher Terrain, But Rain Rates Limited"},"content":{"rendered":"<p>Issue Date: Saturday, September 30, 2017<br>\nIssue Time: 10:30AM MDT<\/p>\n<p><em>&mdash; Flooding is <strong>NOT<\/strong> expected today<\/em><\/p>\n<p><strong><span style=\"color: #ff0000;\">NOTE: This is the last scheduled Flood Threat Bulletin of the 2017 season. However, additional Bulletins may be necessary next week to cover the heavy rainfall threat anticipated in southern\/eastern Colorado.<\/span> <\/strong><\/p>\n<p>A broad 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> continues to be positioned over the western half of the United States, as shown in this morning&rsquo;s water vapor image, below. Despite the many, rather disorganized smaller-scale features, it is apparent that plenty of upward motion is currently occurring east of the <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>&rsquo;s axis in UT, western CO and northern New Mexico. In fact, showers and <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> weak thunderstorms are already occurring in the San Juan Mountains, showing that the system is bringing plenty of dynamical support. From the standpoint of heavy rainfall, the main limiting threat will once again be moisture, along with fast steering winds. This morning&rsquo;s <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>) measurements at Grand Junction and Denver are a rather subdued 0.54 and 0.48 inches, respectively. Higher values approaching 1 inch are found just east of the Colorado border into KS and NE. However, with only a weak easterly component of low-level flow, <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 to remain generally steady across the state.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/09\/wv_markup-13.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-6600\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/09\/wv_markup-13.png\" alt=\"\" width=\"560\" height=\"363\"\/><\/a><\/p>\n<p>With plenty of dynamical support, we expect a round of <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> 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> shower and storm activity coinciding with peak heating this afternoon. Highest coverage will be over the higher terrain, mainly west of the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;Continental 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\"}]'>Continental Divide<\/span>. Rain rates are expected to remain well below flood threat thresholds over most of the state. <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> higher rain rates are possible with storms that come off the Palmer and Cheyenne ridges. However, we expect that even these will stay just below flood threat intensity. Thus, flooding is not expected today. Nonetheless, <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> precipitation totals above 0.25 inches are expected over the central and western part of the state.<\/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>Northeast Plains, Southeast Plains: <\/strong><\/h4>\n<p>Mostly sunny this morning then becoming partly cloudy and breezy 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> showers and thunderstorms this afternoon and evening. Highest coverage will be over western areas, towards the foothills. Max 1-hour rain rates up to 1.2 inches possible with the strongest storm cells, along with gusty winds up to 55 mph. Flooding is not expected today.<\/p>\n<p>Primetime: 2PM to 9PM<\/p>\n<h4><strong>Northwest Slope, Grand Valley, Southwest Slope, Northern Mountains, Central Mountain, San Juan Mountain<\/strong><strong>s, San Luis Valley<\/strong><strong>:<\/strong><\/h4>\n<p>Mostly cloudy and cool with <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> shower and weak thunderstorms increasing in coverage this afternoon. Max 1-hour rainfall up to 0.4 inches (north) and 0.7 inches (far south, along NM border). Snow levels 10,000 feet (north) and 11,500 (south). Gusty winds and small hail could accompany the strongest storms. Flooding is not expected today.<\/p>\n<p>Primetime: 11AM to 10PM, with light rain and snow showers continuing overnight<\/p>\n<h4><strong>Southeast Mountains, Raton Ridge, Front Range, Urban Corridor, Palmer Ridge<\/strong><strong>:<\/strong><\/h4>\n<p>Mostly sunny this morning, then increasing clouds 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 weak thunderstorms developing by early afternoon. Highest coverage will be over the foothills and higher terrain. Max 1-hour rain rates up to 0.75 inches (below 6,000 feet) and 0.6 inches (above 6,000 feet). Snow level will fluctuate around 11,000 feet, lowering later tonight. Gusty winds up to 50 mph and small hail could accompany the strongest cells. Flooding is not expected today.<\/p>\n<p>Primetime: 2PM to 9PM, with light rain and snow showers continuing overnight<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Saturday, September 30, 2017 Issue Time: 10:30AM MDT &mdash; Flooding is NOT expected today NOTE: This is the last scheduled Flood Threat Bulletin of the 2017 season. However, additional Bulletins may be necessary next week to cover the heavy rainfall threat anticipated in southern\/eastern Colorado. A broad 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> continues to be positioned [&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\/6599"}],"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=6599"}],"version-history":[{"count":2,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/6599\/revisions"}],"predecessor-version":[{"id":6602,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/6599\/revisions\/6602"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6599"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6599"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6599"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}