{"id":14784,"date":"2021-07-05T14:06:21","date_gmt":"2021-07-05T20:06:21","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=14784"},"modified":"2021-07-08T10:02:31","modified_gmt":"2021-07-08T16:02:31","slug":"fto-07-05-2021-one-day-elevated-flood-threat-before-a-drying-trend-begins","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=14784","title":{"rendered":"FTO 07-05-2021: One Day Elevated Flood Threat Before A Drying Trend Begins"},"content":{"rendered":"<p>Issue Date: Monday,&nbsp;July 5th, 2021<br>\nIssue Time: 2:05PM MDT<br>\nValid Dates:&nbsp;7\/6 &ndash; 7\/20<\/p>\n<p><img loading=\"lazy\" class=\"aligncenter wp-image-14789\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/Screen-Shot-2021-07-05-at-1.49.53-PM.png\" alt=\"\" width=\"880\" height=\"127\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/Screen-Shot-2021-07-05-at-1.49.53-PM.png 2620w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/Screen-Shot-2021-07-05-at-1.49.53-PM-300x43.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/Screen-Shot-2021-07-05-at-1.49.53-PM-768x111.png 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/Screen-Shot-2021-07-05-at-1.49.53-PM-1024x148.png 1024w\" sizes=\"(max-width: 880px) 100vw, 880px\"\/><\/p>\n<p>There will be one more day with an Elevated flood threat (Event #1) before a drying trend begins into next weekend. The High, currently located over the four-corner region, will begin to build again over Utah and Arizona after the passage of a cold front on Tuesday. While cooler temperatures are forecast behind the front on Wednesday (east), <em><strong>hot<\/strong><\/em> temperatures are expected return statewide under the building ridge by Thursday. Daily rounds of <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> storms over the mountains are expected for Event #2. The north and northwesterly flow aloft at the latter end of Event #2 may allow for a disturbance or two to move through the flow. These disturbances&nbsp;could slightly cool down daily high temperatures a couple degrees and create a low-end localized flood threat. So, be sure to follow the daily FTB, which will track each of these potential disturbances individually.<\/p>\n<p><img loading=\"lazy\" class=\"aligncenter wp-image-14786\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/wv_20210705.png\" alt=\"\" width=\"750\" height=\"437\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/wv_20210705.png 1592w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/wv_20210705-300x175.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/wv_20210705-768x448.png 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/wv_20210705-1024x597.png 1024w\" sizes=\"(max-width: 750px) 100vw, 750px\"\/><\/p>\n<p>Generally speaking, even with the drying trend, there should still be plenty of residual moisture for <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> storms over the mountains each afternoon and evening through next weekend (Event #2). This is the time of year, climatologically, that there is the largest uptick in <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> (statewide), so base moisture generally increases. Storms that develop during Event #2 are expected to favor the southern high terrains, areas along and near 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>, and eastern ridge, so expect the highest accumulations in these regions.<\/p>\n<p>The <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> plumes below show that moisture is forecast to drop off drastically over western Colorado by Saturday (right image). So, over the weekend, accumulating rainfall over the San Juan and Central Mountains won&rsquo;t be as likely. With <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 or near normal over eastern Colorado, better coverage of storms is expected over the eastern mountains. At this time there is No Apparent flood threat issued.<\/p>\n<p><img loading=\"lazy\" class=\"aligncenter wp-image-14787\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/PW_20210705.png\" alt=\"\" width=\"880\" height=\"308\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/PW_20210705.png 2038w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/PW_20210705-300x105.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/PW_20210705-768x269.png 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/PW_20210705-1024x359.png 1024w\" sizes=\"(max-width: 880px) 100vw, 880px\"\/><\/p>\n<p>Event #3 should begin sometime next week as the ridge gets squashed\/flattened by a series of disturbances. The <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;zonal&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;refers to the east-west direction; usually used to describe atmospheric flow that roughly follows lines of latitude&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>zonal<\/span> flow that is expected to develop will likely move daily disturbances across the state, which will enhance lift. Moisture will likely increase as well with the High being suppressed both south and west during this period. While this event is still far out, meaning lower confidence in the forecast details, the ridge should begin to build back over the west during the tail end of&nbsp;Event #3. As this occurs, it will be our next shot at a&nbsp;<span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;monsoon&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;a seasonal wind that brings moisture and rain to the region into which it blows; there is also a dry phase to monsoons, but popular usage refers only to the wet phase; these winds occur in many places around the world, and where they occur they are responsible for a majority of that location&rsquo;s annual precipitation&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>monsoon<\/span> moisture surge, so an Elevated flood threat has been issued. No map has been drawn below for Event #3 due to low confidence in the rainfall placement.<\/p>\n<p>Keep scrolling below to read more details about each of the events.<\/p>\n<h3><strong>Event #1:<\/strong> <strong>Tuesday<\/strong><strong> (<\/strong><strong>7\/6<\/strong><strong>)<\/strong><\/h3>\n<h4><strong><span style=\"color: #ff6600;\">Elevated flood threat<\/span> <\/strong><strong>for eastern Colorado as <\/strong><strong>above average moisture and a <\/strong><strong>front<\/strong><strong>al boundary<\/strong> <strong>combine for widespread storm coverage, including some severe storms<\/strong><strong>.<\/strong><\/h4>\n<p>Heavy rainfall over the mountains and adjacent plains from slow moving and <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;training&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Continuous or repeated rainfall over the same region&nbsp;in a relatively short time span. Training thunderstorms can produce very high rainfall totals and cause flash flooding.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>training<\/span> storms is expected for one more day on Tuesday. Moisture looks like it will start to decrease over western Colorado by this evening, so looking more to the eastern mountains for the potential flood threat tomorrow. Most likely, the heavy rainfall producing storms will be over the southern Front Range and Southeast Mountains. In additional to rainfall over the mountains, some severe storms could develop along a boundary over the Southeast Plains. Max 1-hour rain rates up to 2.25 inches (east) and 1.25 inches (west) may be possible. For the severe storms, large hail, wind and perhaps a weak tornado. Over the steeper terrains, excessive runoff will be likely again with the saturated soils, and there will likely be an increased risk for mud flows and debris slides. Field ponding, arroyo flooding and road flooding will all be possible over the plains.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTO_20210705_e1.png\"><img loading=\"lazy\" class=\"alignnone  wp-image-14840\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTO_20210705_e1.png\" alt=\"\" width=\"889\" height=\"601\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTO_20210705_e1.png 896w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTO_20210705_e1-300x203.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTO_20210705_e1-768x519.png 768w\" sizes=\"(max-width: 889px) 100vw, 889px\"\/><\/a><\/p>\n<h3><strong>Event #2: <\/strong><strong>Thursday<\/strong><strong> &ndash; <\/strong><strong>Monday<\/strong><strong> (<\/strong><strong>7\/8<\/strong><strong> &ndash; <\/strong><strong>7\/12<\/strong><strong>)<\/strong><\/h3>\n<h4><span style=\"color: #0000ff;\"><strong>No Apparent<\/strong><\/span><strong><span style=\"color: #0000ff;\"> flood threat<\/span> as <\/strong><strong>daily rounds of mountain precipitation develop with residual moisture under a building ridge<\/strong><strong>.<\/strong><\/h4>\n<p>Finally, a break from the well above normal moisture is on its way, which&nbsp;should help the eastern mountains dry out a bit. For Event #2 there is No Apparent flood threat issued as daily rounds of high-elevation precipitation will likely develop with residual moisture under the ridge through this weekend. A couple of the days could see storms develop over the eastern ridges as well. For the most part, the rainfall looks to be higher in coverage south, and accumulations should mostly along and near 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>. Should a disturbance move through eastern Colorado during the latter part of Event #2, and be timed with the peak in afternoon heating, a localized flood threat may become an issue. Be sure to follow the daily FTB, which will better track these subtle features.<br><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTO_20210705_e2.png\"><img loading=\"lazy\" class=\"alignnone  wp-image-14841\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTO_20210705_e2.png\" alt=\"\" width=\"889\" height=\"603\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTO_20210705_e2.png 895w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTO_20210705_e2-300x203.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTO_20210705_e2-768x521.png 768w\" sizes=\"(max-width: 889px) 100vw, 889px\"\/><\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Monday,&nbsp;July 5th, 2021 Issue Time: 2:05PM MDT Valid Dates:&nbsp;7\/6 &ndash; 7\/20 There will be one more day with an Elevated flood threat (Event #1) before a drying trend begins into next weekend. The High, currently located over the four-corner region, will begin to build again over Utah and Arizona after the passage of [&hellip;]<\/p>","protected":false},"author":8,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[3],"tags":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/14784"}],"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=14784"}],"version-history":[{"count":5,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/14784\/revisions"}],"predecessor-version":[{"id":14843,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/14784\/revisions\/14843"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=14784"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=14784"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=14784"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}