{"id":15796,"date":"2021-08-29T10:17:18","date_gmt":"2021-08-29T16:17:18","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=15796"},"modified":"2021-08-30T08:16:54","modified_gmt":"2021-08-30T14:16:54","slug":"ftb-08-29-2021-cooler-day-ahead-for-eastern-co-with-scattered-post-frontal-mountain-storms-south","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=15796","title":{"rendered":"FTB 08-29-2021: Cooler Day Ahead for Eastern CO with Scattered, Post-Frontal Mountain Storms South"},"content":{"rendered":"<p>Issue Date: Sunday, August 29th, 2021<br>\nIssue Time: 10:15AM MDT<\/p>\n<p><em>&mdash; <\/em><em>A&nbsp;<\/em><strong><em>LOW<\/em><\/strong><em>&nbsp;flood threat has been issued for the Front Range, Urban Corridor and western Palmer Ridge<\/em><\/p>\n<p>It&rsquo;s a cool and cloudy start to the morning over eastern CO behind yesterday&rsquo;s cold front. Morning temperatures are running around 8-12F cooler than this time yesterday for most locations. Lower-level moisture has also returned behind the front, and <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 was measured at 0.86 inches. Also noticeable in the sounding was a strong <span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;cap&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The area where a parcel of air has negative buoyancy or sinks. The intensity of the cap is measured by its convective inhibition. If the cap is sufficiently large, it may prevent thunderstorms from forming at all.&lt;\/div&gt;\"  data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>cap<\/span> right above 700mb, which will help to limit the chance for precipitation north today. The front has had little affect over western CO where <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> remains around 0.40 inches. It is likely that <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> near the southern border is probably slightly higher, so another round of diurnally driven, <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 will be possible over the southern San Juan Mountains. Otherwise, it should remain dry with smoky conditions continuing.<\/p>\n<p><img loading=\"lazy\" class=\"aligncenter wp-image-15797\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/vis_20210829.png\" alt=\"\" width=\"800\" height=\"474\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/vis_20210829.png 1266w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/vis_20210829-300x178.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/vis_20210829-768x455.png 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/vis_20210829-1024x607.png 1024w\" sizes=\"(max-width: 800px) 100vw, 800px\"\/><\/p>\n<p>Flow aloft across the state will be <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> behind 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>, and only minimal mid-level energy is forecast to move through this flow. That means the <span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;cap&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The area where a parcel of air has negative buoyancy or sinks. The intensity of the cap is measured by its convective inhibition. If the cap is sufficiently large, it may prevent thunderstorms from forming at all.&lt;\/div&gt;\"  data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>cap<\/span> will likely not be broken over the northern portion of the Front Range\/Urban Corridor. Best chances for post-frontal upslope flow storms to develop will be over the southern Front Range\/Palmer Ridge intersect, Southeast Mountains and western Raton Ridge where clearing began earlier in the day. There is a chance for a stronger storm or two to develop over the Palmer Ridge\/southern Front Range, if mid-level energy with decent&nbsp;daytime heating can break the <span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;cap&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The area where a parcel of air has negative buoyancy or sinks. The intensity of the cap is measured by its convective inhibition. If the cap is sufficiently large, it may prevent thunderstorms from forming at all.&lt;\/div&gt;\"  data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>cap<\/span>. Guidance this morning is showing higher&nbsp;confidence in this solution. With the increase in low-level moisture&nbsp;behind the front and slower steering flows aloft,&nbsp;if storms develop, heavy rainfall and localized flooding issues would likely accompany them. So, a LOW flood threat has been issued for this possibility. Elsewhere, rain rates from storms today should be on the lower end, so flooding is not expected.<\/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. If there is a threat, hover over the threat areas for more details, and click on burn areas to learn more about them. For Zone-Specific forecasts, scroll below the threat map.<br><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/FTB_20210829_snap.jpeg\"><img loading=\"lazy\" class=\"alignnone  wp-image-15812\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/FTB_20210829_snap-1024x689.jpeg\" alt=\"\" width=\"894\" height=\"601\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/FTB_20210829_snap-1024x689.jpeg 1024w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/FTB_20210829_snap-300x202.jpeg 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/FTB_20210829_snap-768x517.jpeg 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/08\/FTB_20210829_snap.jpeg 1780w\" sizes=\"(max-width: 894px) 100vw, 894px\"\/><\/a><\/p>\n<h4><strong>Front Range, San Juan Mountains, Southeast Mountains, Palmer Ridge, Raton Ridge, Urban Corridor, Northeast Plains &amp; Southeast Plains:<\/strong><\/h4>\n<p>Best chance for post-frontal upslope flow storm development today will be over the western Palmer Ridge, southern Front Range, Southeast Mountains and western Raton Ridge. If a storm can break through the&nbsp;<span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;cap&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The area where a parcel of air has negative buoyancy or sinks. The intensity of the cap is measured by its convective inhibition. If the cap is sufficiently large, it may prevent thunderstorms from forming at all.&lt;\/div&gt;\"  data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>cap<\/span> over the Palmer Ridge\/Front Range intersect, heavy rainfall will be possible with max 1-2&nbsp;hour rainfall totals up to 1.40 inches. A LOW flood threat has been issued for this reason. Elsewhere, rainfall rates should&nbsp;be more gradual with storm totals just under an inch possible. Additional mountain, <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 will likely form over the southern San Juan Mountains where max 1-hour rain rates up to 0.75 inches will be possible.&nbsp;Finally, it will be possible for 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> storm or two&nbsp;to&nbsp;develop over the far Southeast Plains along a&nbsp;<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> axis, but confidence in this occurring is low. If it does, <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> storm totals up to 1.50 inches may occur, so&nbsp;flooding issues would not be likely.<br>\nPrimetime: 1PM to 10PM<\/p>\n<h4><strong>Southwest Slope, Central Mountains, San Luis Valley, Grand Valley, Northwest Slope &amp; Northern Mountains:<\/strong><\/h4>\n<p>It will be another smoke-filled and dry day for much of the western portion of the state. Near surface smoke may mix out a bit over the lower elevations by this afternoon, but it will likely remain thick over the Northern Mountains. Afternoon highs will reach into the 90Fs for the lower elevations and upper 80Fs for the mountain valleys. A couple storms off the high terrains may spill into the San Luis Valley this evening, but more wind than rainfall is likely as storms advance away from the source of lift. <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> storm totals on the edges of the SLV up to 0.35 inches will be possible. Elsewhere, rainfall is not forecast today.<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Sunday, August 29th, 2021 Issue Time: 10:15AM MDT &mdash; A&nbsp;LOW&nbsp;flood threat has been issued for the Front Range, Urban Corridor and western Palmer Ridge It&rsquo;s a cool and cloudy start to the morning over eastern CO behind yesterday&rsquo;s cold front. Morning temperatures are running around 8-12F cooler than this time yesterday for most [&hellip;]<\/p>","protected":false},"author":8,"featured_media":0,"comment_status":"closed","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\/15796"}],"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=15796"}],"version-history":[{"count":7,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/15796\/revisions"}],"predecessor-version":[{"id":15813,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/15796\/revisions\/15813"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15796"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15796"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15796"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}