{"id":15011,"date":"2021-07-18T09:25:01","date_gmt":"2021-07-18T15:25:01","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=15011"},"modified":"2021-07-19T08:12:30","modified_gmt":"2021-07-19T14:12:30","slug":"ftb-07-18-2021-low-flood-threat-persists-for-san-juans-isolated-strongsevere-storm-out-east","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=15011","title":{"rendered":"FTB 07-18-2021: Low Flood Threat Persists For San Juans; Isolated Strong\/Severe Storm Out East"},"content":{"rendered":"<p>Issue Date: Sunday, July 18th, 2021<br>\nIssue Time: 9:20AM MDT<\/p>\n<p><em>&mdash; A <strong>LOW<\/strong> flood threat has been posted for parts of the San Juan Mountains<\/em><\/p>\n<p>As shown in the water vapor image, below, an upper-level ridge has strengthened significantly over the past 24 hours and is now positioned over western Colorado. Plenty of moisture is still &ldquo;stuck&rdquo; underneath the ridge with morning radiosonde <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> coming in at 0.91 inches at Grand Junction and 0.82 inches at Denver. However, a notable area of subsidence and upper-level drying was noted along the WY\/NE border today so <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> should slightly decrease through the day over the eastern half of Colorado. On the other hand, <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 Albuquerque came in at an impressive 1.21 inches, with a moist adiabatic type sounding profile indicating very efficient rain rates are possible. A simple interpolation between Albuquerque and Grand Junction implies the southwest part of Colorado currently has <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 around 1.0 inch, which is significantly above normal for this time of year. Despite the warm mid-level temperatures we expect <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 thunderstorms again for the southern high terrain. However, today, the LOW flood threat will be limited to just the climatologically favored San Juan Mountains where E\/ENE steering flows of 10-15mph along with instability up to 800 J\/kg will support heavy rainfall cores. Elsewhere, lower rainfall coverage is expected. However, <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> 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> will once again be possible over the Northeast and Southeast Plains, though steering flow of 25mph+ will limit point rainfall to below flood threat thresholds.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/wv_markup-6.png\"><img loading=\"lazy\" class=\" wp-image-15018 aligncenter\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/wv_markup-6.png\" alt=\"\" width=\"685\" height=\"471\"\/><\/a><\/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\/07\/FTB_20210718_snap.png\"><img loading=\"lazy\" class=\"size-full wp-image-15029 aligncenter\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210718_snap.png\" alt=\"\" width=\"897\" height=\"607\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210718_snap.png 897w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210718_snap-300x203.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/07\/FTB_20210718_snap-768x520.png 768w\" sizes=\"(max-width: 897px) 100vw, 897px\"\/><\/a><\/p>\n<h3><strong>Zone-Specific Forecasts:<\/strong><\/h3>\n<h4><strong>San Juan Mountains, Southwest Slope, San Luis Valley, Southeast Mountains, and Raton Ridge:<\/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> 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 thunderstorms especially over the higher terrain of the San Juan Mountains where max 30-min rainfall up to 0.7 inches and max 1-hour rainfall up to 1.2 inches is expected. A LOW flood threat has been posted for the San Juans for <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> <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>, debris slides and mud flows. Elsewhere, <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;widely scattered&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;10-25% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>widely scattered<\/span> storm coverage is expected with max 1-hour rainfall up to 0.8 inches.<\/p>\n<p>Primetime: 12PM through 10PM<\/p>\n<h4><strong>Northeast Plains, Palmer Ridge and Southeast Plains:<\/strong><\/h4>\n<p>Hot 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;widely scattered&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;10-25% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>widely scattered<\/span> showers and thunderstorms possible this afternoon and evening. Max 1-hour rainfall up to 0.9 inches (west) and 1.5 inches (east), which is just below flood threat thresholds. However, nuisance street\/field ponding is possible under the strongest cells. Severe weather, in the form of large hail and damaging winds, will also be possible especially in eastern areas along the KS and NE borders.<\/p>\n<p>Primetime: 2PM through 11PM<\/p>\n<h4><strong>Northwest Slope, Grand Valley, Northern Mountains, Central Mountains, Front Range and Urban Corridor:<\/strong><\/h4>\n<p>Hot with 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> shower or storm possible especially over the higher terrain. Max 1-hour rainfall up to 0.6 inches possible. Flooding is NOT expected today.<\/p>\n<p>Primetime: 1PM through 9PM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Sunday, July 18th, 2021 Issue Time: 9:20AM MDT &mdash; A LOW flood threat has been posted for parts of the San Juan Mountains As shown in the water vapor image, below, an upper-level ridge has strengthened significantly over the past 24 hours and is now positioned over western Colorado. Plenty of moisture is [&hellip;]<\/p>","protected":false},"author":4,"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\/15011"}],"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=15011"}],"version-history":[{"count":3,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/15011\/revisions"}],"predecessor-version":[{"id":15030,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/15011\/revisions\/15030"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15011"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15011"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15011"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}