{"id":10093,"date":"2019-07-31T10:22:12","date_gmt":"2019-07-31T16:22:12","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=10093"},"modified":"2019-10-08T11:13:56","modified_gmt":"2019-10-08T17:13:56","slug":"ftb-07-31-2019-persistent-weak-thunderstorms-west-of-the-continental-divide","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=10093","title":{"rendered":"FTB 07-31-2019: Persistent Weak Thunderstorms West of the Continental Divide"},"content":{"rendered":"<p>Issue Date: Wednesday, July 31, 2019<br>\nIssue Time: 10:35AM MDT<\/p>\n<p><em>&mdash; Flooding is&nbsp;<strong>NOT&nbsp;<\/strong>expected today<\/em><\/p>\n<p>The subtropical high pressure that has been controlling our weather this past week will continue to build and move it&rsquo;s way east throughout the day today. The mid-level water vapor imagery below shows high levels of moisture to the west of Colorado, which will move it&rsquo;s way slowly over the area the next few days. This morning&rsquo;s sounding over Grand Junction shows an increase in moisture from yesterday, measuring 0.98 inches of <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>. Dewpoints over the western slope are also high this morning, measuring in the 40&deg;Fs and 50&deg;Fs over the lower terrain.&nbsp; Midlevel winds will increase throughout the day, with a weak low level jet developing overnight over the northwest corner of the state. Persistent thunderstorms over the area provide the highest chances 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> moderate rainfall over 2-3 hours. Storms are forecast to the 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> throughout the afternoon and into the early evening, with storms over the northwest quadrant extending into the early morning.<\/p>\n<p>To the 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> the setup will be similar to yesterday, but moisture levels will increase throughout the day. <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> was measured at 0.69 inches over Denver this morning, but is forecast to increase up to 1.7 inches over the Northeast Plains. Low pressure over the eastern plains will aid downslope flow to create a <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;dryline&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A low-level, small-scale boundary that separates dry air from moist air. Storms develop along it because the dry air (behind the boundary) is less dense than the moisture-rich air (ahead of the boundary). Typically, it advances eastward during the afternoon and retreats westward at night.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>dryline<\/span> (orange line below) over the eastern plains this morning. The low is forecast to remain and deepen, which will pull surface moisture back to the west throughout the forecast period. Upslope flow over the foothills and the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;dryline&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A low-level, small-scale boundary that separates dry air from moist air. Storms develop along it because the dry air (behind the boundary) is less dense than the moisture-rich air (ahead of the boundary). Typically, it advances eastward during the afternoon and retreats westward at night.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>dryline<\/span> will provide forcing for thunderstorms this afternoon. Storms are forecast to begin over the Raton Ridge and Southeast Plains by 12PM, with storms over the Palmer Ridge and Northeast plains this afternoon and into the night.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/07\/FTB_20190731_WV.jpg\"><img loading=\"lazy\" class=\"aligncenter wp-image-10094\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/07\/FTB_20190731_WV.jpg\" alt=\"\" width=\"750\" height=\"520\"\/><\/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. For Zone-Specific forecasts, scroll below the map.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/05\/FTB_No_Flood_Threat_2019.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-8803\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/05\/FTB_No_Flood_Threat_2019.png\" alt=\"\" width=\"880\" height=\"580\"\/><\/a><\/p>\n<h3><strong>Zone-Specific Forecasts:<\/strong><\/h3>\n<h4><strong>San Luis Valley, San Juan Mountains, Southwest Slope, Grand Valley, Northwest Slope, Central Mountains, Northern Mountains:<\/strong><\/h4>\n<p><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> max 3-hour rainfall rates up to 0.75 inches will be possible over the northern regions, with max 24-hour totals up to 1.5 inches. &nbsp;Expect the highest daily totals over the Northwest Slope and Northern Mountains, with persistent storms throughout the duration of the forecast period. Continual moisture <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;advection&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The process of transport of an atmospheric property, typically temperature or moisture in our FTB discussions, by the wind. &amp;quot;Strong&rdquo; or &amp;quot;weak&rdquo; advection refers to the rate of change of the advected property&amp;#039;s value at a given point.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>advection<\/span> and steering winds between 10 and 15 mph will bring multiple rounds of storms over the area.&nbsp; Rain will favor the high terrain over the Southwest Slope and San Juan Mountains, 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> max 3-hour rainfall rates up to 0.5 inches.&nbsp; Storms will begin by noon over the southern regions, extending through the central and northern regions by 2PM.&nbsp; Rainfall is forecast over all elevations over the central and northern regions due to high levels of surface moisture. &nbsp;The San Luis Valley is forecast to receive little to no precipitation. &nbsp;Wind gusts up to 50 mph are expected over the lower elevations once again today.<\/p>\n<p>Primetime: 12PM to 5AM<\/p>\n<h4><strong>Front Range, Urban Corridor, Northeast Plains, Palmer Ridge, Southeast Plains, Southeast Mountains, Raton Ridge<\/strong><\/h4>\n<p>Storms today are most likely along 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 areas over and near the Cheyenne Ridge, Palmer Ridge and Raton Ridge.&nbsp; Most storms are forecast to remain <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;capped&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\"}]'>capped<\/span> over the eastern plains, but chances 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> severe weather are still possible.&nbsp; Max 1-hour rainfall rates of 1.25 inches are possible, although unlikely, over the Northeast Plains, southern Urban Corridor and Palmer Ridge. Over the high terrain, max 1-hour rainfall rates up to 0.3 inches are possible.&nbsp; Storms are forecast to begin over the Raton Ridge and Southeast Mountains by noon, with storms over the Front Range by 2PM.&nbsp; Late afternoon thunderstorms may form off of the Palmer Ridge and move over the Northeast Plains early tonight.&nbsp; Flooding is not forecast over the area.<\/p>\n<p>Primetime: 12PM to 2AM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Wednesday, July 31, 2019 Issue Time: 10:35AM MDT &mdash; Flooding is&nbsp;NOT&nbsp;expected today The subtropical high pressure that has been controlling our weather this past week will continue to build and move it&rsquo;s way east throughout the day today. The mid-level water vapor imagery below shows high levels of moisture to the west of [&hellip;]<\/p>","protected":false},"author":1,"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\/10093"}],"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\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10093"}],"version-history":[{"count":2,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/10093\/revisions"}],"predecessor-version":[{"id":11052,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/10093\/revisions\/11052"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10093"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10093"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10093"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}