{"id":7757,"date":"2018-07-26T08:37:49","date_gmt":"2018-07-26T14:37:49","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=7757"},"modified":"2018-07-27T07:16:13","modified_gmt":"2018-07-27T13:16:13","slug":"ftb-07-26-2018-another-day-another-flood-threat","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=7757","title":{"rendered":"FTB 07-26-2018: Another Day, Another Flood Threat"},"content":{"rendered":"<p>Issue Date: 7\/26\/2018<br>\nIssue Time: 8:42 AM<\/p>\n<p><em>A MODERATE FLOOD THREAT IS FORECAST FOR PORTIONS OF THE SOUTHEAST MOUNTAINS, FRONT RANGE, URBAN CORRIDOR, RATON RIDGE, AND SOUTHEAST PLAINS REGIONS.<\/em><br><em>A LOW FLOOD THREAT IS FORECAST FOR PORTIONS OF THE SOUTHWEST SLOPE, SAN JUAN MOUNTAINS, CENTRAL MOUNTAINS, NORTHERN MOUNTAINS, FRONT RANGE, SOUTHEAST MOUNTAINS, RATON RIDGE, PALMER RIDGE, URBAN CORRIDOR, NORTHEAST PLAINS, AND SOUTHEAST PLAINS.<\/em><\/p>\n<p>The upper-level high that has kept moisture streaming across Colorado the past few days isn&rsquo;t budging much today. This means another day\/night 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> showers and thunderstorms across the state. Over the High Country 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>, <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> values will be less than yesterday as drier air works in from the west\/northwest, and a downtick in storm coverage is expected for those areas. Even so, there will be enough moisture available for moderate rainfall rates, especially over southern mountains. This moisture, combined with antecedent soil moisture and burn scar concerns, are the culprits behind the low flood threat over the Southwest Slope and San Juan Mountains.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2018\/07\/SFC_20180726.png\"><img loading=\"lazy\" class=\" wp-image-7758 aligncenter\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2018\/07\/SFC_20180726.png\" alt=\"\" width=\"561\" height=\"561\"\/><\/a><\/p>\n<p>East 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>, low-level easterly flow will reinforce moisture values, keeping <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> values near\/above 1 inch across much of the area, but especially east of I-25. This will provide the fuel 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> showers and thunderstorms capable of heavy rainfall. Storm motions will be a bit faster today, so that will mitigate the flood threat somewhat, reducing storm residence time over one location. With that said, however, the last few days of heavy rain will exacerbate runoff in areas that have received it, especially in areas of steep and vulnerable terrain. Thus, the issuance of the Moderate Flood Threat for portions of of the Southeast Mountains, Front Range, Urban Corridor, Raton Ridge, and Southeast Plains regions. Eastern plains areas that have received excessive rainfall will also deserve a close eye inside the low flood threat zone. For more information on timing and rain rates, please see the zone-specific forecast discussions below.<\/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, jump below the map.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2018\/07\/MFT_20180726.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-7772 size-full\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2018\/07\/MFT_20180726.png\" alt=\"\" width=\"879\" height=\"497\"\/><\/a><\/p>\n<div><img loading=\"lazy\" class=\"alignright wp-image-135\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/04\/floodthreat_legend2.png\" alt=\"Flood Threat Legend\" width=\"275\" height=\"71\"\/><\/div>\n<h3><strong>Zone-Specific Forecasts<\/strong><\/h3>\n<h4><strong>Front Range, Southeast Mountains, Urban Corridor, Palmer Ridge, Northeast Plains, Southeast Plains, and Raton Ridge:<\/strong><\/h4>\n<p>Another unsettled period 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> showers\/thunderstorms are expected, capable of heavy rainfall. Storm motions will be quicker than previous days, so the flooding threat will be mitigated somewhat. As mentioned above, areas that have received heavy rainfall over the last few days are at the highest relative risk of <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> issues. The wind\/instability profile will be conducive to a few 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>, capable of producing large hail up to 1.75 inches in diameter, strong winds (gusts up to 70 mph), and 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> tornado or two. Maximum rain rates are as follows:<\/p>\n<p>Front Range and Southeast Mountains: 1.0-1.2 inches\/hour<br>\nUrban Corridor: 1.0-1.4 inches\/hour<br>\nNortheast Plains, Southeast Plains, Palmer Ridge, and Raton Ridge: 1.75-2.5 inches\/hour<\/p>\n<p>Timing: Noon &ndash; 9 PM over the Front Range and Southeast Mountains, with a lingering shower\/thunderstorm or two over the Southeast Mountains until 11 PM. 1 PM &ndash; 10 PM for the Urban Corridor and Palmer Ridge, and 1 PM &ndash; Midnight for the Northeast Plains, Southeast Plains, and Raton Ridge. A few showers\/thunderstorms will linger near the CO\/KS border into the early morning hours.<\/p>\n<h4><strong>Northern Mountains, Northwest Slope, Central Mountains, Grand Valley, San Juan Mountains, Southwest Slope, and San Luis Valley:<\/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> showers and thunderstorms are expected again today\/tonight, though a slight downtick in coverage and intensity is expected compared to previous days. As usual, activity will get its start around 11 AM &ndash; Noon, increase in coverage through the late afternoon\/early evening, and diminish as sunset rolls around. Storm motions will be quicker than previous days, to the south-southeast at 15-25 mph, so the flood threat will be mitigated somewhat. Maximum rain rates are as follows:<\/p>\n<p>Northwest Slope and Grand Valley: 0.1-0.3 inches\/hour<br>\nNorthern Mountains and Central Mountains: 0.4-0.8 inches\/hour<br>\nSouthwest Slope, San Juan Mountains, and San Luis Valley: 0.5-0.9 inches\/hour<\/p>\n<p>Timing: 11 AM &ndash; 9 PM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: 7\/26\/2018 Issue Time: 8:42 AM A MODERATE FLOOD THREAT IS FORECAST FOR PORTIONS OF THE SOUTHEAST MOUNTAINS, FRONT RANGE, URBAN CORRIDOR, RATON RIDGE, AND SOUTHEAST PLAINS REGIONS. A LOW FLOOD THREAT IS FORECAST FOR PORTIONS OF THE SOUTHWEST SLOPE, SAN JUAN MOUNTAINS, CENTRAL MOUNTAINS, NORTHERN MOUNTAINS, FRONT RANGE, SOUTHEAST MOUNTAINS, RATON RIDGE, PALMER [&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\/7757"}],"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=7757"}],"version-history":[{"count":3,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/7757\/revisions"}],"predecessor-version":[{"id":7773,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/7757\/revisions\/7773"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7757"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7757"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7757"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}