{"id":6873,"date":"2018-05-18T10:15:39","date_gmt":"2018-05-18T16:15:39","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=6873"},"modified":"2018-05-19T05:26:46","modified_gmt":"2018-05-19T11:26:46","slug":"ftb-05-18-2018-overnight-threat-for-heavy-rainfall","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=6873","title":{"rendered":"FTB 05-18-2018: Overnight Threat for Heavy Rainfall"},"content":{"rendered":"<p>Issue Date: Friday, May 18, 2018<br>\nIssue Time: 10:15AM MDT<\/p>\n<p><em>&mdash; <strong>MODERATE\/LOW <\/strong>flood threat for Front Range, Urban Corridor and Northeast Plains<\/em><\/p>\n<p><em>&mdash;&nbsp;<strong>LOW<\/strong>&nbsp;flood threat for Southeast Plains and Palmer Ridge<\/em><\/p>\n<p>Quite a change to the weather pattern to start this weekend. As previously discussed in the FTO, the continuous low pressure that has been spinning over Nevada will finally begin to breakdown and eject over Wyoming this afternoon. Currently, the low is located in NW Utah and marked on the water vapor imagery below. This afternoon a lee cyclone is expected to form over the Southeast Plains, which will help pull higher moisture into the state to its north. It will also help trigger thunderstorm development over the Southeast Mountains and Raton Ridge. Strong convergence occurs on the east side of the lee cyclone, so storms that track into this area will be the focus for severe weather. Threats include large hail, gusty winds and a possible tornado. 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 main focus will be increased shower potential and cloud cover over the higher elevations.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2018\/05\/wv_20180518.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-6874\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2018\/05\/wv_20180518.png\" alt=\"\" width=\"600\" height=\"358\"\/><\/a><\/p>\n<p>Over NE Colorado this morning, heavy cloud cover is present. Expecting cloud cover to modestly break up throughout the day, but increased lift associated with 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 high moisture will likely keep the cloud deck somewhat intact over the Front Range. As 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> moves through this afternoon, it will help trigger <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;widespread&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;greater than 60% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>widespread<\/span> thunderstorms along the Front Range, Northern Mountains and Palmer Ridge. While these thunderstorms are expected to cluster into a <span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;MCS&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;(Stands for: Mesoscale Convective System) A complex of thunderstorms that produces a large, contiguous area of precipitation on the order of 100 km or more in the horizontal scale and normally persist for several hours or more.&lt;\/div&gt;\"  data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>MCS<\/span> over the plains, a select few could become severe over areas with higher instability. The main threat with the stronger storms will be large hail, gusty winds and heavy rainfall. Rainfall is expected to continue overnight in the northern Urban Corridor and Northeast Plains. Over the higher elevations in the north, heavy snowfall is possible. For more details, please see the regional forecasts 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. For Zone-Specific forecasts, scroll below the map.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2018\/05\/MFT_20180518.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-6881\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2018\/05\/MFT_20180518.png\" alt=\"\" width=\"880\" height=\"496\"\/><\/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>Palmer Ridge, Front Range, Urban Corridor, Northeast Plains, Southeast Plains, Raton Ridge, Southeast Mountains:<\/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 today and tonight. A few storms may become severe further east. Over the Northeast Plains, localized totals up to 3.25 inches are possible by tomorrow morning. Flood threats over the Northeast Plains and Urban Corridor include small stream flooding, street flooding and field ponding. Over the northern high terrain small stream flooding and debris slides are possible. Burn scars in the area should be monitored closely this afternoon. A Moderate flood threat has been issued.<\/p>\n<p>Maximum rain rates:<br>\nNortheast Plains: 1.75 inches\/hour<br>\nUrban Corridor, Palmer Ridge, Raton Ridge and Southeast Plains: 1.25 inches\/hour<br>\nFront Range and Southeast Mountains: 0.85 inches\/hour<\/p>\n<p>Primetime: 12PM to 11 AM<\/p>\n<h4><strong>Northwest Slope, Grand Valley, Southwest Slope, Northern Mountains, San Luis Valley, San Juan Mountains, Central Mountains:<\/strong><\/h4>\n<p>More cloud cover and <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 over the higher terrains are expected today. Moisture for showers,&nbsp;possibly accompanied by a&nbsp;role of thunder, is best over the Northern and Central Mountains. However, gusty winds are more likely than&nbsp;measurable rainfall. Max 1-hour rain rates up to 0.1 inches. Flooding is not expected today.<\/p>\n<p>Primetime: 1PM to 9PM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Friday, May 18, 2018 Issue Time: 10:15AM MDT &mdash; MODERATE\/LOW flood threat for Front Range, Urban Corridor and Northeast Plains &mdash;&nbsp;LOW&nbsp;flood threat for Southeast Plains and Palmer Ridge Quite a change to the weather pattern to start this weekend. As previously discussed in the FTO, the continuous low pressure that has been spinning [&hellip;]<\/p>","protected":false},"author":8,"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\/6873"}],"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=6873"}],"version-history":[{"count":2,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/6873\/revisions"}],"predecessor-version":[{"id":6882,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/6873\/revisions\/6882"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6873"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6873"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6873"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}