{"id":9018,"date":"2019-05-17T08:34:28","date_gmt":"2019-05-17T14:34:28","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=9018"},"modified":"2019-05-17T08:34:53","modified_gmt":"2019-05-17T14:34:53","slug":"ftb-05-17-2019-approaching-trough-returns-scattered-storms-and-snow-to-the-forecast","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=9018","title":{"rendered":"FTB 05-17-2019: Approaching Trough Returns Scattered Storms and Snow to the Forecast"},"content":{"rendered":"<p>Issue Date: Friday, May 17th, 2019<br>\nIssue Time: 8:45AM MDT<\/p>\n<p><em>&ndash;Flooding is <strong>NOT<\/strong> expected today<\/em><\/p>\n<p>Currently there is some light to moderate rainfall over western Colorado and with snow being report in Pagosa Springs. These showers are associated with another <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;shortwave&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A disturbance in the mid or upper part of the atmosphere which induces upward motion ahead of it.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>shortwave<\/span> that is rounding itself around the base of 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 some upper air support from the jet. The center of 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> is currently over Nevada and is forecast to move westward today as it becomes an open wave. This should increase rainfall chances from west to east into the afternoon and evening with storms having southwest to northeast movement. For western Colorado, the best chances for measurable rainfall will be 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 Flat Tops. Expect storm activity to continue into mid-afternoon with a break this evening as dry air moves in from Utah (yellow in the image below). However, a surface low is forecast to move into southwest Colorado by early tomorrow morning, so a second set of showers and snow (&gt;8K ft) are likely over SW Colorado to start the day.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/05\/wv_20190517.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-9020\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/05\/wv_20190517.png\" alt=\"\" width=\"650\" height=\"400\"\/><\/a><\/p>\n<p>With southwest winds aloft, moisture over the southeast quadrant of the state will be minimal due to <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;downsloping&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Refers to the winds that blow from higher elevations down towards lower elevations. As air parcels descend, they warm, which often results in rapid warming of areas near the higher terrains. It also promotes lower relative humidity values and stability, which prevents thunderstorm development.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>downsloping<\/span> effects, so not expecting much rainfall over the Southeast Mountains and not much, if any, over the adjacent Southeast Plains and Raton Ridge. The <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;severe thunderstorm&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 thunderstorm<\/span> threat will follow the dry line, which should set up well to the east of Colorado. Some better wrap around moisture exists over the Colorado and Nebraska\/Wyoming border from a surface low over western Nebraska. So as the current set of storms moves to the northeast, best accumulation will be over the northern Front Range, Urban Corridor and Northeast Plains this afternoon and evening. Enhanced convergence along the Cheyenne Ridge will also help boost 24-hour totals along Colorado&rsquo;s northern border. As a cold front starts to drop through the state this evening, coverage of thunderstorms may also increase in this area. Upper dynamics will likely help continue light showers over the higher terrains through midnight. Totals today and tonight are expected to remain under flood threat criteria, so there is no flood threat today.<\/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.<br><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>Front Range, Northern Mountains, Urban Corridor, Palmer Ridge, Northeast Plains:<\/strong><\/h4>\n<p>Increased cloud cover is likely this afternoon as the storms start to form over the Front Range. With northeast movement of the storms and wrap around moisture from the surface low along the northern border, the best chance for measurable rainfall is over the northern Front Range, Urban Corridor and Northeast Plains. The best chance for a <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;severe thunderstorm&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 thunderstorm<\/span> is over northern Weld and Logan County, although better dynamics will be located in the panhandle of Nebraska. Max 1-hr rain rates up to 0.5 inches will be possible (east) with 24-hr totals just over 0.5 inches (west). Flooding is not forecast.<\/p>\n<p>Primetime: 12PM to Midnight<\/p>\n<h4><strong>Northwest Slope, Grand Valley, Southwest Slope, Central Mountains, San Juan Mountains, San Luis Valley:<\/strong><\/h4>\n<p>Expect ongoing showers through early this afternoon until the dry slot arrives. This should bring a break in precipitation until the next wave moves into southwest Colorado early tomorrow morning. This wave will bring snow to higher elevations (&gt;8K ft) with rain at lower elevations. 24-hour totals up to 0.5 inches are possible over the Central and San Juan Mountains, with the highest accumulations 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 Flat Tops where 24-hour totals could reach 0.8 inches. Flooding is not forecast today.<\/p>\n<p>Primetime: Ongoing to 8AM<\/p>\n<h4><strong>Raton Ridge, Southeast Mountains, Southeast Plains:<\/strong><\/h4>\n<p>Not too much moisture over the area with the southwest winds aloft. While some cloud cover and light sprinkles may form over the Southeast Mountains, they should evaporate quickly over the adjacent plains. Some strong surface winds are possible today, and with the low relative humidity, fire danger is slightly elevated. With the spring green up, large scale fire growth should be limited. Gusts up to 35 mph are forecast over the Southeast Plains and Raton Ridge, with some higher gusts over the Southeast Mountains. Best chance for precipitation is over the western Southeast Mountains, where most of the precipitation will fall as snow overnight into tomorrow morning. Flooding is not forecast.<\/p>\n<p>Primetime: 2PM to 8AM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Friday, May 17th, 2019 Issue Time: 8:45AM MDT &ndash;Flooding is NOT expected today Currently there is some light to moderate rainfall over western Colorado and with snow being report in Pagosa Springs. These showers are associated with another <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;shortwave&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A disturbance in the mid or upper part of the atmosphere which induces upward motion ahead of it.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>shortwave<\/span> that is rounding itself around the base of 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 some upper air [&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\/9018"}],"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=9018"}],"version-history":[{"count":2,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/9018\/revisions"}],"predecessor-version":[{"id":9022,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/9018\/revisions\/9022"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=9018"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=9018"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=9018"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}