{"id":439,"date":"2015-05-16T09:37:17","date_gmt":"2015-05-16T15:37:17","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=439"},"modified":"2015-05-17T06:14:16","modified_gmt":"2015-05-17T12:14:16","slug":"ftb-05-16-2015-upper-level-low-continues-to-slide-east","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=439","title":{"rendered":"FTB 05-16-2015: Upper-Level Low Continues to Slide East"},"content":{"rendered":"<p>Issue Date: 5\/16\/2015<br>\nIssue Time: 9:30 AM<\/p>\n<p><em>NO FLOOD THREAT IS FORECAST FOR TODAY. HOWEVER, STREET PONDING IS POSSIBLE ACROSS THE URBAN CORRIDOR BETWEEN I-70 AND JUST SOUTH OF CASTLE ROCK DUE TO WEAK STEERING WINDS IN THIS OUTLINED AREA.<\/em><\/p>\n<p>The upper-level low that we discussed yesterday is on the move again today, moving eastward from its current position over Utah. This will allow for two &ldquo;waves&rdquo; of precipitation today; the first as showers and thunderstorms (with snow above 9000 feet), the second will be overnight snow showers over the mountains. These two distinct &ldquo;waves&rdquo; show up well in the water vapor imagery, with the red arrow marking today&rsquo;s disturbance, and the yellow arrow marking tonight&rsquo;s disturbance.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/05\/05162015_WV.png\"><img loading=\"lazy\" class=\"  wp-image-438 aligncenter\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/05\/05162015_WV.png\" alt=\"05162015_WV\" width=\"744\" height=\"601\"\/><\/a><\/p>\n<p><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 are on the low-side of normal for this time of year, so expect most rainfall to be of the light-to-moderate variety, with the best chance of heavy rain near the CO\/KS border. For these reasons, no flood threat is being issued today. With that said, as outlined in the header text above, street ponding is possible across the Urban Corridor between I-70 and just south of Castle Rock due to weak steering winds\/storm motion. Another 3-6 inches of snow accumulations are likely above 9000 feet across the San Juan Mountains and Central Mountains, with lighter accumulations for other mountains through the overnight hours.<\/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<div style=\"position: relative;\"><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/05\/NoFloodThreat.png\"><img loading=\"lazy\" class=\"alignnone size-full wp-image-442\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/05\/NoFloodThreat.png\" alt=\"NoFloodThreat\" width=\"882\" height=\"496\"\/><\/a><\/div>\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><\/h3>\n<h3><strong>Zone-Specific Forecasts<\/strong><\/h3>\n<h4><strong>Front Range, Urban Corridor, Palmer Ridge, Northeast Plains, Raton Ridge, and Southeast Plains:<\/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>-to-<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, beginning between 11 AM and Noon, and diminishing after sunset. A few <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> thunderstorms will be ongoing across the Northeast Plains until Midnight before exiting the state to the east.<\/p>\n<p>Maximum rain rates will be in the 0.7-1.0 inch\/hour range for much of the area, with stronger storms near the CO\/KS border producing maximum rain rates of 1.0-1.4 inches\/hour. Douglas, Elbert, southern Denver, and Arapahoe Counties will be a focus region for potential of stronger thunderstorm development this afternoon, which will hold the ability to produce maximum rain rates of 0.9-1.4 inches\/hour. However, the realized rain rates will likely be closer to 0.75-1.0 inches\/hour. This is the reason for the highlight of street flooding mentioned in the discussion above, but no flood threat being issued. Likely rain rates will be below <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;flash flood&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 flood<\/span> thresholds, but a slow storm motion can cause drainage issues, especially in low-lying intersections and normal trouble spots.<\/p>\n<h4><strong>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, beginning 10 AM-Noon, and diminishing by sunset as mid-level flow becomes more northwesterly and daytime heating ends. Maximum rain rates will be in the 0.2-0.45 inches\/hour range.<\/p>\n<h4><strong>Northern Mountains, Central Mountains, San Juan Mountains, Northwest Slope, Southwest Slope, Grand Valley, and San Luis Valley:<\/strong><\/h4>\n<p>Much like yesterday, locations above 9000 feet can 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> snow showers today, with lower elevations experiencing <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 this today and this evening (Now &ndash; 9 PM). Central and Southern regions will be favored for the most coverage of showers and storms during this time period. Maximum rain rates will be 0.2-0.4 inches\/hour.<\/p>\n<p>Overnight, as the second disturbance moves across the area, northerly flow will bring <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;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> snow showers to higher elevations thanks to orographic lift. Central and Northern regions will be favored for this overnight activity (10 PM &ndash; 8 AM).<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: 5\/16\/2015 Issue Time: 9:30 AM NO FLOOD THREAT IS FORECAST FOR TODAY. HOWEVER, STREET PONDING IS POSSIBLE ACROSS THE URBAN CORRIDOR BETWEEN I-70 AND JUST SOUTH OF CASTLE ROCK DUE TO WEAK STEERING WINDS IN THIS OUTLINED AREA. The upper-level low that we discussed yesterday is on the move again today, moving eastward [&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\/439"}],"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=439"}],"version-history":[{"count":3,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/439\/revisions"}],"predecessor-version":[{"id":445,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/439\/revisions\/445"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=439"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=439"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=439"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}