{"id":1655,"date":"2015-08-15T10:16:34","date_gmt":"2015-08-15T16:16:34","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=1655"},"modified":"2015-08-16T06:53:04","modified_gmt":"2015-08-16T12:53:04","slug":"ftb-08-15-2015-moisture-still-in-place-under-upper-level-ridge","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=1655","title":{"rendered":"FTB 08-15-2015: Moisture Still in Place Under Upper-Level Ridge"},"content":{"rendered":"<p>Issue Date: 8\/15\/2015<br>\nIssue Time: 10:05 AM<\/p>\n<p><em>A LOW FLOOD THREAT IS FORECAST FOR PORTIONS OF THE PALMER RIDGE, NORTHEAST PLAINS, SOUTHEAST PLAINS, SAN JUAN MOUNTAINS, FRONT RANGE, NORTHERN MOUNTAINS, AND CENTRAL MOUNTAINS.<\/em><\/p>\n<p>Another day of <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 is on tap today. Storms will be more <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;numerous&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;40-60% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>numerous<\/span> over the higher terrain than lower elevations, but regardless of location, all stronger storms will hold the threat of producing locally heavy rainfall. Underneath the upper-level ridge, the large-scale environment is basically neutral for today, but daytime heating will combine with residual moisture to produce thunderstorms, much like yesterday. Also like yesterday, weak steering winds aloft will lead to relatively slow storm motions, providing the opportunity for storms to rain over one location for an extended period of time.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/08\/08152015_IPW.png\"><img loading=\"lazy\" class=\"  wp-image-1654 aligncenter\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/08\/08152015_IPW.png\" alt=\"08152015_IPW\" width=\"534\" height=\"229\"\/><\/a><\/p>\n<p>For the lower elevations of eastern Colorado, <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow boundaries&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A surface boundary formed by the horizontal spreading of thunderstorm-cooled air. Outflow boundaries may intersect with each other or with other features (fronts, dry line, low-level jet) and initiate new convection. Brief strong winds are possible with outflow boundaries, and they can also persist for more than 24 hours.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>outflow boundaries<\/span> from mountain <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;convection&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Refers to vertical atmospheric motion driven by buoyancy, i.e., warm air is less dense than cool air, and therefore rises. One of the primary drivers of thunderstorm development, especially during monsoon season.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>convection<\/span> will be the main source of forcing for thunderstorms, with a few being the result of strong solar heating. Either way, ample moisture will make heavy rain a threat from any thunderstorm. Other threats include strong winds and lightning, with one or two thunderstorms becoming marginally severe producing wind gusts greater than 55 mph. It looks like the Urban Corridor may be spared the heavy rain threat today, as drier low-level air is in place along the interface with the mountains 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> winds. If the westerly component remains in place through the afternoon, light-to-moderate rain and gusty winds will be all that thunderstorms can muster over the region. For more information on rain rates and timing, please see the zone-specific 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<div style=\"position: relative;\"><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/08\/08152015_LFT.png\"><img loading=\"lazy\" class=\"alignnone size-full wp-image-1657\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/08\/08152015_LFT.png\" alt=\"08152015_LFT\" width=\"886\" height=\"497\"\/><\/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>Urban Corridor, Northeast Plains, Raton Ridge, Palmer 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> thunderstorms are expected, with the best coverage over the Palmer Ridge and Southeast Plains regions. Maximum rain rates will vary, so here is the breakdown:<\/p>\n<p>Urban Corridor: 0.4-0.8 inches\/hour<br>\nPalmer Ridge, Northeast Plains, and Southeast Plains: 1.5-2.5 inches\/hour<br>\nRaton Ridge: 0.8-1.2 inches\/hour<\/p>\n<p>Timing: 1 PM &ndash; 10 PM, with a couple thunderstorms lingering until midnight, or just after, across the Plains.<\/p>\n<h4><strong>Northern Mountains, Front Range, Central Mountains, San Luis Valley, Northwest Slope, San Juan Mountains, Southwest Slope, Grand Valley, and 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> thunderstorms expected over the higher terrain, with more <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> coverage over the lower valleys. The best relative coverage will be over the San Juan Mountains, Central Mountains, Northern Mountains, and Front Range. Maximum rain rates vary:<\/p>\n<p>Northern Mountains, San Juan Mountains, Front Range, and Central Mountains: 0.8-1.4 inches\/hour<br>\nSoutheast Mountains and San Luis Valley: 0.4-0.8 inches\/hour<br>\nSouthwest Slope, Northwest Slope, and Grand Valley: 0.3-0.6 inches\/hour<\/p>\n<p>Timing: Noon &ndash; 10 PM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: 8\/15\/2015 Issue Time: 10:05 AM A LOW FLOOD THREAT IS FORECAST FOR PORTIONS OF THE PALMER RIDGE, NORTHEAST PLAINS, SOUTHEAST PLAINS, SAN JUAN MOUNTAINS, FRONT RANGE, NORTHERN MOUNTAINS, AND CENTRAL MOUNTAINS. Another day of <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 is on tap today. Storms will be more <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;numerous&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;40-60% areal coverage&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>numerous<\/span> over the higher terrain than lower [&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\/1655"}],"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=1655"}],"version-history":[{"count":2,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/1655\/revisions"}],"predecessor-version":[{"id":1660,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/1655\/revisions\/1660"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1655"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1655"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1655"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}