{"id":1050,"date":"2015-06-29T10:31:42","date_gmt":"2015-06-29T16:31:42","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=1050"},"modified":"2015-06-30T09:55:18","modified_gmt":"2015-06-30T15:55:18","slug":"ftb-06-29-2015-another-day-of-isolated-to-scattered-showers-and-thunderstorms","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=1050","title":{"rendered":"FTB 06-29-2015: Another Day of Isolated-to-Scattered Showers and Thunderstorms"},"content":{"rendered":"<p>Issue Date: 6\/29\/2015<br>\nIssue Time: 10:22 AM<\/p>\n<p><em>A LOW FLOOD THREAT HAS BEEN ISSUED FOR PORTIONS OF THE FRONT RANGE, URBAN CORRIDOR, CENTRAL MOUNTAINS AND SAN JUAN MOUNTAINS.<\/em><\/p>\n<p>The forecast has been fairly consistent over the last few days as the upper-level ridge continues to be anchored across the Western US, centered over Utah. This is has left Colorado under the influence of northerly flow aloft, creating mean storm motions from north to south, and leaving the bulk of shower\/thunderstorm activity over the High Country. Moisture has not only remained, but maintained, near-average to above-average, and today is no different; <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> is above average for this date, running between 0.75 and 1.0 inches at the normal four reporting stations shown in the graph below (Boulder &ndash; blue, Grand Junction &ndash; green, Pueblo &ndash; pink, and Shriever AFB &ndash; red).<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/06\/IPW_06292015.png\"><img loading=\"lazy\" class=\"  wp-image-1051 aligncenter\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/06\/IPW_06292015.png\" alt=\"IPW_06292015\" width=\"511\" height=\"219\"\/><\/a><\/p>\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 across the High Country, following the diurnal pattern of beginning around lunchtime, maximizing coverage during the late afternoon and early evening, before diminishing just after sunset as daytime heating ends and radiational cooling begins. Just as yesterday, 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 are expected over the adjacent lower elevations of the Urban Corridor, Palmer Ridge, Northeast Plains, and Southeast Plains, with the relative best chances occurring near the preferred terrain of the Front Range, Palmer Ridge, and Southeast Mountains. Adding an additional complexity to today&rsquo;s forecast is a weak surface boundary that will scrape across the far Northeast and Southeast Plains, providing support for <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> afternoon\/evening thunderstorms. Primary concerns with most thunderstorm activity will be gusty <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A cool pool of air that results when a thunderstorm downdraft reaches the surface and spreads horizontally.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>outflow<\/span> winds, lightning, small hail, and brief moderate-to-heavy rain. For more specifics regarding rain rates, check out the zone-specific 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 (hover over threat areas for more details). For Zone-Specific forecasts, jump below the map.<br><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/06\/FTB_snapshot_20150629.png\"><img loading=\"lazy\" class=\"aligncenter  wp-image-1072\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/06\/FTB_snapshot_20150629.png\" alt=\"FTB_snapshot_20150629\" width=\"833\" height=\"531\"\/><\/a><\/p>\n<h3><\/h3>\n<h3><strong>Zone-Specific Forecasts<\/strong><\/h3>\n<h4><strong>Urban Corridor, Palmer Ridge, Southeast Plains, and Northeast Plains, and Raton Ridge:<\/strong><\/h4>\n<p>Mostly sunny and hot will be the main story today, as high temperatures remain in the mid-80s to low-90s across the regions. <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 are expected this afternoon and evening, thanks to the conditions outlined above. The main threats will be lightning, strong <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A cool pool of air that results when a thunderstorm downdraft reaches the surface and spreads horizontally.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>outflow<\/span> winds, hail (up to 1.5 inches in diameter), and brief moderate-to-heavy rain. Rain rates will typically be 0.4-0.8 inches\/hour, but a couple strong\/marginally severe storms could produce rain up to 0.9-1.3 inches\/hour.<\/p>\n<p>Timing: Noon &ndash; 10 PM<\/p>\n<h4><strong>Front Range and Northern Mountains:<\/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> showers and thunderstorms expected, with the main threats being gusty <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A cool pool of air that results when a thunderstorm downdraft reaches the surface and spreads horizontally.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>outflow<\/span> winds, small hail, and lightning. The Front Range south of I-70 will hold the best chance for bouts with brief heavy rain, with rain rates in the 0.5-0.8 inches\/hour range. With most of the moisture confined to the mid-levels, and relatively shallow low-level moisture, dry air beneath the cloud base will eat away at precipitation before reaching the surface. However, an <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow boundary&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 boundary<\/span> from another storm interacting with a thunderstorm over the southern Front Range could push maximum rain rates to 0.8-1.2 inches\/hour. This is a relatively low probability, but cannot be ruled out, thus the inclusion in the outlined Low Flood Threat area.<\/p>\n<p>Timing: Noon &ndash; 8 PM<\/p>\n<h4><strong>Northwest Slope and Grand Valley:<\/strong><\/h4>\n<p>Mostly sunny and hot will be the main story of the day, with 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> thunderstorm or two possible over the higher terrain near the Central Mountain and Southwest Slope regions. The main threats from any <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 lightning and gusty <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A cool pool of air that results when a thunderstorm downdraft reaches the surface and spreads horizontally.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>outflow<\/span> winds, as rain rates will stay below 0.25 inches\/hour.<\/p>\n<p>Timing: Noon &ndash; 6 PM<\/p>\n<h4><strong>Central Mountains, Southeast Mountains, San Luis Valley, Southwest Slope, and San Juan 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 expected, mainly over the higher terrain. With mean storm motions from north to south, activity will move over lower elevations and valleys with time. Rain rates will typically be in the 0.3-0.6 inches\/hour range, but brief heavy rain over the San Juan Mountains (0.9-1.3 inches\/hour) and Central Mountains (0.8-1.2 inches\/hour) is possible. The main threats from thunderstorms will be gusty <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;A cool pool of air that results when a thunderstorm downdraft reaches the surface and spreads horizontally.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>outflow<\/span> winds, lightning, and small hail. There have been <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> reported injuries in the mountains from lightning over the last few weeks, so please be aware of changing weather conditions and seek shelter, if necessary.<\/p>\n<p>Timing: 11 AM &ndash; 9 PM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: 6\/29\/2015 Issue Time: 10:22 AM A LOW FLOOD THREAT HAS BEEN ISSUED FOR PORTIONS OF THE FRONT RANGE, URBAN CORRIDOR, CENTRAL MOUNTAINS AND SAN JUAN MOUNTAINS. The forecast has been fairly consistent over the last few days as the upper-level ridge continues to be anchored across the Western US, centered over Utah. This [&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\/1050"}],"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=1050"}],"version-history":[{"count":3,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/1050\/revisions"}],"predecessor-version":[{"id":1073,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/1050\/revisions\/1073"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1050"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1050"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1050"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}