{"id":4920,"date":"2017-06-15T14:45:51","date_gmt":"2017-06-15T20:45:51","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=4920"},"modified":"2017-06-19T09:27:40","modified_gmt":"2017-06-19T15:27:40","slug":"fto-06-15-2017-continued-drier-than-normal-pattern-short-term-drought-concerns-out-west","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=4920","title":{"rendered":"FTO 06-15-2017: Continued Drier Than Normal Pattern, Short-term Drought Concerns Out West"},"content":{"rendered":"<p>Issue Date: Thursday, June 15th, 2017<br>\nIssue Time: 2:50PM MDT<br>\nValid Dates: 6\/16 &ndash; 6\/30<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/06\/threat_timeline-4.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-4922\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/06\/threat_timeline-4.png\" alt=\"\" width=\"880\" height=\"97\"\/><\/a><\/p>\n<p>This afternoon&rsquo;s North Pacific Ocean water vapor imagery, below, continues to show a zonally oriented, strong <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;jet stream&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Relatively strong winds concentrated within a narrow stream in the atmosphere. General weather patterns are related closely to the position, strength and orientation of the jet stream.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>jet stream<\/span> extending nearly to the North American coastline. While there has been a lot of variability in weather across the northwest U.S., our weather in Colorado has been quieter, in large part due to the substantial amount of dry air that has been entrained from the southwest. This large reservoir of dry air is easily seen west of the Gulf of California and will continue to affect our state over the next 7-10 day period. However, areas 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> will be disproportionately impacted, because eastern areas will see episodes of moister air drawn in from the Gulf of Mexico.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/06\/wv_markup-12.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-4923\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/06\/wv_markup-12.png\" alt=\"\" width=\"640\" height=\"373\"\/><\/a><\/p>\n<p>While we have identified two precipitation events for this 15-day Flood Threat Outlook, it is becoming more likely that hot and dry weather will continue to dominate headlines, especially for western Colorado. A look at the <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> (<span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;PW&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;(Stands for: Precipitable Water) 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\"}]'>PW<\/span>) plumes from the GFS ensembles highlights this story. Note at Denver, <span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;PW&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;(Stands for: Precipitable Water) 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\"}]'>PW<\/span> is expected to briefly peak just under 1 inch and then retreat back to its seasonal normal range. On the contrary, at Grand Junction, after a brief spike to 0.7 inches (though this will be dominated by mid-level moisture that will carry little odds of precipitation), values retreat to below seasonal normal level through 6\/23, and even thereafter. In all, due to the combination of above normal temperatures, below normal precipitation over the past 2 weeks and little to no precipitation over the next 10-15 days, it is likely that short-term drought conditions will develop 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>.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/06\/pw_gefs-1.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-4921\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/06\/pw_gefs-1.png\" alt=\"\" width=\"700\" height=\"243\"\/><\/a><\/p>\n<p>Below we describe each of the two identified precipitation events in more detail.<\/p>\n<h3><strong>Event #1: Saturday (6\/17) and Sunday (6\/18)<\/strong><\/h3>\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>, short-term heavy rainfall possible but <span style=\"color: #0000ff;\"><strong>No Anticipated Flood Threat<\/strong><\/span><\/p>\n<p>A Pacific-origin cool front will come in from the north, being supported by a <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> feature embedded within a seasonably strong <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;jet stream&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Relatively strong winds concentrated within a narrow stream in the atmosphere. General weather patterns are related closely to the position, strength and orientation of the jet stream.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>jet stream<\/span>. For Colorado, the main chance of precipitation will arise due to the low-level forcing as aloft, a weak ridge will remain the status quo. A modest amount of moisture will be available 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> 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> shower and storm activity both days. Using climatology as guidance, the highest chances for precipitation will be in the foothills above 6,000 feet east 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>. Additionally, some storms may develop along the frontal feature towards the Kansas border. However, we do not expect <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> precipitation exceeding 1.0 inch, and thus, a flood threat is currently not warranted. Stay tuned to daily Flood Threat Bulletins for a more detailed assessment each morning.<\/p>\n<div style=\"position: relative;\"><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/06\/FTO_20170615_e1.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-4963\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/06\/FTO_20170615_e1.png\" alt=\"\" width=\"880\" height=\"500\"\/><\/a><\/div>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/05\/Legend.png\"><img loading=\"lazy\" class=\"alignnone size-full wp-image-230\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/05\/Legend.png\" alt=\"Legend\" width=\"94\" height=\"158\"\/><\/a><\/p>\n<h3><strong>Event #2: Thursday (6\/22) and Saturday (6\/24)<\/strong><\/h3>\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>, short-term heavy rainfall but <span style=\"color: #0000ff;\"><strong>No Anticipated Flood Threat<\/strong><\/span> as subsidence from ridge aloft negates low-level moisture<\/p>\n<p>There will not be much change in the atmospheric pattern from Event #1 to #2 as a strong jet will continue to stay north of Colorado, with a subtropical jet continuing the feed of dry air from the southwest. A ripple in the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;jet stream&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Relatively strong winds concentrated within a narrow stream in the atmosphere. General weather patterns are related closely to the position, strength and orientation of the jet stream.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>jet stream<\/span> is expected to send a cool front and weak upper-level dynamics across eastern Colorado starting Thursday and Friday, with residual moisture supporting more activity on Saturday. The nature of the activity will be similar to Event #1. On Thursday and Friday, expect <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 weak thunderstorms mainly in northeast Colorado as well as the higher elevations of south-central Colorado. On Saturday, expect 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> shower and storm activity mainly in the Southeast Mountains and Southeast Plains. In all, we do not foresee <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> amounts above 1 inch. While there will likely be short-term heavy rainfall, it will be too brief and limited in coverage to warrant a flood threat.<\/p>\n<div style=\"position: relative;\"><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/06\/FTO_20170615_e2.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-4964\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2017\/06\/FTO_20170615_e2.png\" alt=\"\" width=\"880\" height=\"500\"\/><\/a><\/div>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/05\/Legend.png\"><img loading=\"lazy\" class=\"alignnone size-full wp-image-230\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/05\/Legend.png\" alt=\"Legend\" width=\"94\" height=\"158\"\/><\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Thursday, June 15th, 2017 Issue Time: 2:50PM MDT Valid Dates: 6\/16 &ndash; 6\/30 This afternoon&rsquo;s North Pacific Ocean water vapor imagery, below, continues to show a zonally oriented, strong <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;jet stream&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Relatively strong winds concentrated within a narrow stream in the atmosphere. General weather patterns are related closely to the position, strength and orientation of the jet stream.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>jet stream<\/span> extending nearly to the North American coastline. While there has been a lot of variability in weather across the northwest U.S., our [&hellip;]<\/p>","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[3],"tags":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/4920"}],"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\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4920"}],"version-history":[{"count":3,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/4920\/revisions"}],"predecessor-version":[{"id":4966,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/4920\/revisions\/4966"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4920"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4920"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4920"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}