{"id":9589,"date":"2019-06-27T14:34:28","date_gmt":"2019-06-27T20:34:28","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=9589"},"modified":"2019-07-01T12:11:28","modified_gmt":"2019-07-01T18:11:28","slug":"fto-06-27-2019-heavy-rainfall-anticipated-as-high-precipitable-water-values-are-pulled-into-colorado","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=9589","title":{"rendered":"FTO 06-27-2019: Heavy Rainfall Anticipated as High Precipitable Water Values Are Pulled into Colorado"},"content":{"rendered":"<p>Issue Date: Thursday, June 27th, 2019<br>\nIssue Time: 2:45PM MDT<br>\nValid Dates: 6\/28 &ndash; 7\/12<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/06\/FTO_20190627.png\"><img loading=\"lazy\" class=\"alignnone wp-image-9590\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/06\/FTO_20190627.png\" alt=\"\" width=\"880\" height=\"154\"\/><\/a><\/p>\n<p>Looks like that summer atmospheric pattern is finally here to stay. The polar jet has finally pulled to the north, which has allowed some very hot temperatures to fester over the state since Monday. The 5580m line (weak ridge) will remain well to the north of the state through next Monday with the main axis to our east. This will continue southwest flow aloft and keep hot temperatures in the forecast through this weekend. Movement of the axis further east will allow ample low level moisture to return to the state, and may pull in remnants of Tropical Storm Alvin (off the coast of Mexico) over the southwest corner of the state as soon as Friday. By Sunday evening, flow will start to become more <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;zonal&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;refers to the east-west direction; usually used to describe atmospheric flow that roughly follows lines of latitude&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>zonal<\/span> as the ridge breaks down, and a weak cold front will pass through the state overnight. Westerly flow aloft through Tuesday will keep high <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> values over eastern Colorado. Flow aloft turns to the northwest after Tuesday, which should end Event #1.<\/p>\n<p>Not much, if any time between Event #1 and Event #2. Ample moisture remains in place after Tuesday for <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> afternoon storms, but the flood threat should decrease. By the holiday weekend, the upper level ridge will set back up with the ridge of the axis possibility setting up to the east once again. This would allow low level moisture to rotate around the high and return the flood threat. Still quite a bit of uncertainty at this time, but overall, doesn&rsquo;t look like there will be much dry or too cool of temperatures this next forecast period.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/06\/wv_20190627.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-9591\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/06\/wv_20190627.png\" alt=\"\" width=\"750\" height=\"588\"\/><\/a><\/p>\n<p><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> values look to increase statewide to much above average values for this time of year by this weekend, and then last through next Tuesday. Monday&rsquo;s FTO&rsquo;s <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> values showed an increase, but not with the certainty, magnitude and timing of the latest GEFS runs. This will return the flood threat both east and 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> and increase the threat level to an Elevated\/High threat at the end of this weekend. It has been dry and hot over western Colorado with <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;critical fire weather&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;weather conditions especially conducive to the formation of wildfires; typically strong winds, low relative humidity, and atmospheric instability&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>critical fire weather<\/span> yesterday, today and again tomorrow. The absorption of moisture into the westerly flow from Tropical Storm Alvin over southwest CO begins on Friday, which should reduce fire danger and increase the chances for measurable rain this weekend. The 416 burn area will be monitored closely due to the uptick in moisture from Saturday to Monday. To the east, <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> values peak well above the 1 inch mark on Sunday and Monday. Reminder that the 1 inch <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> value is a good indicator of heavy rainfall if both lift and instability are also available. Slow steering winds under the ridge over eastern Colorado will also allow storms to drop heavier accumulations. Recent burn areas will be extra susceptible to flooding during Event #1. After Monday, dry weather is expected to return to western Colorado with the ridge axis to our west. Moisture will also briefly decrease to more seasonable values over eastern Colorado, so there is No Apparent Threat at this time.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/06\/PW_20190627.png\"><img loading=\"lazy\" class=\"alignnone wp-image-9592\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/06\/PW_20190627.png\" alt=\"\" width=\"880\" height=\"305\"\/><\/a><\/p>\n<h4><strong>Snowpack:<\/strong><\/h4>\n<p>The flooding threat has decreased over the state the last couple of days with only one gage remaining at Action stage this morning (Rio Grande at Alamosa). The flow is anticipated to remain steady at the gage with only a slight increase this weekend thanks to multiple days of hot temperatures. Taking a look at the statewide <span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;SWE&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;&amp;lt;strong&amp;gt;S&amp;lt;\/strong&amp;gt;now &amp;lt;strong&amp;gt;W&amp;lt;\/strong&amp;gt;ater &amp;lt;strong&amp;gt;E&amp;lt;\/strong&amp;gt;quivalent, the liquid water content of snowpack&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\"  data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>SWE<\/span> below, you can pick out the spring snow storms that have occurred over the last couple months and have stalled the melting process (and even added to <span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;SWE&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;&amp;lt;strong&amp;gt;S&amp;lt;\/strong&amp;gt;now &amp;lt;strong&amp;gt;W&amp;lt;\/strong&amp;gt;ater &amp;lt;strong&amp;gt;E&amp;lt;\/strong&amp;gt;quivalent, the liquid water content of snowpack&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\"  data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>SWE<\/span>). While we will come close to the 1995 record for longest lasting <span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;SWE&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;&amp;lt;strong&amp;gt;S&amp;lt;\/strong&amp;gt;now &amp;lt;strong&amp;gt;W&amp;lt;\/strong&amp;gt;ater &amp;lt;strong&amp;gt;E&amp;lt;\/strong&amp;gt;quivalent, the liquid water content of snowpack&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\"  data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>SWE<\/span>, we likely won&rsquo;t beat it with summerlike temperatures forecast. RFCs (River Forecast Centers) are forecasting another rise in smaller, high-elevation rivers and streams by later this weekend, which may cause a couple AHPS gages to reach Action stage. Rain forecasts will be monitored closely during this peak as some heavier, <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> rainfall will be possible. This may cause some minor flooding issues while the rivers are swollen from snowmelt, but at this time, no major riverine flooding is anticipated. As anticipated, there are currently no <span class=\"glossaryLink\"  aria-describedby=\"tt\"  data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;NWS&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;National Weather Service&lt;\/div&gt;\"  data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>NWS<\/span> Areal Flood Advisories or Warnings. This will likely be the last FTO with the snowpack update, but riverine flooding will continue to be monitored throughout the season.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/06\/SWE_20190627.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-9593\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/06\/SWE_20190627.png\" alt=\"\" width=\"600\" height=\"559\"\/><\/a><\/p>\n<h3><strong>Event #1: Friday (6\/28) &ndash; Tuesday (7\/2)<\/strong><\/h3>\n<p><span style=\"color: #0000ff;\"><strong>No Apparent Threat<\/strong> <\/span>&ndash; <span style=\"color: #ff0000;\"><strong>High Threat <\/strong><\/span><em>as eastward movement of a weak ridge allows ample low level moisture from the Gulf of Mexico and Tropical Storm Alvin to move into the state. <\/em><\/p>\n<p>Deep moisture will return to the state beginning this weekend. This will return the flood threat as heavy rainfall with slow steering winds combine for a High threat on Monday. Storms will initiate over the mountains each afternoon and will likely be confined to that area and immediate adjacent plains through this event. The main reason for this is the only forcing mechanism available will be the diurnal upslope pattern. Storms will likely survive best over the Palmer and Raton Ridges as they move east. By Sunday, storms over the mountains will be capable of producing <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>, heavy rainfall with very high <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> values anticipated over the state. This could easily cause some flooding issues, especially over recent burn scars in the Southeast Mountains and San Juan\/Central Mountains. Thunderstorms chances increase for the plains on Monday and Tuesday. These storms will also be capable of producing heavy rainfall as well as some severe weather over the Northeast Plains thanks to passing cold fronts adding dynamics to the atmosphere. Still quite a bit of uncertainty with how each day will unfold Sunday-Tuesday, so please tune back into the daily FTB for the latest details.<\/p>\n<div style=\"position: relative;\"><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/06\/FTO_20190627_e1.png\"><img loading=\"lazy\" class=\"aligncenter wp-image-9635\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/06\/FTO_20190627_e1.png\" alt=\"\" width=\"880\" height=\"499\"\/><\/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<p>&nbsp;<\/p>\n<h3><strong>Event #2: <\/strong><strong>Wednesday<\/strong><strong> (<\/strong><strong>7\/3<\/strong><strong>) &ndash; <\/strong><strong>Sunday<\/strong><strong> (7\/<\/strong><strong>7<\/strong><strong>)<\/strong><\/h3>\n<p><span style=\"color: #0000ff;\"><strong>No Apparent Threat<\/strong><\/span><strong>\/<span style=\"color: #ff6600;\">Elevated Threat<\/span><\/strong><em> northwest flow brings a brief break in heavy rainfall before the next ridge sets up and potentially shifts slightly to the east allowing gulf moisture to increase over eastern Colorado. <\/em><\/p>\n<p>Models hint at a ridge rebuilding north of Colorado for the holiday weekend. This would return hot temperatures to the forecast statewide. Eastward movement of the ridge on Saturday night, along with passing shortwaves rotating around the high, would return the flood threat. High <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> values would be advected north over eastern Colorado in this scenario. Moisture is also expected to increase over western Colorado again, so rainfall will likely return to the forecast there as well. Still quite a bit of uncertainty this far out. Tune back into the FTO on Monday for the latest details on rainfall chances for the 4<sup>th<\/sup> of July weekend.<\/p>\n<div style=\"position: relative;\"><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/06\/FTO_20190627_e2.png\"><img loading=\"lazy\" class=\"alignnone wp-image-9636\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2019\/06\/FTO_20190627_e2.png\" alt=\"\" width=\"880\" height=\"494\"\/><\/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 27th, 2019 Issue Time: 2:45PM MDT Valid Dates: 6\/28 &ndash; 7\/12 Looks like that summer atmospheric pattern is finally here to stay. The polar jet has finally pulled to the north, which has allowed some very hot temperatures to fester over the state since Monday. The 5580m line (weak ridge) will [&hellip;]<\/p>","protected":false},"author":8,"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\/9589"}],"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=9589"}],"version-history":[{"count":3,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/9589\/revisions"}],"predecessor-version":[{"id":9638,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/9589\/revisions\/9638"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=9589"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=9589"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=9589"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}