{"id":636,"date":"2015-05-31T09:12:06","date_gmt":"2015-05-31T15:12:06","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=636"},"modified":"2017-04-24T17:46:37","modified_gmt":"2017-04-24T23:46:37","slug":"stp-05-31-2015-a-handful-of-storms-beat-the-odds-but-little-rainfall","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=636","title":{"rendered":"STP 05-31-2015: A Handful Of Storms Beat The Odds, But Little Rainfall"},"content":{"rendered":"<p>Issue Date: Sunday, May 31th, 2015<br>\nIssue Time: 9:05 AM MDT<\/p>\n<h3>Summary:<\/h3>\n<p>With a ridge overhead, thunderstorm activity was effectively squashed statewide on Saturday. By late afternoon, a few rogue storms were able to form over the Northwest Slope, Front Range and Southeast Mountains. However, the storms looked more impressive that they actually were: highest observed rainfall was only 0.05 inches. No flooding was reported yesterday. See our map below for the radar estimated rainfall in your area.<\/p>\n<p>We are taking this lull in action to begin to appreciate just how active May was; not so much from the flooding aspect, but certainly from the total precipitation aspect. One tool we commonly use for our Flood Threat Bulletin forecasts is 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>). This measures the amount of water vapor (not liquid, only gaseous water!) in the overhead column of atmosphere. In Colorado, when <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> exceeds about 0.7 inches, this may be the first indication of a heavier rainfall threat. When values exceed 1 inch, there is a very high likelihood of action somewhere in the state. The charts below, courtesy of NOAA&rsquo;s Earth System Research Lab, show the <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> from this past May. The 0.7 inch line is marked by a thick black line. Impressively, during almost every day except for a handful, <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> exceeded 0.7 inches in at least one of the three main stations we use: Pueblo (purple), Grand Junction (green) and Boulder (blue).<\/p>\n<div style=\"position: relative;\"><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/05\/IPW_historical.png\"><img loading=\"lazy\" class=\"aligncenter  wp-image-638\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/05\/IPW_historical.png\" alt=\"IPW_historical\" width=\"468\" height=\"600\"\/><\/a>So how does this compare to normal? Well, we also included a chart of 2014, a more typical year. Note that only 7-10 days exceeded the 0.7 inch threshold. Meanwhile, also shown is 2012, the year of an intense spring\/summer drought. Note that during that year only a couple of days exceeded PWs of 0.7 inches, but Grand Junction did not exceed 0.7 inches for the entire month! This is a quick way to get a perspective on just how unusual this May has been.<br><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/06\/20150531_STPImage.png\"><img loading=\"lazy\" class=\"alignnone size-full wp-image-648\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/06\/20150531_STPImage.png\" alt=\"20150531_STPImage\" width=\"890\" height=\"500\"\/><\/a><br><img loading=\"lazy\" class=\"alignright wp-image-136\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2015\/04\/stormtotalprecip_legend.png\" alt=\"Storm Total Precip Legend\" width=\"470\" height=\"32\"\/><\/div>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Sunday, May 31th, 2015 Issue Time: 9:05 AM MDT Summary: With a ridge overhead, thunderstorm activity was effectively squashed statewide on Saturday. By late afternoon, a few rogue storms were able to form over the Northwest Slope, Front Range and Southeast Mountains. However, the storms looked more impressive that they actually were: highest [&hellip;]<\/p>","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[4],"tags":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/636"}],"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=636"}],"version-history":[{"count":8,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/636\/revisions"}],"predecessor-version":[{"id":4259,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/636\/revisions\/4259"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=636"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=636"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=636"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}