{"id":2860,"date":"2016-06-23T14:22:35","date_gmt":"2016-06-23T20:22:35","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=2860"},"modified":"2016-06-23T14:23:03","modified_gmt":"2016-06-23T20:23:03","slug":"fto-06-23-2016-active-period-underway-east-of-the-divide-warm-and-mainly-dry-west-jury-still-out-on-monsoon-watch","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=2860","title":{"rendered":"FTO 06-23-2016: Active Period Underway East of the Divide; Warm and Mainly Dry West; Jury Still Out On Monsoon Watch"},"content":{"rendered":"<p>Issue Date: Thursday, June 23rd, 2016<br>\nIssue Time: 2:20PM MDT<br>\nValid Period: June 24th through July 8th<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2016\/06\/threat_timeline1.png\"><img loading=\"lazy\" class=\"aligncenter  wp-image-2863\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2016\/06\/threat_timeline1.png\" alt=\"threat_timeline\" width=\"880\" height=\"117\"\/><\/a><\/p>\n<p>Today&rsquo;s water vapor image over the North Pacific Ocean and North American continent, below, shows an active pattern with <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> low-pressure centers embedded 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>. Of these, the disturbance currently entering the Pacific Northwest and the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;cut-off low&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;an upper-level low pressure system that has been &amp;quot;cut off&rdquo; from the prevailing winds that steer weather systems; cut-off lows typically become stationary or move very slowly, bringing prolonged periods of unsettled weather&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>cut-off low<\/span> southwest of California appear to play prominent roles in our state&rsquo;s weather over the next two weeks. Also of interest is the high-pressure center in the southern Gulf of Alaska. This feature will slowly move eastward and then park itself roughly over the climatologically preferred position centered on western North America.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2016\/06\/wv_markup11.png\"><img loading=\"lazy\" class=\"aligncenter  wp-image-2864\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2016\/06\/wv_markup11.png\" alt=\"wv_markup\" width=\"663\" height=\"368\"\/><\/a><\/p>\n<p>In fact, long-range guidance suggests that the mean circulation over the next 7-14 days will be marked by this high-pressure ridge. Using the Climate Prediction Center&rsquo;s best analogs of forecasted mid-level flow centered on day 7 (June 30<sup>th<\/sup>), the maps below show that the anomalous ridge should assume a position roughly centered over Washington state and British Columbia. This pattern is far enough northwest of Colorado that the eastern part of our state should see its fair share of weather patterns that transition around this ridge. For example, the right map below shows the composite precipitation anomalies that occur during the forecasted flow. Note that historically, eastern Colorado, in particular the southeast, receives above average precipitation during this kind of flow. Lastly, we are also keeping a close <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;Watch&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;a weather watch is issued when conditions are favorable for a specific weather event to occur&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>watch<\/span> on the southwest <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;monsoon&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;a seasonal wind that brings moisture and rain to the region into which it blows; there is also a dry phase to monsoons, but popular usage refers only to the wet phase; these winds occur in many places around the world, and where they occur they are responsible for a majority of that location&rsquo;s annual precipitation&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>monsoon<\/span>, which at this time appears to be slightly behind schedule. There are some indications of several <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;monsoon&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;a seasonal wind that brings moisture and rain to the region into which it blows; there is also a dry phase to monsoons, but popular usage refers only to the wet phase; these winds occur in many places around the world, and where they occur they are responsible for a majority of that location&rsquo;s annual precipitation&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>monsoon<\/span>-type disturbances over the next 15 days, however, just like last Monday&rsquo;s FTO this is no the &ldquo;most likely outcome&rdquo;. With that said, it appears that western Colorado will continue to see generally dry and warm weather until the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;monsoon&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;a seasonal wind that brings moisture and rain to the region into which it blows; there is also a dry phase to monsoons, but popular usage refers only to the wet phase; these winds occur in many places around the world, and where they occur they are responsible for a majority of that location&rsquo;s annual precipitation&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>monsoon<\/span> flow can get established.<\/p>\n<p><a href=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2016\/06\/analog_comps.png\"><img loading=\"lazy\" class=\"aligncenter  wp-image-2862\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2016\/06\/analog_comps.png\" alt=\"analog_comps\" width=\"833\" height=\"310\"\/><\/a>We have identified three precipitation events over the next 14-day period. The first two events are very similar to those identified by the last FTO. Below, each event is described in detail.<\/p>\n<h3><strong>Event #1: Friday (6-24-2016) through Saturday (06-25-2016)<\/strong><\/h3>\n<p><span style=\"color: #0000ff;\"><strong>No Apparent Flood Threat<\/strong><\/span> but <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> light to moderate rainfall possible<\/p>\n<p>A large-scale disturbance, currently entering the northwest coast of US will come ashore and quickly &nbsp;trek across the northern tier of states on Friday and Saturday. It appears that each day will see a wave of afternoon shower and thunderstorm activity. The impacted region on Friday will be northeast Colorado, while on Saturday, the southeast part of the state will see the most <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. Given that this disturbance will only graze Colorado, upper-level dynamics will be rather limited. The main drivers will be a surface cool front and solar insolation. <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> pockets of heavy rainfall are possible east of the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;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\"}]'>Divide<\/span>, but in general we anticipate up to 1.25 inches of rainfall. Thus, an elevated flood threat is not warranted at this time, and the finer details will be covered by ensuing Flood Threat Bulletins.<\/p>\n<p><iframe loading=\"lazy\" src=\"https:\/\/a.tiles.mapbox.com\/v4\/sgeiger.0fo952mk\/attribution,zoompan,zoomwheel,geocoder,share.html?access_token=pk.eyJ1Ijoic2dlaWdlciIsImEiOiJmNjc5a3RBIn0.LbLupVkJsS5dbo9fsgrTDg\" width=\"100%\" height=\"500px\" frameborder=\"0\"><\/iframe><br><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: Tuesday (6-28-2016) through Thursday (06-30-2016)<\/strong><\/h3>\n<p><strong><span style=\"color: #0000ff;\">No Apparent Flood Threat<\/span><br><\/strong><\/p>\n<p>For several days following Event 1, the ridge is expected to re-exert dominance over the Rocky Mountain states. Then, current guidance suggests that the <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;cut-off low&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;an upper-level low pressure system that has been &amp;quot;cut off&rdquo; from the prevailing winds that steer weather systems; cut-off lows typically become stationary or move very slowly, bringing prolonged periods of unsettled weather&amp;lt;\/p&amp;gt;\n&amp;lt;!-- \/wp:paragraph --&amp;gt;&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>cut-off low<\/span> seen in the water vapor image will eventually be absorbed into the main flow and work its way around the anticipated northwest US ridge. Again, this will provide a &ldquo;northwest flow&rdquo; event, similar to Event 1. It is difficult for such events to produce prolonged and <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 because upslope flow is limited and followed by <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> westerly winds after event passage. Nonetheless, we expect several rounds of thunderstorms Tuesday and Wednesday and residual moisture to provide some higher elevation storms on Thursday. The target areas will be mainly 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>. As with Event #1, forecasted precipitation is expected to stay at or below 1.5 inches. Thus, no elevated threat is warranted at this time.<br><iframe loading=\"lazy\" src=\"https:\/\/a.tiles.mapbox.com\/v4\/sgeiger.0foa0h04\/attribution,zoompan,zoomwheel,geocoder,share.html?access_token=pk.eyJ1Ijoic2dlaWdlciIsImEiOiJmNjc5a3RBIn0.LbLupVkJsS5dbo9fsgrTDg\" width=\"100%\" height=\"500px\" frameborder=\"0\"><\/iframe><br><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 #3: Wednesday (7-7-2016) through Thursday (7-8-2016)<\/strong><\/h3>\n<p><span style=\"color: #0000ff;\"><strong>No Apparent Flood Threat<\/strong><\/span><\/p>\n<p>Another lull is expected after Event #2 where the ridge will strengthen and provide warm and dry weather for Colorado, especially on the western slope. At this time, guidance again suggests a breakdown of the expected ridge with another &ldquo;northwest flow&rdquo; event possible. At this time, the chances of this occurring are too low to produce a precipitation map. However, it appears that northern and eastern Colorado will be most under threat. The western part of the state is expected to remain very warm and mostly dry.<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Thursday, June 23rd, 2016 Issue Time: 2:20PM MDT Valid Period: June 24th through July 8th Today&rsquo;s water vapor image over the North Pacific Ocean and North American continent, below, shows an active pattern with <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> low-pressure centers embedded 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>. Of these, the disturbance currently entering the Pacific Northwest and the [&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\/2860"}],"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=2860"}],"version-history":[{"count":4,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/2860\/revisions"}],"predecessor-version":[{"id":2867,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/2860\/revisions\/2867"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2860"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2860"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2860"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}