{"id":14581,"date":"2021-06-25T10:40:16","date_gmt":"2021-06-25T16:40:16","guid":{"rendered":"https:\/\/www.coloradofloodthreat.com\/?p=14581"},"modified":"2021-06-26T07:39:36","modified_gmt":"2021-06-26T13:39:36","slug":"ftb-06-25-2021-heavy-rainfall-threat-returns-with-moisture-plume-and-training-storms","status":"publish","type":"post","link":"https:\/\/archive-coftb.dewberryanalytics.com\/?p=14581","title":{"rendered":"FTB 06-25-2021: Heavy Rainfall Threat Returns with Moisture Plume and Training Storms"},"content":{"rendered":"<p>Issue Date: Friday, June 25th, 2021<br>\nIssue Time: 10:40AM MDT<\/p>\n<p><em>&mdash; A <strong>MODERATE<\/strong> flood threat has been issued for portions of the Front Range and Urban Corridor<\/em><br><em> &mdash; A <strong>LOW<\/strong> flood threat has been issued for the Northwest Slope, Grand Valley, Northern Mountains, Central Mountains, Southeast Mountains, Palmer Ridge, Northeast Plains and Southeast Plains<\/em><\/p>\n<p>The moisture plume from the last couple days is still over the state, which can be seen by the blue and white shades in the water vapor imagery below and high <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;dew points&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The temperature to which a given air parcel must be cooled (at constant pressure and water vapor content) in order for saturation to occur.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>dew points<\/span> across the state (not shown). <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;dew points&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The temperature to which a given air parcel must be cooled (at constant pressure and water vapor content) in order for saturation to occur.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>Dew points<\/span> over northwest Colorado are around 50F (!), and Grand Junction&rsquo;s morning sounding is still showing elevated moisture throughout the atmosphere with <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> around 0.90 inches. It&rsquo;s the same story over eastern Colorado with <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;dew points&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;The temperature to which a given air parcel must be cooled (at constant pressure and water vapor content) in order for saturation to occur.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>dew points<\/span> in the mid to upper 50Fs and <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> around 0.85 inches (Denver). As the state transitions into a weak <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;trough&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;An elongated area of relatively low atmospheric pressure; the opposite of a ridge.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>trough<\/span> pattern today, mid-level lift will increase over the area. This paired with the higher moisture will aid in the development of <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> storms over the mountains and elevated ridges by noon. Storms are expected to spill into the adjacent eastern plains by mid-afternoon and as they encounter higher instability (east), storms are expected to intensify. So, expect some <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;severe thunderstorm&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Thunderstorms that produce a tornado, winds of at least 58 mph (50 kts) and\/or hail at least 1&amp;quot; in diameter.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>severe thunderstorm<\/span> over the far eastern plains that could produce 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 and large hail along with heavy rainfall. Early&nbsp;this evening, a weak cool front boundary will drop across the northern border, which will help to produce additional storms over the Urban Corridor, Palmer Ridge and eastern plains that are forecast to last into the overnight hours. So this is an overnight threat.<\/p>\n<p><span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;training&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Continuous or repeated rainfall over the same region&nbsp;in a relatively short time span. Training thunderstorms can produce very high rainfall totals and cause flash flooding.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>Training<\/span> storms and additional storms sparked by <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;outflow boundaries&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 boundaries<\/span> today are expected to produce high 30-minute rain rates and 2-3 hour accumulations, so a Low flood threat has been issued. Threats over the steeper terrains include mud flows, debris slides and road flooding. Although less convective storms are forecast overnight along the southern Front Range and Urban Corridor, persistent rainfall in the moisture-rich environment today and tonight are expected to produce local heavy rainfall with <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> 24-hour&nbsp;totals up to 2.75 inches by morning. Thus, a Moderate flood threat has been issued.<\/p>\n<p>Please check the Fire Burn Forecast Page as there are several elevated threats issued for the burn areas today.<\/p>\n<p><img loading=\"lazy\" class=\"aligncenter wp-image-14582\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/06\/wv_20210625.png\" alt=\"\" width=\"750\" height=\"477\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/06\/wv_20210625.png 1478w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/06\/wv_20210625-300x191.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/06\/wv_20210625-768x488.png 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/06\/wv_20210625-1024x651.png 1024w\" sizes=\"(max-width: 750px) 100vw, 750px\"\/><\/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. If there is a threat, hover over the threat areas for more details, and click on burn areas to learn more about them. For Zone-Specific forecasts, scroll below the threat map.<br><img loading=\"lazy\" class=\"aligncenter wp-image-14594\" src=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/06\/FTB_20210625_snap.png\" alt=\"\" width=\"880\" height=\"593\" srcset=\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/06\/FTB_20210625_snap.png 1782w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/06\/FTB_20210625_snap-300x202.png 300w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/06\/FTB_20210625_snap-768x517.png 768w, https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2021\/06\/FTB_20210625_snap-1024x690.png 1024w\" sizes=\"(max-width: 880px) 100vw, 880px\"\/><\/p>\n<h3><strong>Zone-Specific Forecasts:<\/strong><strong>&nbsp;<\/strong><\/h3>\n<h4><strong>Front Range &amp; Urban Corridor:<\/strong><\/h4>\n<p>Storms today are expected to fire over the high terrains by noon and move into the Urban Corridor by mid-afternoon. Initially, the convective storms will be possible of producing 1-hour rain rates up to 1.25 inches with two hour totals just over 2 inches. Behind a cool front tonight, persistent upslope flow will produce another round of showers in&nbsp;the Moderate threat area. <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> storm totals accumulations up to 2.75 inches will be possible by morning. Flood threats include road flooding and mud flows\/debris slides over steeper terrains.<\/p>\n<p>Primetime: 3PM to ongoing<\/p>\n<h4><strong>Grand Valley, Northwest Slope, Central Mountains &amp; Northern 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> storms are forecast to&nbsp;develop&nbsp;over the elevated mountains and ridges by late this morning as 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> energy moves overhead. Max 1-hour rain rates up to 0.75 inches will be possible, and 2-hour totals from <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;training&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Continuous or repeated rainfall over the same region&nbsp;in a relatively short time span. Training thunderstorms can produce very high rainfall totals and cause flash flooding.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>training<\/span> storms could produce <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> totals up to 1.50 inches. Flood threats include mud flows, debris slides and road flooding over steeper terrains. Linger rainfall is likely over the mountains and Northwest Slope overnight. A Low flood threat has been issued.<\/p>\n<p>Primetime: 11AM to Midnight<\/p>\n<h4><strong>Palmer Ridge, Northeast Plains &amp; Southeast Plains:<\/strong><\/h4>\n<p>Ongoing rainfall over the northeast corner will continue and may intensify a bit this morning. Some <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;severe thunderstorms&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Thunderstorms that produce a tornado, winds of at least 58 mph (50 kts) and\/or hail at least 1&amp;quot; in diameter.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>severe thunderstorms<\/span> are possible this afternoon further east where there is some better instability as storms move in from the west. The main threats from those storms will be heavy rainfall, large hail and 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. Max 1-hour rain rates up to 1.75 inches (north) and 1.25 inches (south) will be possible. <span class=\"glossaryLink\" aria-describedby=\"tt\" data-cmtooltip=\"&lt;div class=glossaryItemTitle&gt;training&lt;\/div&gt;&lt;div class=glossaryItemBody&gt;Continuous or repeated rainfall over the same region&nbsp;in a relatively short time span. Training thunderstorms can produce very high rainfall totals and cause flash flooding.&lt;\/div&gt;\" data-gt-translate-attributes='[{\"attribute\":\"data-cmtooltip\", \"format\":\"html\"}]'>Training<\/span> storms (north) may produce 2 to 3 hour totals up to 2.50 inches, which could cause local flooding of streams, road and field ponding. A Low flood threat has been issued. Late night storms\/showers are possible over the Palmer Ridge, but rain rates should remain under 0.60 inches.<\/p>\n<p>Primetime: 3:30PM to Midnight<\/p>\n<h4><strong>Southwest Slope, San Juan Mountains, San Luis Valley, Raton Ridge and Southeast 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> afternoon storms are expected over these regions with more coverage east than west. Max 1-hour rain rates up to 0.40 inches are possible over the mountains with storm totals just over 0.50&nbsp;inches possible (west). Over the Raton Ridge, max 1-hour rain rates up to 0.60 inches are possible. A second round of overnight showers are possible in the Southeast and San Juan Mountains, and flooding is NOT forecast.<\/p>\n<p>Primetime: 1PM to 1AM<\/p>","protected":false},"excerpt":{"rendered":"<p>Issue Date: Friday, June 25th, 2021 Issue Time: 10:40AM MDT &mdash; A MODERATE flood threat has been issued for portions of the Front Range and Urban Corridor &mdash; A LOW flood threat has been issued for the Northwest Slope, Grand Valley, Northern Mountains, Central Mountains, Southeast Mountains, Palmer Ridge, Northeast Plains and Southeast Plains The [&hellip;]<\/p>","protected":false},"author":8,"featured_media":0,"comment_status":"closed","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\/14581"}],"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=14581"}],"version-history":[{"count":4,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/14581\/revisions"}],"predecessor-version":[{"id":14596,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=\/wp\/v2\/posts\/14581\/revisions\/14596"}],"wp:attachment":[{"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=14581"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=14581"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive-coftb.dewberryanalytics.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=14581"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}