— A LOW<\/strong> flood threat has been issued for the 416 burn scar<\/em><\/p>\n
This morning’s visible satellite image, below, reminds us that monsoon<\/span> season is here, even if its start has been modest. Within the clockwise flow around a strengthening upper-level ridge over Texas is an embedded rather strong but small-scale shortwave<\/span>. Its southerly origin is a common feature of monsoon<\/span> dynamics. It is already causing mainly mid and high clouds with some light showers over the Four Corners region. It is anticipated to slowly move across the southeast quadrant of Colorado today, causing scattered<\/span> to numerous<\/span> shower and thunderstorm activity for the third day in a row. Flood threat aside, no complaints for a region that has been plagued by a worsening drought.<\/p>\n Taking a closer look at heavy rainfall parameters, a PW<\/span> of 0.59 inches was measured at Denver this morning, which is below normal for this time of year. The Grand Junction radiosonde launch was not successful, but we estimate a PW<\/span> of about 0.5 inches there, also below seasonal normal. However, the PW<\/span> at North Platte, Nebraska (1.21 inches), Dodge City, Kansas (1.35 inches), and Albuquerque, New Mexico (1.00 inch) were all at or above seasonal normal. This implies that a strong moisture gradient exists to our south and east. Most notable is the value from Albuquerque, since that is where today’s air mass will be coming from. Importantly, it appears model initialization is underestimating the moisture content in northern New Mexico today, with model estimate PW<\/span> of about 0.85-0.90 inches at Albuquerque, about 15% below the observed value.<\/p>\n A look at our high-resolution guidance today shows underwhelming maximum 1-hour rainfall intensity (see below). Keeping in mind guidance is almost always biased high across the San Juan Mountains, it appears that guidance is underestimating rain intensity east of the Continental Divide<\/span>. This is likely because of the propensity to mix out low-level moisture too quickly at this point in the summer. Accounting for this, we are issuing a Low flood threat for a large portion of southeast Colorado, but also including the eastern part of the San Juan mountains today. The 416 burn scar is also under a Low threat, because of the potential for multiple bursts of short-term heavy rainfall that will elevate the threat for mud flows.<\/p>\n East of the Continental Divide<\/span>, large hail will also be possible with the strongest storms along with a slight chance of tornadoes.<\/p>\n![\"\"](\"https:\/\/archive-coftb.dewberryanalytics.com\/wp-content\/uploads\/2020\/07\/wv_markup-3.png\")
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